Describe Network Architectures

0:00[MUSIC PLAYING]

0:07Hello, and welcome to describe network architectures.

0:11In this skill, we're going to jump in and just get

0:15a basic overview of a lot of the different technologies used

0:19inside of today's service provider environments.

0:23Now, as I said, for most of these topics

0:27this is just going to be an introduction.

0:30Things like MPLS and segment routing

0:34we're going to be covering in much more detail

0:37in future skills but this is going

0:39to introduce us to the idea.

0:41So we do have quite a few things to cover here.

0:44So let's just jump in and get started.

0:46I'll see you in the next video.

0:07So let's start by jumping in and simply

0:10taking a look at some of the technologies, designs,

0:14and services that we're going to be using in today's service

0:18provider networks.

0:21First, let's talk about the different types of traffic

0:23that we need to provide for our customers.

0:27Now, the first thing on our list here is, of course,

0:29IP traffic or internet traffic.

0:32This, of course, is probably the main thing

0:34people think of when they think of a service provider.

0:38However, in today's environment, a lot of times

0:42we'll be providing other services such as IPTV.

0:46And that may not be a service like going directly

0:49to the customer.

0:50It may just be for the service provider themselves.

0:53For example, in a cable provider,

0:56this could often be the signal going to the cable box

1:00that the person then watches on their television.

1:02They might not even be aware of the fact

1:04that this is streaming over IP.

1:07Voice over IP is also a very common service

1:10for service providers today where

1:12we can get bundles of our TV, our internet, and our phone,

1:16for our home phone if anybody still is using those.

1:19I personally have one.

1:20Couldn't tell you the phone number.

1:21And I don't even know the last time I used it.

1:23But nonetheless, it is a service that many service providers

1:26do have available.

1:27And of course, mobility--

1:29this would mostly tie-in to say, for example,

1:33a cellular service provider--

1:353G, 4G, 5G services where the person's roaming all over

1:41and they still need to have connectivity back

1:43through their service provider.

1:45Now, to support these we do have a few different design

1:48principles we want to talk about.

1:50The first, of course, being a modular design.

1:54We're going to build our service provider network out

1:56very modular, and then we connect those modules

2:00through the core network.

2:02This is quite commonly running MPLS or Multi-Protocol Label

2:08Switching.

2:08We'll talk more about the advantages

2:10of using MPLS as we work our way through this skill.

2:14But this is what's commonly done in the core of the service

2:17provider network.

2:19But just to get some of those advantages

2:20out here a little bit, the advantage of using MPLS

2:23in the core is we can, of course, provide

2:26that internet access, we can offer the customers VPN,

2:30we can offer telephony, and we can offer quality

2:34of service just to name a few.

2:36Other things such as traffic engineering and so on we

2:40will get into.

2:41This also lays the foundation for things

2:43like segment routing, and a lot of the other technologies

2:46we're going to be talking about both in this skill

2:48and in future skills.

2:50And one of the big advantages here for the service provider

2:54is all of this is available while only

2:57using IP in the core.

2:59The MPLS is running on top of the IP,

3:02which means the actual core devices are

3:05far more simple that they're just running IP with MPLS.

3:09They don't have to be aware of all of these other services.

3:13Now, in order to carry this traffic through the core,

3:16we have various different technologies

3:18available to our service provider environments.

3:22We have Wavelength division Multiplexing or WDM,

3:26then we have dense wavelength division multiplexing,

3:29which is the one I've seen far more often.

3:31It's a more current version of WDM.

3:34The "dense" meaning we're getting more wavelengths

3:37through the fiber.

3:38Both of these technologies would be something

3:40that we would be using most likely

3:42in the core of the service provider network.

3:45And then on the edge towards the customer,

3:48we would have things like DSL, cable services, ethernet,

3:53and Gigabit Passive Optical Network or GPON.

3:57These are different technologies we

3:58can have on the edge towards the customer.

4:01And then, of course, various wireless technologies--

4:043G, 4G, 5G.

4:07In some locations, you can actually just

4:09get flat out Wi-Fi from your service provider.

4:12My service provider where I live has Wi-Fi service.

4:16Now, they don't have it where I actually

4:18live in my development.

4:21But if I go downtown, I can see the local service providers

4:26wireless network, and I use my log in

4:28and I can get right on their wireless.

4:30So they have actual Wi-Fi in the more densely populated areas,

4:35generally not in neighborhoods and such.

4:37But this is a service that they can make available

4:40if they choose to.

4:43In this video, we just jumped in and got an introduction

4:47to some of the technologies that we're

4:48going to be dealing with throughout this skill

4:51and others that are going to be used inside the service

4:54provider network.

4:56I hope this has been informative for you.

4:58And I'd like to thank you for viewing.

0:08Now it's time to jump in and just

0:10begin our discussion on MPLS, or multiprotocol label switching.

0:16Now this is obviously a very large topic.

0:20We have many skills on this later in this course.

0:24However, in this video, we're just

0:26going to jump in and get our feet wet with some

0:28of the ideas behind MPLS.

0:31The idea mostly being that, instead of forwarding traffic

0:35based on IP address in our core, we're

0:39going to be forwarding traffic based on labels.

0:42And those labels can come from a lot of different sources,

0:46but in the case of just, for example, IP forwarding,

0:49we would exchange those labels through something

0:52called LDP, which we'll also be getting into in a little bit.

0:57So for this video, let's just jump in

0:59and get started on the basics.

1:00Believe me, there's a lot more to come in future skills,

1:04but the idea behind this video is just

1:07to get started and get an idea on what MPLS actually is.

1:12The first thing we'll get out of the way with MPLS

1:15is where it actually operates, and the fact of the matter

1:19is, it operates between Layer 2 and Layer 3 of the OSI model.

1:26What that means effectively is we could have

1:29our original Layer 2 header.

1:32Then we insert our MPLS label.

1:36And then after this, would be the original Layer 3.

1:41Now that original Layer 3 can really be anything.

1:44We will be talking, of course, much about IPv4 or IPv6,

1:49but the fact of the matter is whatever Layer 3 transport.

1:52So we are inserting this MPLS header

1:56in between Layer 2 and Layer 3.

2:00We will often hear this referred to as a shim header.

2:04But whatever we call it, we need to understand

2:07that it goes between Layers 2 and 3,

2:09and as we said during the introduction,

2:12this means that the forwarding through our MPLS environment

2:17uses that label.

2:19Once this MPLS label is inserted,

2:22we no longer look at the IP header

2:26or really whatever this original Layer 3 header was.

2:29That Layer 3 header is now hidden from the P routers

2:34in the middle, or the provider routers.

2:37All they see is the MPLS label.

2:39The labels used across an entire path

2:43make up something called the label switch path, or the LSP.

2:48So if we were talking about forwarding traffic

2:50through, say, four routers then there

2:53would be four labels in our label switch path.

2:56The labels get swapped hop-by-hop as they pass through

3:00the core--

3:01at least the forwarding labels do.

3:03We'll get into label stacks and things

3:06like this in some future skills.

3:09This is just, again, an introduction.

3:11But the forwarding label will get switched as the packet

3:14moves through the MPLS core.

3:16That means that this label switch path is unidirectional.

3:22Traffic going the other way will use

3:25completely different labels.

3:27So basically, what this means is if I

3:30were to ping through the MPLS environment,

3:33the ICMP echo request going to the destination

3:37would take one particular label switch path.

3:40The ping reply coming from that device

3:45would use a completely different label switch path on the way

3:48back.

3:49That's what we mean by the fact that it's unidirectional.

3:52The traffic itself, of course, will

3:55flow both directions, or else this wouldn't be very useful.

3:59We simply mean that the labels being

4:01switched on a particular path is only for traffic going one way.

4:06And don't think necessarily either that the traffic coming

4:10back would be the complete opposite label switch

4:13path because that's often not true either.

4:16It could be, but that would honestly just

4:19be by random luck.

4:21Normally, these paths are totally and completely

4:23independent.

4:24It's whatever labels the devices come up

4:27with for the different destination networks.

4:30Again, we'll see this in much more detail

4:32in some future skills.

4:35Now again, the big advantage to all of this

4:37is this label switch path can really carry any payload.

4:41That's why this is called multi-protocol.

4:44It can carry Layer 2 or Layer 3.

4:47And again, we'll see this in more detail in future skills

4:50as well.

4:51This can carry any payload we need it to.

4:53It just needs a label.

4:55So the fact that we can carry any payload really

4:58allows us to support a large number of services.

5:02So as we mentioned, of course internet access

5:04is going to be one of those, but also Layer 2 and Layer 3 VPNs

5:09support for customers as well as things

5:13like traffic engineering, any transport over MPLS

5:17to support Layer 2 services, as well as things

5:20like segment routing and so on.

5:22There's quite a few different services

5:24that we can offer with MPLS.

5:28Now just a quick note down here at the bottom--

5:30notice what we're saying here is that MPLS doesn't really

5:34offer a performance increase.

5:36Now the reason I'm bringing this up

5:38is if you read documentation just on MPLS and not

5:44necessarily specifically on Cisco equipment,

5:47you'll see a lot of references to MPLS really

5:50being a big help when it comes to performance as

5:54far as forwarding.

5:56So I wanted to put a little note on here that it doesn't really

6:00help on Cisco equipment.

6:02All of our modern Cisco equipment

6:04uses something called CEF, which you can see referenced down

6:07here, Cisco Express Forwarding.

6:10And CEF is used for both IPv4 forwarding and MPLS.

6:16And in fact, just as a side note in our side note here,

6:20MPLS flat out requires CEF.

6:23You cannot turn off scef and still run MPLS on Cisco

6:28equipment.

6:28So it requires it.

6:31But the point is mostly this--

6:33CEF is either the forwarding mechanism we're using

6:37in software on some of the lower-end routers,

6:39but on most of our high-end routers, CEF or DCEF--

6:44distributed CEF-- is done in hardware on the line cards,

6:48and as such, we're forwarding in hardware,

6:52either based on IP header or the MPLS label.

6:58So my point is, if we're doing hardware forwarding,

7:02it really doesn't matter if we're forwarding based

7:04on the IP address or the label.

7:06We're going to get the same performance level.

7:09So there's really not a performance gain

7:12from using MPLS.

7:14What we're really after is everything else

7:17we just talked about--

7:18all these different services that we

7:20can provide for our customers while still supporting

7:24just an IP infrastructure.

7:26That's what we're really after.

7:28That's the main gain with MPLS.

7:32So we have a bit more to go over.

7:34Let's clear this off.

7:36We have some other major advantages to this architecture

7:40of using MPLS.

7:42For example, only the PE routers,

7:45or the provider edge routers, need to do routing lookups.

7:49All the devices in the cores are not

7:51required to keep customer information.

7:54They do not need customer information.

7:57So this significantly cuts down on the forwarding tables

8:02on core routers, allowing them, of course, to scale

8:05to much larger environments.

8:08Also we can support non-IP protocols.

8:12Again, MPLS stands for multiprotocol,

8:16so we can support Layer 2 traffic directly over MPLS.

8:21Really, we can forward almost anything.

8:23And of course, all of these things

8:25together allow for much greater scalability,

8:28which, of course, is going to be of great concern in a service

8:31provider, so we get proper return on investment

8:35for all of our equipment.

8:36Now these routers that we keep referring

8:38to in the MPLS environment are referred to as label switch

8:43routers, or LSRs, and we do have several types of these.

8:48First, we have the ingress LSR.

8:50This is the device that actually pushes

8:53the label onto the packet as it comes in from the customer.

8:57Again, this is going to be on the ingress router.

8:59This is a PE router.

9:02It faces the customer.

9:03Next, we have its opposite counterpoint, the egress LSR.

9:08This is what actually removes the label

9:11as it leaves the MPLS domain.

9:14In other words, when it's heading back to the customer.

9:16That means that this is also a PE router because it is,

9:20in fact, facing the customer.

9:22Finally, we have the intermediate LSR,

9:26which we would also refer to as a core router.

9:29This would be a device that's doing all of its forwarding

9:33based on label switching.

9:35This of course, is the big thing that makes it MPLS.

9:39This would be the P router, or the provider router,

9:43sitting in the provider's core.

9:47Now we just got done mentioning that the egress router is

9:51the one that actually removes the label,

9:53but there's an interesting sort of situation

9:55here, where that forwarding label is often not

9:59necessary on the egress LSR.

10:02The egress LSR already has that needed routing information

10:07to do IP forwarding.

10:09Remember, we said the PE routers still have customer routes.

10:14So they don't need this label.

10:17So then it becomes more efficient to remove that label

10:23before it gets to the egress router.

10:26Now we're going to jump down just a second here,

10:28and the reason for that is because it saves the egress LSR

10:33from doing two lookups that would first

10:36have to look up the label, find out that the label is supposed

10:40to be removed, and then it would still have to look at the IP

10:44forwarding table or the routing table and use IP forwarding.

10:49So if it doesn't need the label, it's

10:52far easier to remove that label on the second-to-last router.

10:58This is referred to as the penultimate router,

11:02or second-to-last router.

11:04This whole concept of removing that label on that router

11:09is called PHP, or penultimate hop popping,

11:15because we're popping the label on the penultimate router,

11:19or the second-to-last router.

11:23And one very key point to this--

11:25its penultimate hop popping.

11:28It's popping a label, not removing the labels.

11:33And I know that almost sounds like the same thing,

11:36but in MPLS, it's not.

11:38When we get into our detailed skills on MPLS,

11:41we're going to find out there's something called a label stack.

11:44There can be more than one label,

11:46and I might still need the other labels,

11:49even on the egress router.

11:52So I'm only popping one label.

11:55That's what pop means.

11:57It means to remove one and only one label, not all of them.

12:02So don't confuse popping a label with unlabeling the traffic.

12:07These are not the same thing.

12:09PHP removes one label, which would commonly

12:13be the forwarding label.

12:15Now all of this said, we do have one more important topic

12:17to cover, but we're going to need some room, so let's clear

12:21this off again.

12:23So one problem we do have with MPLS,

12:27when it comes to scaling to the size of a service provider,

12:30is that MPLS is ultimately still based on the underlying IGP--

12:36so for example, as we have on our diagram here,

12:39OSPF or IS-IS running in these different clouds.

12:43This can cause scalability issues

12:46because each of these environments, as we can see,

12:50are broken into their own label switch paths.

12:54And this means that the end-to-end label switch

12:57path through this environment would, in fact, be broken.

13:01And since a lot of our services rely on this label switch path

13:06to be consistent from end-to-end,

13:09this would be a problem.

13:11So again, because of all of this we're

13:13going to have these islands of IGP domains.

13:17Ultimately, using these islands means

13:20that we break that end-to-end service availability.

13:24This is the problem.

13:26We need an end-to-end label switch path.

13:30The way we do that is through Unified MPLS.

13:34This is a hierarchical model, so sort

13:37of as we're showing on our diagram, where we have access,

13:41aggregation, core, and just for a note,

13:44the routing protocols were showing OSPF 1, 2--

13:48that doesn't really matter, could be of course anything.

13:50It could be IS-IS the whole way across,

13:52could be OSPF the whole way across,

13:55we just put some routing protocols in there.

13:57So the way Unified MPLS accomplishes this,

14:01it uses BGP to exchange the labels between these network

14:06segments.

14:06This is all based on RFC 3107.

14:10This uses end-to-end labels for the final destination.

14:15Now this will be using next-hop-self in BGP

14:19so that the ABRs, these devices here,

14:22will be the next hop for BGP.

14:26That way, the forwarding label is kept within each domain,

14:30but the end-to-end label is consistent.

14:33And when that's all said and done,

14:35it'll look something like this.

14:38We'll end up with an end-to-end, inner domain label switch

14:43path, or LSP.

14:45And this will let us have full end-to-end LSPs to support

14:51our end-to-end services.

14:54In this video, we got just a quick introduction

14:58to MPLS and some of the concepts behind it,

15:02but most importantly, I'm hoping what we really

15:04got out of this is why we want to use it

15:08in the service provider core.

15:10The way it actually functions and gets

15:12all these things done--

15:13that's a big topic that we have whole skills dedicated

15:17to coming up later in the course.

15:19But for now, this was just an introduction to MPLS,

15:23and again, hopefully just really understanding

15:26why this is such a key technology to allow our service

15:30providers today to offer all of the services

15:32that they're able to offer without supporting

15:35a ton of different infrastructures.

15:38I hope this has been informative for you,

15:40and I'd like to thank you for viewing.

0:00[SOUND EFFECTS PLAYING]

0:07So now that we've done an introduction to MPLS,

0:10now let's jump in and get an overview of segment routing.

0:16Segment routing actually builds on top of an MPLS environment,

0:21and it lets us do a very efficient form

0:24of source-based routing.

0:26Now, we can do this for a variety of reasons,

0:29but one of the big reasons is it lets us bring SDN, or Software

0:33Defined Networking, into a service provider environment

0:37where a controller would actually

0:40control our segment routing.

0:42Now, of course, there are other reasons to use this

0:44and we'll look at that again in some future skills

0:48where we're going to really jump in to segment routing.

0:51Just like MPLS, this is just an overview

0:54just so we understand the concept of what this is

0:58and what it can do in our environment.

1:01So as we said during the introduction,

1:04segment routing is a flexible and scalable form

1:08of source routing.

1:10And just in case you're not familiar with source routing,

1:14this simply means that the source specifies

1:17the path that's going to be taken through the network

1:20to reach the destination.

1:22Normally, we route based on the destination

1:26and each router along that path makes its decision

1:30independently on the best way to reach the destination.

1:33So this is a way to explicitly choose

1:36the path from the source.

1:38It does this through a series of labels,

1:41so this builds on top of an existing MPLS infrastructure.

1:47So one of the assumptions going into segment routing

1:50is that we already have an MPLS core.

1:54So this is why we said that it's very, very

1:56common for the service provider core

1:58to, in fact, be MPLS to support these extra features,

2:02such as segment routing.

2:04And one of the other things this brings to the table

2:07is the ability to do Software Defined Networking, or SDN,

2:11inside of a provider's network.

2:15This allows the controller to specify the path.

2:19And again, it would do this from the perspective of the source.

2:22One example of this is the IOS XR Transport Controller,

2:28or the XTC.

2:30Now, this is a separately-licensed product

2:32that actually runs on top of IOS XR.

2:36This is not something we're going to be focusing

2:38on a lot in this course.

2:39But just so you're aware, this is

2:41a product that's available as a segment routing controller.

2:46So again, ultimately, the way this works is we

2:49have a list of segments which are denoted by labels that

2:53tells it which segments to traverse

2:56as the traffic moves from the source to the destination

3:00through our network.

3:02So let's talk a little bit more about the segments

3:05that we're going to be using to forward our traffic

3:07through the network.

3:09So the first thing to note is that these

3:11can be either local or global.

3:14Local, of course, would mean just to the local router

3:18and then global would mean it's reachable through the entire

3:22segment routing environment.

3:24Each one of these segments is identified by a segment

3:28identifier, or an SID.

3:30This SID is going to be pulled from the segment routing

3:35global block, or the SRGB.

3:38This SRGB is simply a range of labels in our MPLS label range

3:45that's going to be dedicated for segment routing,

3:48so nothing else will use these.

3:50These are dedicated for segment routing only.

3:54These segment IDs do, in fact, come in two forms.

3:58We have the node segment ID, which

4:01identifies the router itself.

4:04This segment ID does have to be manually assigned

4:07by the administrator.

4:09This is to identify the router itself.

4:11It's much like a router ID in pretty much

4:15any other routing protocol.

4:17Then there's the adjacency segment ID.

4:20This identifies the link itself.

4:23Now, this can be either manually or automatically assigned.

4:27Normally, we would allow this to be automatically assigned

4:30by our routing protocol.

4:32These SIDs are then used to specify that path

4:36through the network.

4:38That's what segment routing is all about,

4:40is actually specifying the path that the traffic

4:43is going to take through the environment.

4:46Now, the labels are going to be used by segment routing

4:49to identify these segments and to specify

4:52the path through the network are, of course,

4:54going to have to be exchanged between the routers.

4:57Now, in the case of just, say for example, regular IP

5:00forwarding, we would do this with LDP,

5:04or label distribution protocol.

5:06But in the case of segment routing,

5:08we're going to call upon our IGPs.

5:11So this uses the IGP to exchange these labels.

5:16Both OSPF and IS-IS have been updated to support SR,

5:23so these both fully support segment routing.

5:26And this essentially means that LDP is not really required

5:30in this environment, because it's

5:32using the IGP instead of a dedicated label protocol,

5:35such as LDP.

5:39And, of course, this can be incredibly useful for migration

5:43or, if we buy one company and the other company

5:46doesn't support this, that these can, in fact, coexist.

5:51So we can run segment routing and traditional IGP/LDP-based

5:56MPLS, in other words, traditional MPLS,

6:00at the same time with no issues.

6:03Since we're using this SRGB, the labels for traditional MPLS

6:10and the labels for segment routing will never mix.

6:14So there's no reason these can't coexist at the same time.

6:18It'll simply just switch the traffic right

6:20through with no problem.

6:23In this video, we took a quick look at segment routing.

6:27This is basically, again, a form of source routing

6:31where the source device specifies

6:33the path that's to be taken through the network.

6:36We looked at the different types of segments that

6:38are used by segment routing.

6:40And we also looked at how the labels that

6:43are going to be used for this in MPLS are, first off, reserved

6:49and they're taken out of that global block

6:51and they're exchanged by the IGP rather than

6:55having some dedicated protocol, such as LDP.

6:59I hope this has been informative for you,

7:01and I'd like to thank you for viewing.

0:07Now it's time to jump in and look at some of the transport

0:10technologies that are implemented

0:13in many different service providers.

0:15Now these days, a lot of things are

0:18moving to straight Ethernet.

0:20However, for a lot of long haul connections,

0:22we do still need some of these other technologies.

0:25We also use them sometimes to help us

0:28with other features such as super high speed failover,

0:31although we do have solutions in Ethernet to handle those things

0:35these days as well.

0:36But let's jump in and talk about some

0:38of these technologies that are very common in a service

0:41provider network.

0:43So the first technology we're going to take a look at

0:46is SONET and SDH.

0:49Both of these are based on synchronous TDM, or time

0:53division multiplexing, and the standard for this

0:57describes the frame format to be used.

1:01Speeds for this generally range from 52 megabits

1:04per second up to, currently, 40 gigabits per second.

1:08And just as a note, these are very similar technologies.

1:13However, SONET is more based in the US, where

1:17SDH is more common in Europe.

1:21One of the big advantages to SONET

1:23is it does operate in a ring topology

1:26so that if one ring in the SONET environment fails,

1:30it can failover very quickly to the other ring.

1:33So this generally has a less than 50

1:37millisecond failure time for this to detect a failure

1:41and switch to the other ring.

1:42In other words, it's very good at fault tolerance.

1:46The next one we're going to look at

1:48is DWDM, which is our dense wave division multiplexing.

1:53And if anybody's not familiar with the idea of multiplexing,

1:57essentially what we're doing is we're

1:59taking multiple OC signals, which is your optical carriers,

2:04and we're sending them over a single optical fiber.

2:08The way this is done is think of it

2:11like there's a prism at each end.

2:14Between these two prisms, we're sending our combined signal,

2:18and then on each end, that signal

2:21is being broken out into different wavelengths,

2:25each of these wavelengths representing

2:28a different signal, potentially a different signal

2:31from a different customer.

2:32But this is the whole idea behind any form

2:36of multiplexing, that we're sending multiple signals

2:39over the same single cable.

2:41And in the case of DWDM, we're doing this again

2:44by different wavelengths of light, and just for reference,

2:48this does use the 1550 nanometer band.

2:51So by using these different wavelengths,

2:54we can get multiple signals through a single cable.

2:57Next up is your reconfigurable optical add/drop multiplexing.

3:02Now what this does is this effectively

3:06allows us to change these prisms and remove a signal.

3:10So say, for example, we wanted to get rid of the red signal.

3:14We could get rid of the red signal

3:16without interrupting the other signals.

3:20That's the important part here, that they

3:22can be dropped or added without having

3:26to convert the entire signal back to electrical,

3:31and then add or drop the signal, and then convert it

3:34back to optical again.

3:35Before we had this technology, that's what we had to do.

3:39We didn't have a way of adding or removing wavelengths

3:43from the signal without changing it back to electrical.

3:47And since we're not changing it back to electrical,

3:49this also allows us to make these changes without affecting

3:54the other through channels.

3:56So for example, in my diagram, the yellow, the green,

3:58the blue were not affected.

4:00And if we wanted, we could, of course, add the red right back

4:04in, and we'd be right back where we started without interrupting

4:08any of the other signals.

4:09Next up is CES, or circuit emulation service.

4:13I personally haven't seen this technology for quite some time.

4:16This was generally used to transfer voice and video

4:20over ATM, and, again, I haven't seen ATM in use a whole lot

4:27in current service provider networks.

4:29Most ATM in the environments that I have seen

4:32has been removed at this point.

4:36Up next, we have TDM over IP, and the idea behind this

4:41is to be able to carry--

4:43sort of legacy now--

4:44T1/E1, or T3/E3 connections over a packet switch network--

4:52in other words, an IP network.

4:54This is a nice feature if a service provider is also,

4:58of course, supporting these older circuits,

5:00and they want to move to an IP solution

5:03but still support customers that are still

5:05on these older circuits.

5:08Now things certainly aren't the same everywhere

5:11and wherever you live and work might be completely different.

5:15But in my experience with service providers in my area,

5:18and that I've worked with across the United States anyway,

5:22these are pretty much gone.

5:24We don't really support E1s/T1s, E3s/T3s, and even

5:29legacy customers that have had these

5:31for a really long time have actually

5:33been told to migrate off of them and they

5:36won't be supported anymore.

5:37So I really don't think you're going

5:39to run into too many customers you need to support

5:41with these features, and I don't think

5:43most service providers will even support them anymore anyway.

5:47But just in case you do, it's always

5:50good to know what they are.

5:51Next up is IP over DWDM, which is simply putting the DWDM,

5:57the dense wave division multiplexing, directly

6:00into the routers.

6:01So before this, we would have the DWDM switches,

6:05the routers would run Ethernet into those switches, and then

6:08DWDM for the long haul.

6:10Now we can bring the DWDM directly into the routers.

6:14Now the most common thing we're using today

6:16is carrier Ethernet, or CE.

6:19Currently this gives us speeds up to 400 gigabits per second.

6:24Of course, this number is going up all the time

6:26as newer equipment comes out, so always check with Cisco to see

6:30what the latest offerings are.

6:32But this gives us great scalability, great reliability.

6:36We can bring services into this such as QoS.

6:39We have service management.

6:41Some of these things we'll see little bit more in this skill.

6:45We have standardized services, and just quite

6:48honestly, to add one more thing to this list,

6:51most network engineers are very familiar with Ethernet,

6:54making this a real easy technology to support.

6:58Now when we need to get Ethernet over the long haul,

7:01well then, we have some choices.

7:03So to transport this Ethernet, if it's not going

7:06to go over Ethernet itself--

7:08in other words, standard Ethernet carriers--

7:11we can in fact run Ethernet over SONET or SDH.

7:15We can, of course, run it directly over DWDM,

7:19over fiber natively, or we can run Ethernet over MPLS.

7:23But we have a lot of choices when

7:25it comes to supporting Ethernet in our service provider

7:28environment.

7:29Now just to summarize here, the most common implementation

7:34in most service providers today would

7:37to be running IP over MPLS, with the MPLS running over Ethernet.

7:45In this video, we just took a quick look

7:48at some of the transports that it

7:50would be quite common to see inside of a service provider

7:53environment.

7:54Keep in mind that most of our environments

7:56today will, in fact, just be running

7:59IP over MPLS, maybe encapsulated or doing traffic engineering,

8:05VPN, and that sort of thing, but still

8:07basically carrying IP and IPv6 over MPLS over an Ethernet

8:14underlay.

8:15Now that Ethernet may also be running over something else,

8:18like DWDM or SONET, but that's the basic model

8:22that we see in most service providers today.

8:25I hope this has been informative for you,

8:27and I'd like to thank you for viewing.

0:00So, in the previous video, we got an introduction to the topic of DWDM or Dense

0:09Wave-length

0:10Division Multiplexing.

0:12However, in SP Core 1.1, Cisco has broken this out to be its own separate topic

0:21, not

0:21just included with other transport technologies.

0:25So, as such, we should jump in and get a little bit more detail on DWDM, its

0:31capabilities,

0:33its advantages and disadvantages, and we'll take a look at some use cases and

0:38products

0:39that can actually use DWDM.

0:41So, all of that said, let's jump in and take a look at DWDM in some greater

0:47detail.

0:48So, let's begin our discussion of DWDM by talking about some of its key

0:55features.

0:56So, the first thing, of course, and the most important thing we're after here

1:00is that

1:01it has a very, very high capacity.

1:04The way, of course, we accomplished this as we discussed earlier is that we're

1:09going

1:09to take many channels on most of today's hardware.

1:13It's around 128 channels, this, of course, varies a lot from vendor to vendor,

1:18but we're

1:19going to take all these different channels and we're going to send them across

1:23a single

1:24fiber optic cable.

1:26Each of these channels can then operate anywhere from 10 gigabit per second up

1:31to 400 gigabit

1:33per second, and most of the interfaces available on the market today are in the

1:38400 gigabit

1:39per second range.

1:41Now, again, we always want to say things like, "or more," and "up," because, of

1:46course,

1:46this technology is changing all the time, and these are fairly accurate numbers

1:52for the

1:52time of this recording, but, of course, this is going to change in the future

1:57as the technology

1:58improves.

1:59Of course, the main thing we're after here is this efficient bandwidth

2:04utilization.

2:05That's how we're getting this higher capacity.

2:09We're going to take that optical spectrum and we're going to use very dense

2:14spacing in

2:15the different wavelengths in order to get as many channels as we can out of the

2:20existing

2:21fiber.

2:22And, again, that's why we say as the technology improves, we'll get more

2:26channels and we'll

2:27get more throughput on that same channel.

2:31Of course, another key feature here is going to be scalability.

2:35Now, what we're saying here is that we can add more wavelengths as needed, but

2:41keep in

2:41mind that is, of course, going to be limited by whatever our hardware can

2:46handle.

2:46So, there's sort of an assumption with this statement that maybe we're not

2:50using all of

2:51the wavelengths at first, and then scalability we can add more as we go.

2:56There's, of course, also the possibility that when we hit all of the "and ups"

3:01and "or

3:02"and we do equipment refreshes," well, then we can possibly add more

3:07wavelengths there

3:08as well as the technology changes and/or, again, we replace equipment.

3:14So there's several different ways that the scalability could come into play,

3:17but the

3:18cool thing is we can add and remove wavelengths on existing equipment without

3:23actually disrupting

3:24traffic.

3:26Another big advantage, of course, is the versatility of DWDM.

3:31It can simultaneously carry, which is actually pretty cool.

3:36In other words, it can handle these things at the same time.

3:40It can actually handle things such as Ethernet or Sonnet, SDH.

3:48Remember that Sonnet is our synchronous optical networking, and SDH is synchron

3:53ous digital

3:54hierarchy, and it can carry storage protocols as well, such as fiber channel.

4:00Now, that's not going to be such a common thing to do these days.

4:03We have other choices for storage, but it can certainly be used for that type

4:07of application.

4:09Next, let's talk a little bit here about how DWDM actually works.

4:15So let's start by bringing up a diagram here where we're showing our ingress

4:20side over here

4:20on the left and the egress side over here on the right.

4:24So the traffic is going to be flowing from left to right in our discussion here

4:29, and

4:29keep in mind that this exact same thing would simply be happening the other

4:34direction.

4:35So we can see just from a general idea here that we have multiple signals

4:39coming in over

4:40here on the left, and those same signals are coming out over here on the right.

4:46So let's talk a little bit more about how this actually functions.

4:50So the first step, of course, is that the data streams come in and they're mod

4:55ulated

4:56into these separate wavelengths.

4:59That's, of course, what's being denoted here with these different signals

5:03coming in and

5:04the different wavelength signals that are being used on specific frequencies.

5:09Now, as we mentioned earlier, this does in fact use the C band 1530 nanometers

5:17to 1565

5:18nanometers.

5:19This is the transmission window.

5:22So step one, we separate all of these things into different wavelengths.

5:27Step two, we then combine all of these signals at the multiplexer.

5:33So on the ingress side, that's going to be this device right here.

5:37And this could be a piece of hardware.

5:39That's how we've done it traditionally.

5:41However, we also have D W DM interfaces and SFPs and such for our routers and

5:47switches

5:48now.

5:49So we can do this right in the routers and switches.

5:52Now, again, the main idea is the functionality.

5:56It is still a multiplexer because we're taking multiple signals that we have

6:01over here and

6:02combining them into a single signal that we're going to be sending across this

6:07single fiber

6:09between the multiplexer and the D multiplexer.

6:13So again, the next step would be to actually transmit this out over the fiber.

6:18So as we said, we combine the signal and it's sent out over the fiber.

6:24Now that's going over this single fiber here in the middle.

6:28During this transmission, we of course have to worry about signal strength and

6:32the signal

6:33strength can of course be adjusted on a lot of our multiplexers.

6:38So depending on the signal strength and the distance, we may actually have to

6:43do amplification

6:44somewhere here in the middle of the transmission.

6:47So we can use optical amplifiers like an EVFA and we can use this to maintain

6:53the signal

6:54strength to go the distance that we need to.

6:58Then of course, our final step is on the receiving side.

7:02This of course is going to come into the D multiplexer or the DMox and the DMox

7:08is going

7:09to then separate those signals back into the individual signals to match what

7:15was sent.

7:16And hence, in this example, we have signal one comes out as signal one, signal

7:21two comes

7:22out as signal two and so on.

7:25So each of these signals are all being carried again in this single piece of

7:30fiber between

7:31the multiplexer and the DMox.

7:34So just to put all of this together, let's just talk about some of the

7:38advantages here

7:39of DWD now that we really understand what it's doing.

7:43So first of course, this is going to give us a massive data transport.

7:49What we're doing is we're taking existing infrastructure and that's what's so

7:53awesome

7:53about this is we're increasing the capacity of something that's already there.

8:00So yes, of course, there's going to be possibly hardware purchases at the end

8:04points.

8:05However, the transmission lines, the optical lines that have already been laid

8:10between

8:10geographical locations are still going to be used.

8:14So that is a huge factor of DWD.

8:18Anytime we can get more usage or increased capacity out of something that

8:24already exists,

8:26that's of course going to be a really, really good thing.

8:29Hence the next point that it's very, very cost efficient.

8:34For the reasons we just said, we don't have to lay any additional fiber because

8:39we're

8:39using existing fiber.

8:42That's a huge factor.

8:44This is probably of course one of the most important aspects of wide area links

8:49.

8:50Laying physical cables in the real world costs a lot of money.

8:54So I can't overemphasize how important it is that we're using existing

8:58infrastructure.

9:00That of course minimizes the infrastructure costs because again, we might need

9:05to replace

9:05the endpoints.

9:07So we say minimize, right?

9:09We're not saying that it eliminates infrastructure costs because again, the end

9:13devices may need

9:14to be updated new interfaces, new QSFPs, things like this.

9:19But at the end of the day, not having to lay new lines is huge.

9:26And of course, another huge factor here for us as service providers is that it

9:30is in fact

9:31protocol agnostic.

9:33We already said that we can support multiple data formats.

9:37Even going back to things like ATM and frame relay can be sent over this.

9:42Again, I'm not sure how important that is to most service providers today.

9:46But the point is we can support all sorts of things over this because this is

9:51acting

9:51more as just an optical transport.

9:54What we're running on top of it becomes less of an issue.

9:59And of particular importance to service providers is going to be that long

10:03distance transmission.

10:04Again, particularly if we start using optical amplifiers, this can cover very

10:10long distances.

10:11But even just some of the regular interfaces on Cisco routers can handle up to

10:161500 kilometers.

10:18So that's still a pretty good distance even without optical amplifiers.

10:23So again, long distance, very important here.

10:26And naturally, along with the fact that we're using fiber is the fact that we

10:31have low latency.

10:33So we're going to get high speed, low latency, kind of activity, always an

10:37important factor.

10:39And of course, this is something that really any sort of optical interface is

10:43usually very

10:44good at.

10:45Now, one of the key factors to keep it low latency, though, of course, is to

10:48keep as much

10:49hardware out of the path as we can.

10:52This is why doing things like bringing the DWDM interfaces into the routers is

10:57going

10:58to be the most efficient way to do this wherever possible.

11:02So finally, let's wrap up here by talking about some of the use cases for DWDM.

11:09Why is this so important?

11:10Why do we care so much aside, of course, from the clear advantages?

11:14But how do we take those advantages and make them work for us?

11:17Now from a service provider's perspective, one of the most important things is

11:22going

11:22to be for telecommunications.

11:24We're going to want this for our backbones and our long haul communication

11:29links.

11:30These are the links across countries, across continents, between countries, all

11:34around

11:34the world.

11:35This is where things like DWDM are going to be a spectacular solution for a

11:41service provider.

11:43However, this is not just good for service providers.

11:47This is also going to be very useful for enterprise networks, for things like

11:52DCIs or

11:52data center interconnects.

11:54This is where they have two separate physical locations for their data centers.

11:59Of course, data centers are going to need very, very high capacity between them

12:04.

12:04And that's a perfect case for DWDM.

12:08We can throw a link in there between the data centers as the DCI and get that

12:12high speed,

12:13low latency, high throughput over the fiber links.

12:17Sort of along the same lines as data centers, we have cloud connectivity.

12:24Again, linking probably data centers to various cloud providers, particularly

12:29for companies

12:29using a hybrid type network, where some of their stuff is in the cloud, some of

12:34their

12:34stuff is housed in their own local data center.

12:38This is going to be a great feature because again, we need those things to

12:41communicate

12:42quickly, just like we did up here for our disconnected data centers.

12:48It's just in this case, one of them happens to be in the cloud.

12:51Nobody else who's very concerned about things like latency, by the way, would

12:56be things

12:57like financial services, high speed trading networks.

13:01You have to understand that they measure things in terms of microseconds.

13:06We normally refer to delay on networks in the terms of milliseconds, but that's

13:11too

13:12slow for high speed trading.

13:14Hence, where they say here, ultra low latency.

13:18In fact, Cisco has a couple switches, one in the Nexus product line.

13:23I think there's one in the catalyst product line as well, that are designed and

13:27built,

13:28particularly for financial services.

13:31The entire focus of that platform is port to port latency.

13:36It doesn't have a lot of features, but these are the fastest switches moving a

13:41packet from

13:41one port to another.

13:43Again, it's all about high speed delivery.

13:47And someplace else where this could be useful would be content delivery

13:51providers.

13:52So think of things like YouTube, Netflix, Hulu, pick your favorite streaming

13:57content

13:58provider.

13:59These guys need very, very high bandwidth links because they could potentially

14:05have hundreds

14:06of thousands, possibly even millions of viewers at the same time.

14:11And yes, they have, you know, the large ones have data centers all over the

14:16world.

14:16So you are, of course, pulling videos off the local servers.

14:20It's not all going to one data center.

14:22But nonetheless, those data centers do have to be able to handle a lot of

14:26people trying

14:27to stream videos at the same time.

14:30So this is going to be another good place for a very high speed link with very

14:35low latency.

14:37So in this video, we jumped in and got a little bit more detail on DWDM.

14:43We talked a little bit more of its advantages.

14:45Didn't really have any disadvantages because honestly, this particular

14:49technology doesn't

14:50really have any.

14:52We're getting more bandwidth out of the same connections.

14:55There's really not a downside to this.

14:58Possibly you could say that the need to purchase new endpoint equipment, maybe

15:02that's the disadvantage.

15:04But other than that, this is pretty much all just upside.

15:08So that said, hopefully you learned a lot here about DWDM and we'll see you in

15:13the next

15:14video.

15:14[BLANK_AUDIO]

0:00So now let's take just a few minutes to go through Cisco's current product

0:07offerings

0:08in the DWDM space.

0:11Now keep this in mind, every time we're looking at hardware that's only going

0:16to be current

0:17at the time of this recording.

0:19And this is not going to be an extensive list with all the details of all the

0:24hardware.

0:25Below, I have a link to a document which is sort of like an overall document

0:30that then

0:31has links to each of the different types of interfaces and their data sheets.

0:36There'll of course be a lot more information there.

0:39This is meant just to be an overview of the most popular offerings that Cisco

0:43currently

0:44has in their portfolio.

0:46So that said, let's jump in and take a look at some of the more popular DWDM

0:52offerings.

0:53So let's begin by taking a look at the DWD transceivers.

0:58These are actually pluggable modules that can be added to various routers and

1:04switches.

1:04Again, keep in mind that each SFP is going to be compatible with certain

1:09platforms.

1:11So let's go down our little list here.

1:13We have the DWM SFP plus.

1:16This is a 10 gig module.

1:18It supports up to 80 kilometers of transmission distance and this will work

1:23with Sonnet and

1:24SDH as well as Ethernet and optical transport networks.

1:30So again, it can support multiple different protocols.

1:34There's also an XFP.

1:36This is also a 10 gig offering.

1:39And as we can see here, this is actually very similar to the SFP plus.

1:43We just talked about here.

1:45It's just a little bit of an older form factor to fit in some of the older

1:49devices.

1:50This does support the full C band of DWDM channels.

1:55Then we have our high speed offering, the QSFP 28.

2:00This is offered in both 100 and 400 gig.

2:04These are coherent optics and these are really for high capacity metro and long

2:10haul networks.

2:11Some of the examples here, we have the QSFP 100 ZR4.

2:17This is the 100 gig offering and then the 400 gig ZR and ZR plus, which are of

2:23course,

2:24the 400 gig offerings.

2:26Next, let's talk about the various different coherent interfaces that are

2:31available.

2:32These are both pluggable and fixed depending on exactly which model we're

2:35talking about

2:36here.

2:37But these are for ultra long haul and very high capacity networks.

2:43So this would be the CFP2 DCO.

2:46This is available in 100 gig and 200 gig.

2:50Again, this is specifically for long haul DWDM.

2:55This works with the Cisco NCS and ASR platforms.

3:00Then of course, there's the 400 gig ZR and ZR plus.

3:05This is the one we just talked about a moment ago, but it also falls into this

3:09category

3:09as a coherent DWDM interface.

3:13This one is specifically designed for data center interconnects.

3:17And this is compatible with open Rotem and standard DWDM grids.

3:24Next up, we have various line cards that are available for the routers and

3:29switches.

3:30These again are going to provide native DWDM support.

3:34So we have the NCS 1000, 2000 and 4000 solutions.

3:40These are multi rate DWDM transports meant for core and metro networks.

3:46Once again, we support Rotem.

3:48We support OTN and that multi rate we again support 100 to 400 gig.

3:55There's also the ASR 9000, the Cisco 8000 series line cards.

4:01These are high density DWDM cards, mostly meant again for service providers and

4:07enterprise

4:08core networks.

4:10And finally, let's talk about OTN and Rotem solutions specifically.

4:15Now, again, some of the things we already covered will also do these, but these

4:19are specific

4:20solutions.

4:21So these are very specific OTN switches and Rotems.

4:27Finally, we have that NCS 2000, which is specifically a Rotem.

4:31This supports dynamic optical wavelength switching.

4:36And for the optics in this, you can use the CFP2 DCO that we discussed or the Q

4:42SFPDDDWM

4:44optics.

4:45We also have the ONS 15454 MSTP.

4:50This is a multi service transport platform.

4:54This specifically is for DWM and Sonnet.

4:59So in this video, we just jumped in for a few moments here to discuss some of

5:02the current

5:03offerings in the Cisco product line that support DWDM.

5:08[BLANK_AUDIO]

0:00Next up, let's talk about routed optical networks or RONs or RONs.

0:09Now technically there is no acronym for routed optical networking.

0:14However, it is a term that's thrown around fairly commonly, just so you're

0:18aware.

0:19But either way, in this video, we want to jump in and get an introduction to

0:23routed optical

0:25networks.

0:26What are they?

0:27What does this actually mean?

0:29What are the benefits, advantages?

0:30Are there any disadvantages?

0:32But in a nutshell, the basic idea is we're going to take the optics, which we

0:38use for

0:38things like DWDM, that sort of thing, and we're going to bring those optics

0:43directly

0:44into the devices that are also doing the IP routing.

0:48So we're going to be sending our IP directly over things like DWDM.

0:53So what we're doing is we're consolidating the devices and the technology, and

0:57therefore

0:57simplifying the whole process.

1:00Now all of that said, let's jump in and take a look at some more details.

1:06So let's begin our discussion by talking about some of the advantages of our

1:11routed optical

1:11networks, starting with simplified network management.

1:16This is of course going to be key.

1:19Simplified network management clearly means that we're going to need less time,

1:23effort,

1:24and personnel hours in order to manage our network.

1:28And of course, the reason for this is overall if we bring the optics into the

1:33routed device,

1:34we're going to have fewer devices and fewer layers that actually have to be

1:40managed.

1:41So rather than having to manage an optical device and a routing device, those

1:46now become

1:47the same thing.

1:48So that's of course going to simplify our entire network management.

1:53It's also going to improve performance.

1:56Anytime we don't have to have more devices involved, that is going to increase

2:01performance.

2:02So again, we're going for this direct IP over optical structure.

2:07This is going to reduce the latency and it's going to increase the throughput.

2:12Of course, less devices in the traffic path is going to increase performance.

2:17It's less devices that have to handle the traffic.

2:21We're also going to get rapid service delivery.

2:25This is coming from the fact that we're generally going to be using automation.

2:29And this enables quicker provisioning and of course, better adaptability to

2:34changing

2:34demands.

2:35So if throughput's changed or we start getting congestion on one interface, we

2:39can move traffic

2:40to another one and so on.

2:42So automation is going to aid us here not only with the quicker provisioning,

2:46but also

2:47that adaptability as things on our network change.

2:51And of course, as always, the big one here is we're going to have reduced costs

2:57.

2:57Why?

2:58Well, there's a couple reasons here, right?

3:00One of them we've already talked about.

3:02If we have simplified network management, that is going to lower our operating

3:07expenses.

3:08So that's of course going to make things cheaper.

3:10However, we also don't need all of this.

3:14Here we're calling it redundant equipment.

3:16I'm not necessarily sure redundant is the best word here.

3:20That's how Cisco refers to it.

3:22We're still going to want redundant equipment.

3:24We want redundancy in our network.

3:27By redundant, I think what they mean is multiple pieces in the path doing sort

3:31of the same

3:32thing or doing things that need to be done, but not doing it all in one device.

3:38So maybe not necessarily redundant so much as additional equipment.

3:42So of course, also having less equipment there is going to reduce that

3:46operational complexity

3:48as we mentioned above under the simplified network management.

3:51All of these things, of course, tie together to bring us that reduced cost.

3:57Next up, let's talk about some of the key features.

4:00Again, we've already sort of talked about the general idea.

4:03We're going to bring everything together.

4:05But what we're referring to here is specifically the consolidation of layers.

4:11We're going to take those optical transponders and we're going to put them

4:15right into the

4:15routers.

4:17And what this is going to do is, of course, consolidate the network layers into

4:21a simpler

4:22architecture.

4:23So rather than having one device handle layer one, one handle layer two, one

4:28handle layer

4:29three, we're putting all of this into one single device in the routed optical

4:34network.

4:35Then we're going to use that device with the consolidated layers to implement

4:40IP over

4:40DWDM.

4:42Now, as we've mentioned previously in the course, DWDM is the technology that

4:48allows multiple

4:49data streams to be sent over the same optical fiber.

4:53So it's multiplexing the data, multiple streams using different wavelengths of

5:00light.

5:00This of course allows us to get much more data through the same optical cable.

5:06Now with IP over DWDM in our routed optical network, the IP routers then

5:12directly interface

5:14with those DWDM systems because they have the interfaces right in the router.

5:21This of course is going to eliminate any intermediary equipment like we used to

5:26have.

5:27So things like our DWDM, multiplexers and demuxes, demultiplexers, those used

5:33to be separate

5:33pieces of equipment, now we're bringing them right into the routers and letting

5:38the IP

5:38traffic go directly over those interfaces.

5:42Now we already sort of mentioned automation and like most things in networking

5:47these days,

5:49routed optical networks are moving towards automation and software control

5:54using software

5:55defined networking or SDN.

5:58And this is going to automate really the entire process, but it automates

6:02specifically

6:03your provisioning.

6:05So as you're rolling out new equipment, you can do this fully automated using

6:10SDN.

6:10It also of course takes care of monitoring and can alert us of course of any

6:15problems

6:15and troubleshooting.

6:17Now keep in mind, it's not listed here specifically or separately, but

6:22configuration management

6:24and ongoing maintenance is sort of wrapped up here in the provisioning.

6:29So that's just not going to be putting on like your initial configuration and

6:32that sort

6:33of thing, but ongoing update.

6:36So maintenance, things like that, policy changes, all of this is going to be

6:41automated through

6:42SDN.

6:43Of course, a huge advantage to this is it's going to give us much, much faster

6:47deployment,

6:48which we mentioned earlier, and it's going to reduce human intervention.

6:53The big advantage to that of course, when we say reduce human intervention, it

6:58's sort

6:58of a polite way of saying reduce human error.

7:02Humans are of course prone to errors and letting software to find networking or

7:08SDN handle

7:09all of these processes is really going to remove that factor of human

7:14intervention from

7:15the route optical network environment.

7:18Of course, another huge feature that we have here is cost efficiency.

7:23Again, if we're reducing the amount of hardware, again, we don't have

7:29standalone transponders,

7:31like we mentioned a few minutes ago, all of this is in the router itself.

7:36It's going to be less hardware to purchase.

7:38Now of course, if we have to replace existing hardware to do route it optical

7:43networking,

7:43well, that might be of course a cost that we have to endure.

7:48However, we'll usually do this around the time that we need to do an equipment

7:52replacement

7:53anyway.

7:55As we've mentioned before, this also simplifies the operations.

7:59We don't have as many devices.

8:01We don't have as many devices to maintain.

8:04And keep in mind too, it's not just about the hardware.

8:08All of this hardware that we're not having to have now would normally have to

8:13have things

8:14like support contracts.

8:16It's got to be powered.

8:18It's got to be cooled.

8:19It has to have real estate or a data center or a closet, something to sit in.

8:24So there's a lot more expenses involved here than just the actual piece of

8:28hardware itself.

8:30There's all the things that go along with that.

8:32So when you eliminate all of those things, you are definitely lowering your

8:37capital expenditures

8:39for sure because you're putting out less money.

8:42You're not buying these standalone transponders over here.

8:46It's less equipment to purchase.

8:49Now you'll be purchasing for example, a different type of interface for your

8:54router than you

8:55would if it was just say, for example, an ethernet interface.

8:58And that other interface may actually be more expensive.

9:02However, it's not going to be more expensive than a whole other piece of

9:06equipment like

9:07we would have had traditionally.

9:09And of course, the simplifies operations.

9:13So this part right here is really what's going to save us on our op-ex or our

9:17operational

9:18expenditures on an ongoing basis.

9:22Again, it's less service contracts.

9:25We most likely need less personnel to keep up with all of the maintenance and

9:30ongoing

9:30network changes.

9:32So there's a lot of things to contribute here that are going to lower the

9:35operational

9:36expenditures, not even including those other little things I mentioned already,

9:42such as

9:42power, cooling and real estate to put the routers in.

9:47So this is going to save us a lot of money by having less equipment.

9:52Another key feature is scalability and flexibility.

9:57One of the big things we need to be able to do is change our networks on the

10:02fly as things

10:03change.

10:04So not only does it allow us to easily add capacity as we need to, but it makes

10:11it easier

10:12to do things like rerouting traffic based on demand.

10:16As I mentioned a few minutes ago, if a particular circuit gets busy, we can

10:21start sending other

10:22traffic down other circuits, things like that.

10:25And all of this is coming from that SDN, the software-defined networking that

10:30allows us

10:31to again, not only provision quickly, which would be the adding capacity part

10:36of this,

10:37but also reroute traffic on demand based on traffic load.

10:43So there's a lot of advantages to bringing software-defined networking into the

10:48equation.

10:48And I did sort of already mention this one under cost efficiency, but it

10:52probably is

10:53important enough to discuss as its own separate point here, we are also going

10:58to have energy

10:58efficiency.

10:59Again, that simplified architecture is going to consume much less power, less

11:06power, not

11:07only saves us money in the long run, but it's also a greener solution.

11:12We're using less power, less power needs to be generated, and therefore, less

11:17harm to

11:18the environment.

11:19So overall, these are a lot of great features that we get with routed optical

11:25networks.

11:26So just to wrap up, let's talk a little bit here about a few use cases.

11:30Of course, one of the big ones for enterprise networks would be high capacity

11:36data centers

11:37and connecting to cloud services.

11:40So data centers would normally be talking about customer on-prem equipment, and

11:45of course,

11:46cloud services would be services in the cloud.

11:49How does routed optical networks come into this?

11:52Well, this is really going to be for the DCI, the data center interconnect.

11:57So if you have two physically diverse data centers, they need to be able to

12:01talk to each

12:01other at high speed.

12:04And this is where optical networking is going to be a huge advantage.

12:08Whether it's between two data centers that are on-prem for the customer, or

12:13maybe it's

12:13between a customer's data center and their cloud services, those are going to

12:18probably

12:18need to talk to each other as well.

12:20So for any of these use cases, this is going to be a good fit for enterprise

12:25networks.

12:26And of course, for telecommunication services, which is what we're talking

12:30about here, service

12:32providers, we want to optimize those backbone networks.

12:37Links across the country, between countries, across continents, and around the

12:42world.

12:43We need to have good optimized networking and routed optical networks fits

12:49right in here

12:50for where we're trying to go with backbone networks.

12:54We just want more use case to wrap this up.

12:57Enterprise networks, maybe they don't have a DCI or cloud services, but maybe

13:02they just

13:02need high performance wide area networks, just traditional WAM links.

13:08As service providers, we need to be able to provide them with these high

13:12performance links

13:13and routed optical networking may just be the best way to do that.

13:19So in this video, we jumped in and got an introduction to routed optical

13:25networks.

13:26What makes this different from traditional optical networking is we're taking

13:30the optical

13:31interfaces and instead of having a separate transceiver or muxer, demuxer,

13:37multiplexer,

13:38demultiplexer, whatever we want to call it, rather than having separate

13:42equipment taking

13:43care of the optics and then a separate router taking care of the IP networking,

13:49we're bringing

13:49those optical interfaces into the routers and letting the IP go directly over

13:56the DWDM,

13:57saving a lot of equipment.

13:59And when we save that equipment, don't forget that's going to lower both our

14:03capital expenditures

14:04and our operational expenditures because we need to buy less equipment.

14:08We're going to probably need less personnel.

14:11We're going to need less power.

14:12We're going to need less cooling.

14:14We're going to have to buy less support contracts.

14:16So there's a lot of things here that are going to save them a lot of money by

14:20simplifying

14:21the network using routed optical networking.

14:25[BLANK_AUDIO]

0:00So now that we have a good understanding of what a routed optical network is,

0:07let's spend

0:08some time here going through step by step, feature by feature, and comparing

0:12that to a

0:13traditional network.

0:15The big advantage to this, of course, is the better you understand the

0:18differences, the

0:19better you're going to understand the routed optical networks.

0:22So let's go ahead and jump in, take a look at this sort of feature by feature

0:27and do

0:27a comparison of traditional networking versus our routed optical networks.

0:35So let's start off by talking about architecture and we'll start with the

0:40traditional service

0:42provider network.

0:43So the first thing we know about the traditional network is this, of course,

0:48was a layered design.

0:50We had IP or MPLS routing would have been our layer three environment or MPLS

0:56is often

0:56referred to as layer two and a half.

0:59We would have had our optical transport.

1:01We would have had intermediate layers such as sonnet or SDH.

1:06Of course, there's some other choices in there as well.

1:09But the point is these all would have been handled separately, managed

1:14separately, and

1:15implemented separately.

1:17That means that each one of these is going to require standalone devices.

1:22We would have had, of course, our IP routers.

1:25We would have had optical transponders.

1:28And if we needed signal boosting along the way, we would have had amplifiers as

1:33well.

1:34So a lot of different pieces of equipment here that we would have in our

1:37traditional

1:38network.

1:40And that, of course, means that all of these pieces of equipment also had to be

1:44interconnected.

1:45So we would have complex interconnections.

1:49Again, the IP routers had to connect to those optical transport systems by some

1:55sort of intermediate

1:56equipment.

1:58The traffic has to be handed off between these layers.

2:02And of course, that's going to increase latency and complexity.

2:07The more pieces of equipment we have, the more links between equipment, all of

2:11these

2:12things add up to make this far more complicated as far as connecting the

2:17equipment together.

2:19Now when we compare this to the routed optical network, of course, we know that

2:25the routed

2:26optical network is a simplified architecture.

2:30The IP routing and the optical transport are combined into, we say here a

2:37single layer,

2:39meaning layer of management.

2:41It's still handling layer one, layer two, layer three of the OSI model.

2:47But from a management perspective, it's a single layer, meaning it's a single

2:52device.

2:53Of course, the way we do this is the routers have integrated optical transpond

3:01ers.

3:02This allows us to have that direct IP over DWDM connectivity, where we're

3:07sending our

3:08IP traffic directly over the optical circuit.

3:12At the end of the day, of course, that means that we have fewer devices.

3:16We know that fewer devices means that we don't have intermediate equipment, we

3:21don't

3:21have to purchase it, we don't have to maintain that extra equipment.

3:25It simplifies our overall management.

3:28And of course, all of this means lower cost compared to traditional networks.

3:34Just to expand on that, let's talk about operational complexity in a little

3:40more detail.

3:41So again, with our traditional service provider network, we had manual

3:46operations.

3:48This means that we had human intervention, which also can very quickly equal

3:54human error,

3:55but we had to have this human intervention to handle things like our provision

4:00ing, troubleshooting,

4:02ongoing maintenance.

4:04So all of these things had to be handled manually by humans.

4:09Or again, to be fair, we have had all sorts of software to aid in this, in the

4:15past, but

4:16nothing quite as complex as software to find networking.

4:20And of course, another big piece of all of these layers and all of these

4:24devices being

4:25separate is we often had separate teams to manage between the IP and the

4:31optical layers.

4:33This could have been whole different teams of people with different types of

4:37training,

4:38different specializations.

4:40And this of course means more personnel that we have to maintain and keep on

4:44staff.

4:45By bringing all of it together, we're going to get a big advantage here.

4:49Also traditional networks had static configuration.

4:54Things like traffic engineering had to have static rules, which leads to very

5:00limited

5:01flexibility.

5:02By implementing software to find networking, real time network monitoring, and

5:07reacting

5:08to that network monitoring in a dynamic fashion, we're going to solve a lot of

5:13the more complex

5:14problems that we have with traditional networks.

5:18Now as I said, there have been tools to help with all of this over the years.

5:25So it's not that it's been completely manual operation by humans.

5:30Of course, we know there have been other automation tools and things like that.

5:34But nothing quite as comprehensive as a full blown software to find networking

5:40solution.

5:41And that's of course what we get with our routed optical network.

5:45This is going to be fully automated and software driven.

5:49We're going to use like we said SDN for not only that provisioning, ongoing

5:54maintenance,

5:55monitoring, and so on, that's all going to help with traffic engineering as

6:00well.

6:00So all of this being automated takes the human factor out of it for mistakes.

6:06It also means that we can react in darn near real time to things changing on

6:12the network.

6:13And not only does it aid with dynamic traffic engineering and provisioning, but

6:20overall,

6:21automation just simplifies operations.

6:24Which if the operations are simplified means we can also do faster deployment.

6:29We can deploy things faster when it's fully automated.

6:32Also as far as updates, maintenance, things that need to change on the network.

6:37So policy changes, things like that.

6:40These can all be done very easily through SDN in our routed optical networks.

6:46And really all of this boils down to unified management.

6:51Rather than all of these layers being managed separately, different teams,

6:55different departments,

6:56we're going to have a single pane of glass.

7:00So a single management tool that's going to handle both the IP and the optical

7:07layers

7:07of our network.

7:09So we don't have to go a whole bunch of other places in order to configure

7:13things.

7:14Everything's going to be configured in one common location.

7:18Next, let's talk about performance.

7:22Traditional network versus routed optical networks.

7:25Well, with the traditional service provider network, we are going to have

7:30higher latency.

7:31Now again, we've had very high speed networks.

7:35We're doing a comparison between the two.

7:37So when we say higher latency, we're not necessarily saying high latency.

7:42There's a very subtle difference there.

7:45But higher than routed optical networks, that doesn't necessarily mean high in

7:50general,

7:51just so we're clear.

7:53But the reason we have the higher latency here is when you have those multiple

7:57layers

7:58and multiple devices, all of this adds processing delay.

8:03Each device adds its own encapsulation delays or serialization delays.

8:08So there's a lot of things here that are going to add to the latency.

8:12Everything else could be an issue is bandwidth overheads.

8:16When you start adding other layers like Sonnet and SDH, we're adding more

8:21headers to the payload,

8:23therefore overall decreasing the efficiency of the packet and therefore the

8:29usage of the

8:29bandwidth.

8:31And of course, another big one is going to be limited scalability.

8:34When you need to add capacity, think about this.

8:38You not only have to replace the optical device, but you would also have to

8:42change out the

8:42router that's connecting to it.

8:44So there's a lot more things that need to be upgraded.

8:48We're going to have to upgrade these multiple layers completely independently

8:52because it's

8:52all different hardware.

8:54Now, of course, we can still scale it.

8:56We've been scaling up our bandwidth and our network speeds since the beginning

9:00of networking.

9:01So yes, it can be done.

9:03Once again, we're comparing it.

9:05With routed optical networks, we're just replacing the one piece of equipment.

9:10So on our comparison sheet, that's what we're going to see here for our routed

9:14optical

9:14network.

9:15Not only are we going to have lower latency, why?

9:20Because we're doing IP right over the optical connection, there's no more

9:24intermediate processing.

9:27So this is going to reduce the number of devices and therefore reduce the

9:32latency.

9:32And also, of course, makes it highly efficient.

9:36If we're going to put IP directly over the DWDM technology, this is going to

9:41maximize

9:42the utilization.

9:43We're not going to have as many headers.

9:46Therefore, the overall packet efficiency is going to be much better when our

9:50packet efficiency

9:51is better, the usage of the bandwidth gets better.

9:54And finally, we're going to have that better scalability because while we're

9:58only updating

9:59the one system, everything is integrated.

10:02And therefore, we can just upgrade that one system.

10:06And if we do have to upgrade it, the upgrade process is going to be fully

10:10automated for

10:11the deployment of the new upgraded equipment.

10:14It just makes it so much easier when SDN is involved.

10:19Another big thing to consider, of course, is also cost.

10:23Money is always an issue.

10:24So let's talk about these two things together.

10:27So traditional service provider networks, we're going to have a higher capital

10:33expenditure.

10:34Why?

10:35Well, we've sort of clarified by now that we're buying separate equipment.

10:41If we're buying separate equipment for each layer, that's of course going to be

10:44more layout.

10:46And again, remember, it's not just the hardware.

10:50It's also support contracts.

10:52It's power.

10:54It's cooling.

10:55It's real estate, where are we putting this equipment?

10:58It's more personnel to manage the equipment.

11:01And that's also what leads here to the higher operational expenses as well.

11:05So not only do we have to purchase them, so again, things like your support

11:10contract

11:10and the purchasing of the equipment itself, that's usually going to be under

11:13your capital

11:14expenses.

11:15And then your operational expenses, as we're managing these multiple layers,

11:20that's where

11:20those other things are going to come into play.

11:23It's energy costs.

11:26And again, not just energy for the equipment itself, but also energy for the

11:29cooling and

11:30so on, lighting in the building that it's in.

11:32Now, those sort of things are, of course, sort of minuscule because the

11:36equipment that

11:37you do have to buy also has to be in a building with lighting.

11:40But again, you get the point that every little piece of equipment adds to the

11:44total equation,

11:46so the less we can have the better.

11:48Again, comparing this to our routed optical network, it's going to have lower

11:52capital

11:53expenditure because we're buying fewer devices.

11:57These integrated routers are going to replace the standalone opticals.

12:01Now, again, might those interfaces cost a little more than a traditional ether

12:07net interface?

12:09Of course they can.

12:10But it's not going to cost as much as buying completely separate equipment like

12:15we had

12:15to up here.

12:17So a slightly more expensive interface sort of isn't anywhere near the same

12:21problem as

12:22buying completely separate equipment.

12:24This is, of course, also going to lower the operational expenses for several

12:29reasons.

12:29One is the simplified operations.

12:31Again, when you have SDN managing your entire network, this is going to cut

12:36down on the

12:36costs of management, the needed personnel and so on.

12:41And it's also, of course, reduced energy because we're powering less equipment,

12:45we're

12:46cooling less equipment, and so on.

12:48So from a cost perspective, routed optical networking is sort of really the way

12:53to go.

12:54Now once again, you could make the argument from a cost perspective that you

12:58might have

12:59to upgrade hardware or change hardware in order to do the routed optical

13:05networking.

13:06But if we time or plan that along the lines of equipment replacement, then that

13:11's not

13:11so much of a big deal.

13:13Also, we may find out that these lower expenses down here actually end up out

13:19weighing the

13:20cost that we have to outlay for our capital expenses.

13:23So again, the lower operational expenses may offset the capital expenses that

13:29we need

13:30to buy the equipment.

13:31Again, these are all things that have to be looked at in each particular

13:34environment.

13:35It's going to depend on how old your existing equipment is.

13:38There's so many factors.

13:39We can't really have a full discussion on it here, but you just need to plan it

13:43out.

13:43How much are we going to save?

13:45How much do we have to spend?

13:47What point do we break even on the equipment and then start actually saving

13:50money and so

13:51on?

13:52These are all decisions that have to be made, whether you want to skip over to

13:55routed optical

13:56networking before an equipment refresh time, or do it at the equipment refresh

14:02interval

14:03and just buy the new equipment then.

14:05These are of course all decisions are going to be based entirely on how your

14:08service provider

14:09operates.

14:11Another big one is going to be flexibility and agility, always important

14:16aspects with

14:17a traditional service provider network.

14:20It's going to be fairly rigid.

14:22It's pretty hard to quickly adapt to changing traffic patterns.

14:26Now, don't don't misunderstand here.

14:29We're just saying it's hard again compared to routed optical networks.

14:36It can of course be done.

14:38If you've been doing traffic engineering and even dynamic traffic engineering

14:41for a while,

14:42it's just not as easy.

14:44So comparatively, it's harder.

14:48Same with provisioning.

14:50This has traditionally been a manual process.

14:53Again have we had automation tools and such.

14:57Yes.

14:58However, still not quite as good as our routed optical network.

15:01Again, the big advantage of the routed optical network is its dynamic and agile

15:07.

15:07We have those automated tools.

15:09That's really the big thing here and of course, we're talking about SDN.

15:13This allows for real time traffic adjustments, faster provisioning because it's

15:19all automated.

15:20Also less prone to errors and mistakes as well.

15:23And of course, all of this being automated makes it far easier to respond to

15:28surges in

15:29demand, things changing on paths, traffic paths getting busy, getting congested

15:35, maybe

15:35even starting to spit out too many errors and retransmissions on a particular

15:40path.

15:40We can dynamically change things to route around issues such as congestion and

15:46errors

15:46on circuits.

15:48Now we have sort of drilled this home already, but another big factor of course

15:52is the energy

15:53efficiency.

15:54Now, we've already said of course, the less equipment, the less energy.

15:58So just to wrap this up with a little bit more detail in our traditional

16:02service provider

16:03network, it's going to take more energy.

16:05Again, we're comparing this to the routed optical network because again, we

16:09have a larger

16:10number of devices.

16:12It's just that simple.

16:13So we're going to need additional cooling, which I've already mentioned for

16:17these equipment

16:18heavy infrastructures.

16:19And again, that might require more battery backup.

16:23Not to mention the extra service contracts we've discussed.

16:26Lots of different factors come in to having more equipment.

16:30And of course, with the routed optical network, since we have those fewer

16:34devices, it's a

16:35more streamlined architecture.

16:37This is going to reduce power.

16:40That's of course a huge factor.

16:42And again, this is going to be far better suitable for sustainability goals

16:46moving forward

16:47because everything's going to be much more environmentally friendly, more green

16:52, and of

16:53course, less expensive.

16:55So just to wrap this all up and put it all together, I put a table together

16:59here for us.

17:00About all these different things that we just discussed.

17:03So just as a quick recap.

17:06So from an architecture perspective, remember the traditional is layered with

17:10separate IP

17:10and optical, where of course, the big trick here with routed optical network is

17:15that everything

17:15is integrated.

17:16It's one unit for the devices.

17:19That means we have routers, transponders and amplifiers.

17:22And here we just have routers with the integrated transponders.

17:27From operations, it's manual and layer specific.

17:31Here it's automated and united.

17:34From a performance standpoint, higher latency, lower efficiency, and of course,

17:39lower latency

17:39higher efficiency.

17:41It's just more efficient when it comes to performance.

17:44For scalability, we're looking at limited and costly versus easier and cost

17:50effective.

17:51That's what it comes down to cost as well, where we have higher capital and

17:55operational

17:55expenses versus our lower capital expenses and operational expenses.

18:02And then of course, for the energy efficiency, we know this is energy intensive

18:07.

18:07Again, comparing it to routed optical networks, they're going to be more energy

18:14efficient.

18:14So in this video, we spent some time going through comparing routed optical

18:19networks

18:20to traditional service provider networks.

18:24Hopefully providing a better understanding for you of the fundamental

18:27differences between

18:29the two as we're hopefully moving from traditional networks more into the

18:34routed optical environments.

18:36[BLANK_AUDIO]

0:00So, now that we have a really good grasp on rounded optical networking and how

0:07it compares

0:07to traditional networking, let's take a few minutes to look at Cisco's current

0:13product

0:13offering in this space.

0:16Now, keep in mind, anytime we look at hardware, it's going to be time sensitive

0:21, meaning it's

0:22going to be the products that are available at the time of this recording.

0:27Please keep an eye on their pages, find out new equipment that's coming out,

0:31updates to

0:31current equipment, in other words, sometimes they'll keep the same product but

0:36just increase

0:36its specifications.

0:38So what we're going to do is we're going to jump into their main rounded

0:41optical networking

0:42page and we're going to take a look at the different products that they offer

0:47from interfaces

0:48to the actual routers and switches to the different software that's available

0:53to make

0:53all of this work.

0:54So that said, let's start by jumping in and taking a look at some of the

0:58interfaces that

0:59are available for rounded optical networking.

1:04So the first thing we're going to talk about are the pluggable optics.

1:08So for this, we have four different QSFPs.

1:12So this starts with the QSFP DD 400 gig ZR plus high transmit power QSFP.

1:22We also have the non high transmit power.

1:26So the standard ZR or ZR plus, we have the 400 G ERI and there's the pluggable

1:35open line

1:36system.

1:37Let's hop over to Cisco's web page about these products and take a look at them

1:42in a

1:42little more detail.

1:44So as we can see, this is Cisco's web page, particularly for Cisco rounded

1:50optical networking.

1:51This link is provided below this video so you can follow along if you like.

1:56But if we scroll down a bit, this is going to give us some pretty cool

1:59information here

2:01about rounded optical networking.

2:03Most of this stuff we've already covered.

2:05For example, the fact that it's going to converge IP and optical.

2:09We talked about how it reduces your capital expenses, lower environmental

2:14expenses.

2:14We talked about streamlining network operations and how this is going to set us

2:19up for future

2:20growth.

2:21So we're going to talk about a lot of this stuff.

2:24If we scroll down a little bit more, it'll give us a description here about

2:27what is rounded

2:28optical networking and so on.

2:31We can see also there's a couple of videos here you can watch if you like to

2:34get a little

2:34more information from Cisco's perspective about this technology.

2:39But what we're really here to look for is this section right here where we're

2:43going to talk

2:44about the different products.

2:45So the first one here we can see is the pluggable optics.

2:49We have the four SFPs here that we listed and notice for each one of these we

2:54can go to

2:54the data sheet.

2:56So we'll go up here to the first data sheet.

2:59Notice first that the high power versions Cisco also refers to as bright.

3:06So we can scroll down here a little bit.

3:07We got a view of what this product actually looks like under the product

3:11overview.

3:12It's of course going to give us some more detailed information about this

3:16particular

3:17QSFP.

3:18And of course if you really want to on any of these we can scroll all the way

3:23down to

3:24things like products sustainability.

3:27We have product specifications where you can find out very, very detailed

3:32information about

3:33each of these products.

3:34If we go back the ZR and the ZR plus is going to be almost identical here as we

3:40come in.

3:41Obviously the graphics and the information are a little bit different here in

3:44the product

3:45overviews but again we can get information about each of these products that

3:50are available.

3:52So we can see that each of the four SFPs have a data sheet here available.

3:56We don't have to go through each one but this is going to provide more

3:58information about

4:00each of these products.

4:02Next up we have the various routing platforms that are available.

4:06So we have the Cisco 8000 series routers.

4:09We have the NCS 5500 series.

4:13We have the NCS 5700 series.

4:16Also the 500 series and the ASR 9000s as well as the Nexus 9000 series switches

4:25.

4:25And once again if we go back over to the product page and now we click on

4:29routing platforms

4:31we'll see that again we have features and models and so on.

4:35Again each of these pages is going to be a little bit different but just as an

4:39example

4:39we could go here to the 8000 series routers.

4:43Of course we get a picture of one of the available models and as we scroll down

4:48we can find out

4:49more about the features.

4:50Here we can see the different models that are available.

4:53So there's the 8100, the 8200, the 8700.

4:57Each of these of course has its own data sheet but we can see the available

5:01bandwidth and

5:02how large these different devices are.

5:05So these are the fixed systems but notice over here there's also modular

5:09systems.

5:10So these are of course considerably larger.

5:13We have 10, 16, 21 and 33U under the 8800 series and then over here on the

5:20right we also

5:21have information about the available line cards for the 8800 series routers.

5:27There's also centralized systems here as well, the 8600 series and as you can

5:32see some of

5:33these even have a 3D model available.

5:36So we can actually spin this around, get a good idea of exactly what this

5:39device looks

5:40like so we can actually see all of it and of course you can click on any of

5:45these pluses

5:46it'll pull that particular part out and talk more about it.

5:55So we can get a lot of really good information about all the different routers

5:58that are available

5:59in the product line.

6:02Next up we have network automation.

6:05Network automation is handled by Cisco's Crosswork Network Automation product.

6:11Now if we go back over to the product page here click on network automation.

6:16Again we see here that it's the Cisco Crosswork Network Automation.

6:20We go to explore features.

6:22This when we get sort of a small screenshot of it over here to the right there

6:26's of course

6:26a video here you could watch to get more information.

6:30Honestly down here under the overview it lists a lot of the features however we

6:35don't get

6:35like screenshots or things like that of it so much down here but we do get a

6:39lot of things

6:40about the software such as the hierarchical controller, the network services

6:46orchestrator,

6:47the cross work planning, the evolved programmable network manager, the network

6:51controller, the

6:52optimization engine, the WAN automation engine, workflow manager and so on.

6:57So as we can see there's a lot of different components that are all included in

7:02this software

7:03defined networking solution.

7:06Next we have service assurance.

7:09For this the product is Cisco provider connectivity assurance.

7:13Once again if we go back to our product page under service assurance we see the

7:18product

7:19listed here if we go to explore features.

7:22We can see that the main overall goal here is to gain end to end visibility.

7:27They say like never before.

7:29So again to the right we sort of see a glimpse of what the product looks like

7:33if we scroll

7:34down it's of course going to tell us more information about the product.

7:39There's a video here we can watch for a little bit more information about the

7:43product if you

7:43desire here a little bit further down they're talking about the analytics and

7:49the sensors.

7:50And if you really want to take a look at this a little bit more down here at

7:52the very bottom

7:54there's an option here to get a demo on this particular product.

7:59Next up we have some products dedicated to optical networking.

8:03This specifically is the NCS 1000 series and the 10 10 series.

8:09So let's jump over and take a look at those.

8:12So we see here the data sheet for each of these items.

8:15Let's go ahead and take a look at the 10 10 at the actual data sheet.

8:19Now we can see this one's fairly long but if we scroll down just a little bit

8:24we get

8:24some information from the product overview the solution overview and we can see

8:31here a

8:31bit about the hardware and what this product actually looks like.

8:36So again these are products dedicated just to optical networking and then

8:41finally we

8:41have service convergence.

8:44This is going to involve private line emulation or PLE and the PLE modular port

8:51adapter.

8:52So let's switch back over.

8:54Here we see the information on private line emulation.

8:57Again we can look at the solution brief.

9:00This will give us a lot more information about what PLE actually is and what it

9:04's for and

9:05how it can actually emulate a private line between our customers.

9:10So we have the data sheet on the PLE modular port adapter.

9:15So if you click on read data sheet here you'll see all the different

9:19information about this

9:20particular product.

9:22So again these are just some of the products that Cisco offers in their routed

9:26optical

9:26network family.

9:29So in this video we took a look at some of Cisco's offerings in the routed

9:33optical network

9:34space.

9:36Now again remember that this is just current as of this recording.

9:40This of course is going to change all the time so always keep an eye on the

9:44Cisco product

9:44pages to get the latest information.

9:47[BLANK_AUDIO]

0:00[MUSIC PLAYING]

0:09Next up, we're going to take a look

0:10at operation, administration, and maintenance or OAM.

0:17Specifically, we're going to be looking at this for ethernet.

0:20Now, there are many different versions of OAM.

0:24We'll talk a little bit about those.

0:26But we're mostly going to be focusing on OAM for ethernet.

0:30So let's jump in and see what this is all about.

0:33So there's different parts of our network

0:35that need to be monitored by OAM.

0:38But the good news is it does have a method

0:41to cover three different parts of the network.

0:43The first is based on IEEE 802.3ah.

0:49And this is to monitor a single link.

0:52And it monitors link integrity.

0:54The second method is 802.1ag.

0:59This is also known as connectivity fault management

1:02or CFM.

1:03This is to monitor end-to-end connectivity

1:06for an ethernet service, so something like ethernet

1:10over MPLS, something along those lines,

1:13so when you don't just get a link light for ethernet

1:16to be up or down, it's going over something else,

1:19and we need a better way to monitor it.

1:21Next is MPLS OAM, sort of self-explanatory.

1:25But this is to run over the MPLS portion of the network.

1:29Now, as I mentioned during the introduction, here

1:32we will be focusing specifically on ethernet OAM or EOAM.

1:39So let's take a look at some of the more detailed attributes

1:42of that.

1:43So, first, it does do discovery of EOAM capabilities.

1:49So in other words, it will discover its neighbors

1:51and learn specifically what their capabilities are.

1:55It also has critical event detection,

1:57things like links going down.

1:59It will alert us to those sorts of things.

2:01It has a feature called wire-speed data loopback, which

2:04we'll look at in a couple of minutes,

2:06remote variable retriever, link event reporting.

2:09And this can be implemented on any point-to-point ethernet

2:13link.

2:15Now, as far as the mechanism that this

2:16uses to actually communicate, this

2:19uses a destination MAC address.

2:21Again, it's a well known address of 0180.c200.0002.

2:30And it uses this for its PDUs or its protocol data units.

2:36These are sent at a maximum of 10 per second.

2:40And the idea behind this is that it has a very low impact

2:44on normal operations.

2:46In other words, this is not going

2:48to get in the way of user traffic

2:50just to maintain and monitor the link.

2:53It does use four different message types.

2:56We have the informational message type, which

2:59is used for the discovery.

3:01We have event notification, which

3:04is used for the actual link monitoring, which

3:06is, of course, the main function here.

3:08It has loopback control message, which

3:11can be used to either enable or disable remote loopback, sort

3:16of as the name implies.

3:17And there's also a vendor-specific section,

3:21which can be used by various vendors

3:23to implement their own sort of messaging

3:25into this for whatever feature that they want to implement.

3:28Now, we did mention that during the discovery process,

3:31the neighbors do discover things about each other.

3:34And those things are, first off, the OAM mode.

3:38A device can be operating in either active or passive mode.

3:42It'll also learn the OAM configuration,

3:44which, of course, advertises specifically the capabilities

3:48of the local OAM device.

3:51This way, of course, the remote side

3:53learns what your capabilities are.

3:55So much like a lot of routing protocols do,

3:58we're doing a capabilities exchange.

4:01Particularly for things like these vendor-specific message

4:04types up here, we would have to know

4:06whether you support certain message types

4:08and stuff like that.

4:09So this is why the capabilities exchange is so important.

4:13Also, the OAM PDU configuration-- so this

4:16is essentially the timers.

4:18This is your frequency and rate limiting.

4:21As we talked about up here, there are timers.

4:25We said it was a maximum of 10 per second.

4:28That doesn't mean we might not be going less than that.

4:31So part of this is to exchange those timers of how frequently

4:34we're going to send these PDUs.

4:36And there's also a platform ID, which is, again,

4:39like a lot of routing protocols use,

4:41very similar to a router identification.

4:44This is a combination of an OUI as well as a 32-bit vendor ID.

4:52Now, of course, when things go wrong,

4:54we have to have some way to report the errors.

4:57So we do have many different error types here.

5:00So let's go through these.

5:02The first is the error symbol period.

5:05And this is the number of symbol errors

5:08that occur during a specified period of time

5:12to exceed a threshold.

5:14Next up is the error frame.

5:17This is the number of frame errors

5:21that were detected, again, during a specified period

5:25to exceed a threshold.

5:26Then we have the error frame period,

5:30which is almost the same as the error frame

5:33except this is per n frames.

5:36Remember, of course, that n is just a number, so,

5:39say, per 100 frames.

5:41So this would be the number of-- again, this is frame errors.

5:44But it's within the last n frames, so how many

5:48errors out of the last 100.

5:51So rather than using a specified period,

5:53it's just out of however many frames.

5:56Next, we have the error frame seconds summary.

6:00This is the same as error frame period.

6:03But this is the errors per second in n number of seconds.

6:09So we're using the n again for a number.

6:12So, again, this is error seconds.

6:15But it's within the last n number of seconds.

6:19We also have methods to detect a remote failure,

6:22so if something happens on the other end of the link.

6:25And this can also report several different fault conditions.

6:29The first is a link fault which is, of course, really nothing

6:33more than a loss of signal on the receiver side.

6:38Now, the interesting thing here is

6:41this can only operate if the physical side can

6:46do an independent transmit and receive.

6:50The reason for this, of course, is how would you

6:54signal your loss to me--

6:56remember, of course, this is remote failure--

6:59if the link is down in both directions.

7:02So this would have to be you're still possibly transmitting.

7:05But you can't receive.

7:06Next is my personal favorite just

7:09because I think the name is rather humorous, the dying

7:12gasp.

7:12I don't know.

7:13It sounds so dramatic to me.

7:15But this is an unrecoverable condition.

7:19That sort of sounds like a dying gasp to me.

7:22But this could be something like a power failure

7:24or something like that.

7:26The remote device is not coming back.

7:28It's that simple.

7:29And then, of course, we just have a critical event, which I

7:33just--

7:34again, this is a little bit humorous to me

7:36because it's just an unspecified critical event.

7:41So critical event is sort of everything else.

7:46Now, the last thing we want to talk about

7:48is that loopback mode that we spoke about at the beginning

7:52of this section.

7:53So an OAM device can actually place its peer

7:57into loopback mode.

7:59So, basically, what you're doing is

8:01you're asking your peer to loopback everything

8:05you send back to you.

8:07Now, of course, the main purpose for this

8:09is using it for fault localization and, specifically,

8:14link performance testing.

8:16So in other words, we want to test a particular link.

8:19So we put the other end of it into loopback mode.

8:23We do this with the command "ethernet OAM loopback enable."

8:28Of course, "disable" would turn that back off.

8:31And this will put the remote end into loopback mode.

8:35In this mode, all traffic, except the PDUs themselves,

8:40will be sent right back to the device sending them.

8:44So I can send you traffic.

8:46You send it right back to me.

8:48Again, very useful for fault localization and link

8:51performance testing.

8:53In this video, we took a look at OAM,

8:57specifically really focusing on ethernet OAM.

9:01But we saw how we can use it to monitor the link

9:04and how it can send error messages if either there's

9:08problems on the link or problems with the remote end.

9:11And, finally, we looked at how we can actually

9:13configure loopback mode if we want

9:16to do local testing on a circuit for either performance

9:19or faults.

9:21I hope this has been informative for you.

9:23And I'd like to thank you for viewing.

0:10Our final topic for this skill is

0:12going to be ERP, or Ethernet Ring Protection.

0:16And this is one of those technologies,

0:18where the name says it all.

0:21This is an ethernet environment.

0:23It involves creating a ring, specifically a redundant ring,

0:28that protects the first ring.

0:30So it's using rings for protection.

0:33This is very, very similar to say, for example,

0:37how a SONET ring works.

0:39And much like that, the idea here

0:41is to have incredibly quick failover

0:44to that redundant ring.

0:46So let's jump in and take a look at the details

0:49of how this actually works.

0:52So as we just stated, the idea behind ERP

0:56is that this provides a ring topology to protect ethernet.

1:02Now, a little more detail about this,

1:04it uses a specified link called the Ring Protection

1:09Link, or the RPL.

1:11So for example, if we were to look at our diagram over here

1:15to the right, the RPL, we could say, for example,

1:19would be the outer ring here or the orange ring.

1:22And what's going to happen is one of our devices

1:25is going to block that network on one of those rings.

1:31And that way, as soon as there is a failure on the ring

1:35we're actually using for traffic.

1:37So say we have a failure here.

1:39It will immediately unblock the RPL link.

1:43Now, in order to know how all of this is going to work,

1:46this does connect to a special port called the ring port.

1:51And then it uses Connectivity Fault Management

1:54from OAM, which remember, we discussed in a previous video

1:58to detect that fall.

2:00So again, this is relying on CFM from OAM.

2:04Now the cool thing is this does provide

2:07a 50 millisecond recovery time just like a SONET ring would.

2:12So very, very high speed failover.

2:16And I bring this up mostly in case

2:18anybody who's more familiar with ethernet is looking at this

2:22and saying, couldn't we do the same thing

2:25with say spanning tree?

2:27And the problem with that is, it's just literally not

2:30this fast.

2:31This is a much, much faster system for repairing ethernet.

2:35Now, it does, like we said, work a little bit

2:39like spanning tree by blocking one of those ports.

2:43So again, if everything is up and running,

2:45if we don't have a failure, then we'll

2:48be blocking on one of our ports.

2:50Now, there are different RPL node types.

2:54The first is the RPL owner.

2:56The RPL owner is the device that does

3:00the blocking on that RPL link.

3:02So in our example, this would be the RPL owner.

3:06Optionally, we have something called the RPL neighbor node.

3:11Now, the RPL neighbor node could in our example either

3:14be this router up here, or it could be this router over here.

3:19It's a router that is a neighbor to the RPL owner.

3:24And the idea is that it then blocks its side of that link.

3:29So it would, for example, block over there as well.

3:32It's just a little bit more complete.

3:34But this is technically optional.

3:37Also optional is the RPL next neighbor node.

3:42Now this one, we can see is a little bit more interesting

3:44because it can be adjacent to either the owner

3:48itself, which would follow the yellow arrows we already

3:51put there, or it could be adjacent to the neighbor, which

3:55means it could also be this router up here.

3:58So this can be either directly or indirectly connected

4:02to the owner because it can also be connected to a neighbor.

4:06But the point is, this is used for optimization

4:10of the filtering database or the FDB.

4:14This is also an optional node.

4:17Remember that this one is optional as well.

4:19The only node type that we have to have for ERP

4:23is the RPL owner.

4:26In this video, we took a look at how we can use ethernet ring

4:30protection to provide very, very fast 50-millisecond failover

4:36to ethernet much in the same way that a SONET ring offers

4:41protection to SONET.

4:43I hope this has been informative for you.

4:45And I'd like to thank you for viewing.

0:00[MUSIC PLAYING]

0:08Congratulations on completing another skill.

0:11Now, it's time for a review in the form of a quiz.

0:15Let's jump in with our first question.

0:19MPLS operates at which layer of the OSI model?

0:30So if you remember from our discussion, what you'll have is

0:34you'll have the original layer 2 header,

0:36then we have the MPLS label, and then

0:40we'll have the original, usually layer 3.

0:44Technically, this could also be another layer 2 header

0:46because we can the layer 2 over MPLS.

0:49But either way, this is getting inserted

0:51between layer 2 and layer 3.

0:54So that means that our correct answer here

0:56would be number three, between layer 2 and layer 3.

1:00So number 3 is our correct answer.

1:04Next question, SR or segment routing

1:08is best defined as which of the following?

1:17Let's go ahead and work our way down our list.

1:20First, we have destination routing.

1:22Well, this is what we normally do,

1:24so this is not what segment routing is going to be.

1:28Host routing, not really a term we really use.

1:31You could maybe make the argument

1:33that that would be routing based on a host route perhaps,

1:36but that would still be destination routing,

1:39and therefore, that is also not our correct answer.

1:42Fast routing, again, not a term we normally use.

1:46You could maybe say that this is like fast reroute

1:49or using fast switching, but either way, this

1:52is not segment routing.

1:54Number four is source routing and this is correct.

1:58Segment routing is a form of source routing,

2:03so number four would be correct.

2:05And just for completeness, our last answer here

2:08end to end routing, this is also not correct.

2:12So our correct answer for this question

2:15is simply going to be number four that segment routing is

2:20a form of source routing.

2:22Final question, what is the most common protocol

2:26stack used by providers today?

2:33This one is really mostly a recall question.

2:37Some of these aren't really even possible,

2:39but the one we're looking for here

2:41is that we would run IP over MPLS and the MPLS running

2:48over Ethernet.

2:49So number two would be the correct answer as far

2:53as the most common stack that we're going to be using today.

2:58So that concludes this quiz.

3:00If you find that you are missing any of the information needed

3:03to answer these questions, I would

3:05encourage you to go back and review the referenced source

3:09on each question.

3:10Otherwise, congratulations on completing

3:13Describe Network Architecture.

3:15I hope this has been informative for you

3:17and I'd like to thank you for viewing.