网络课程笔记

00:00 Hello and welcome to this lecture.

00:02 Direct Connect Sitelink.

00:03 Now this is a new feature of Direct Connect, which was launched during the Reinvent 2021, and this

00:10 is now slowly being adopted by the lot of customers of AWS.

00:14 And now in this lecture, let's understand what is sitelink and what problems it solves.

00:20 So first of all, what is Sitelink?

00:22 So Sitelink connects on premise networks through AWS, Global Network Backbone.

00:27 Now, essentially what it means that if you have, say, for example, your own customer data centers

00:33 and there is no AWS.

00:35 As of now in the picture, and if you need to have the high capacity bandwidth or a connectivity between

00:41 these two data centers of your own, typically you will go with some network service provider and set

00:47 up that link.

00:48 While this works, there are many problems with this kind of setup.

00:53 For example, if it's a small company, then they might just go over the Internet for this connectivity

00:58 and you know that Internet cannot provide you the consistent bandwidth.

01:02 Right?

01:03 Or maybe if you need a higher bandwidth, then you might get into the long term contracts with the network

01:09 service provider.

01:10 And then you are locked in for many years and many a times these are like point to point connections

01:15 and you don't get much of the flexibility when you are to expand your network to other geographies.

01:20 So looking at all this problem, this is very inflexible kind of connections.

01:25 Now with AWS and AWS direct connect this, things change.

01:30 So as you know, there are AWS regions and there are direct connect location across 100 plus location,

01:37 right?

01:37 Now, with Sitelink, what you can do is you can rather connect your data centers to nearest direct

01:44 connect location, and then you can use this direct connect locations to route your traffic from one

01:51 side to another.

01:52 So as of today, there are 115 location, so you can choose the nearest of yours.

01:57 For example, if you are in the US, then you might want to select a Boston one.

02:01 If you are in Mumbai, you want to select a direct connect location in Mumbai.

02:07 And as you know, all these direct connect locations are already connected over AWS Backbone Network.

02:13 What you just need to do is enable that routing of the network and Sitelink exactly does that thing.

02:21 Once you enable the AWS Sitelink on your direct connect connections, then it completely bypasses AWS

02:28 region and directly from your direct connect locations.

02:31 Traffic is routed over the shortest path.

02:34 Now this is a very good option now for customers to really use AWS Backbone Network for connecting their

02:43 sites.

02:43 Even they are not using any AWS services.

02:46 So that's what a direct connect sitelink is.

02:49 I hope that's clear and we'll see some of the examples as well.

02:53 How it changes those architectures which we saw earlier.

02:58 Okay, so without sitelink you might have seen this architecture.

03:01 Maybe colors are a little different, but then you have multiple data centers and there is a direct

03:05 connect gateway you connect to, and then you can connect, direct, connect, gateway to different

03:10 vpcs across regions, right?

03:12 And if you remember, there was one problem that direct Connect Gateway cannot allow the routing of

03:18 the traffic from one side to another because it doesn't support the transitive routing.

03:22 So that was a problem.

03:24 And if you remember, the solution was you need to use now two direct connect gateways and also you

03:29 need to use transit gateways along with that.

03:32 So we saw this architecture where you could have two direct connect gateways attached to the transit

03:36 gateways, and then you can have the transit gateway peering, and now this traffic can go from one

03:42 side to another via this route.

03:44 Now, while this works, and so far it worked.

03:47 But there are some additional cost for this setup, right?

03:51 Cost in terms of money and cost in terms of the network hops and latency.

03:56 Right.

03:57 Because Transit Gateway has per gigabyte data processing charge.

04:01 So that would be an extra cost as well as there is a network hop there because you also introduce now

04:08 Transit Gateway.

04:09 So this might have worked so far, but has launched the SITELINK, which fixes this problem.

04:16 Now with Sitelink, you don't really need to get any devices in AWS region like a transit gateway.

04:22 You can directly route traffic from your direct connect locations using the direct Connect Gateway.

04:28 What you have to do is provision just a private Vif or a transit Vif on existing connection or create

04:34 a new connection and connect it to the same direct connect gateway and you just enable the sitelink

04:40 on those waves.

04:41 One Sitelink is enabled.

04:43 Now data can go over from one side to another, so this path is now allowed.

04:50 So that is what Sitelink does.

04:52 Okay with that?

04:53 Now let's understand some features of Sitelink.

04:56 First of all, Sitelink is enabled at the VIF level and it is supported for private and transit Vif

05:02 only.

05:02 It is not supported for public Vif for the obvious reason that it uses direct connect gateway for routing

05:08 the traffic.

05:09 And if you create a wave, you can see that there is this setting which enables the sitelink.

05:16 Now, don't enable this setting unless you really require that kind of routing because it has additional

05:22 cost per hour and we'll talk about that.

05:24 So keep it unchecked until you really want it.

05:27 Right?

05:29 Sitelink is also supported on any combination of dedicated or hosted connections with different port

05:36 speeds.

05:37 What it means that if one of the site is connected to Gateway over, say, one Gbps link and another

05:44 data center is connected to same gateway over different direct connect connection over say hosted connection

05:51 of 50 Mbps.

05:53 Both terminate at the same direct connect gateway and that doesn't matter.

05:58 The traffic still routes so you don't need to have the same connection or speeds at both the ends.

06:02 They can be different.

06:05 Now, in case of Sitelink, your traffic takes the shortest path.

06:09 Now, understand that we are now talking about the connectivity from any direct connect location to

06:15 any other in the world.

06:16 So one can be in the US, another one can be in Japan and still the traffic flows and then it goes over

06:23 the AWS Backbone network taking the shortest path.

06:27 You can turn on and off the sitelink in minutes.

06:30 Now, this is important.

06:31 You don't have to recreate anything if you have existing vifs You can also enable this setting on that

06:37 VIF and it takes into effect in few minutes or while creating the VIF.

06:41 You can also turn on those settings.

06:43 It supports both IPv4 and IPv6 routing prefixes and traffic, and it can support different kind of architectures

06:52 like a full mesh architecture where you have multiple sites and you want to connect to those, or you

06:58 want to make sure that your one site is connected to a particular site only and a third site cannot

07:05 access that data.

07:06 And what I mean by that, let's let's understand that by looking at the architecture, so full mesh

07:12 connectivity.

07:13 So imagine you have your data centers across the world, you are really a multinational company and

07:20 you want to connect all these data centers together with AWS Backbone Network.

07:24 What you will do is you will connect your data centers to nearest AWS, direct connect location based

07:30 on which country and which city your data center is.

07:33 Once you connect that, you just have to create waves with a transit Vif or a private Vif on all those

07:41 direct connect connections and connect it to the same direct connect gateway.

07:45 Once you do that, all the sites can communicate with each other.

07:48 So that's a full mesh connectivity.

07:50 The other type of connectivity you might want to have is maybe you have your own data centers and you

07:56 want to connect to your partner networks and you could have multiple partners and you don't want that.

08:01 All these partners communicate with each other, but you should be able to communicate with Partner

08:05 one and Partner two.

08:07 So something like this, you have your own data centers and there are two partner data centers.

08:11 Now, in this case, what you will do is rather you will use two different direct connect gateways,

08:16 one for partner, one connection and another for another partner.

08:19 And in this case, again, you will create a direct connect connection, create a whiff, connect it

08:25 to the same direct connect gateway for partner one That's a green link and you will have a VLAN tag

08:32 on that BGP connection.

08:34 Now, once that happen, this customer can talk to the partner one but cannot talk to partner two.

08:40 Now if you want to enable the communication, you just create another VIF on top of the same connection

08:45 of course with different VLAN tag and then another partner will have the direct connect connection and

08:52 it also creates the wave which connects to the another direct connect gateway.

08:57 Once you do that, you have now isolated network connectivity using the Sitelink and direct connect.

09:04 There is one more pattern where it looks similar, but maybe you have your own data centers.

09:10 There are no partners, but then within that you have network segregation.

09:13 For example, there is a production network and there is a test setup network and you don't want production,

09:19 network and test network to go over the same connection.

09:23 Then also you can achieve that, but just that in this case you need to take care of, you know, routing

09:28 at your end as well.

09:29 What I mean by that is in this case, you will create a similar connections, as we said.

09:35 So this Amber line is about, say, a test network, right?

09:39 You connect using the two different direct connect connections and terminating the Wips into the same

09:45 direct connect gateway.

09:47 And at your router you will have the virtual routing forwarding enabled.

09:52 So this router should understand that all the traffic going to this test workload goes through this

09:58 link only.

10:00 Now once that is done you can have similar setup for a prod network.

10:05 For example, you will have another set of connection whips connecting to different direct connect gateway

10:11 to redirect that traffic to the prod workload only so you can very well set this kind of isolated connectivity

10:18 as well.

10:19 So pretty much that's it about the Sitelink, just that you also need to know about the cost.

10:24 As I said, there is a cost per hour of the sitelink while it is enabled on the wave.

10:30 So if you tick that box here, then there will be $0.5 per hour, which is a lot of cost.

10:37 So even if you are not using the Sitelink feature or you are not transferring the data, but you have

10:44 ticked this, then also you will pay for this cost.

10:47 So be aware of that.

10:48 And then there is also a data transfer cost similar to the direct connect data transfer cost.

10:54 It depends on what the source is and what the destination is from where the traffic is coming with respect

11:00 to the direct connect locations.

11:01 So if distance is too much, then there will be additional cost.

11:05 But if it is within the same GEO, typically it is $0.02 per GB similar to the cost basically.

11:12 So these are the cost factor for SITELINK.

11:16 So that's it about the Sitelink.

11:18 Just one thing you need to remember if you want to connect multiple customer data centers using AWS

11:23 Backbone Network or a direct connect, then you can use AWS Sitelink.

11:29 So that's it for this lecture.

11:31 Thank you.