WEBVTT 1 00:00.000 --> 00:04.940 So if we can collapse our distribution and core blocks together, when is it 2 00:04.940 --> 00:08.000 required for us to have a true three-tier model? 3 00:08.000 --> 00:12.240 Where we have dedicated hardware at the core and at the distribution layers, it 4 00:12.240 --> 00:14.000 's separate pieces of hardware. 5 00:14.000 --> 00:18.550 So let's think about a mid-size organization. Let's say that we have a 6 00:18.550 --> 00:21.000 distribution block at a location. 7 00:21.000 --> 00:24.000 It's connecting down into the access layer in some fashion. 8 00:24.000 --> 00:29.150 And so this is one particular site. We'll call this the headquarters site. We 9 00:29.150 --> 00:34.000 might have an internet block that comes into this distribution block. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 9 00:29.150 --> 00:34.000 might have an internet block that comes into this distribution block. 10 00:34.000 --> 00:39.210 And so so far everything is working fine except then we have a second site 11 00:39.210 --> 00:40.000 added. 12 00:40.000 --> 00:44.790 Site number two is much smaller but it does have dedicated distribution and 13 00:44.790 --> 00:46.000 access blocks. 14 00:46.000 --> 00:50.560 So this is site two. And then we're bringing the distribution block into the 15 00:50.560 --> 00:52.000 other distribution block. 16 00:52.000 --> 00:57.220 So where is the core in this situation? Well the core is right here in the 17 00:57.220 --> 01:01.000 middle. We'll get rid of that D and we'll say hey we have collapsed. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 17 00:57.220 --> 01:01.000 middle. We'll get rid of that D and we'll say hey we have collapsed. 18 01:01.000 --> 01:05.910 Remember the functions of our core and the functions of our distribution block 19 01:05.910 --> 01:08.000 into a single set of hardware. 20 01:08.000 --> 01:15.000 So now we are switching back and forth among these different blocks here. 21 01:15.000 --> 01:19.900 And that means that we're doing some amount of core functionality. So I'll get 22 01:19.900 --> 01:22.000 so far and this is not a problem. 23 01:22.000 --> 01:26.330 But then we add another site. So now we have site three, another distribution 24 01:26.330 --> 01:28.000 block, another access block. 25 01:28.000 --> 01:33.000 And at some point here we might say all right maybe it does make sense for us WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 25 01:28.000 --> 01:33.000 And at some point here we might say all right maybe it does make sense for us 26 01:33.000 --> 01:39.000 to split off the core functions into its own dedicated hardware. 27 01:39.000 --> 01:45.140 The problem is when we're talking about performing this upgrade it's a little 28 01:45.140 --> 01:49.000 bit tricky to decide when exactly to perform this. 29 01:49.000 --> 01:54.130 How do we identify when it's time to split off and create this three tier model 30 01:54.130 --> 01:57.000 that we know we're capable of creating. 31 01:57.000 --> 02:01.360 What's going to help us make this decision is when we recognize exactly what WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 31 01:57.000 --> 02:01.360 What's going to help us make this decision is when we recognize exactly what 32 02:01.360 --> 02:04.000 the benefits are to performing this upgrade. 33 02:04.000 --> 02:06.610 Because we're going to need to justify this we're going to have to go out and 34 02:06.610 --> 02:08.000 purchase additional hardware. 35 02:08.000 --> 02:13.720 Justify this to our management team. And so if we understand the benefits then 36 02:13.720 --> 02:17.000 we can not only properly identify when it makes sense to do so. 37 02:17.000 --> 02:22.010 But we'll be able to get the money from our management in order to make that 38 02:22.010 --> 02:23.000 purchase. 39 02:23.000 --> 02:27.290 So what are some of the benefits to upgrading well first of all it's going to 40 02:27.290 --> 02:30.000 give us dedicated resources at each layer. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 41 02:30.000 --> 02:35.420 Right now our switching between let's say this distribution block over here and 42 02:35.420 --> 02:41.540 the internet this is going to be impacted by the relationship here between our 43 02:41.540 --> 02:43.000 distribution and access model. 44 02:43.000 --> 02:47.820 Meaning that if we have spanning tree protocol issues happening here then this 45 02:47.820 --> 02:50.000 traffic is going to get cut off. 46 02:50.000 --> 02:54.650 We might have a broadcast storm that impacts site to usability to directly 47 02:54.650 --> 02:56.000 access the internet. 48 02:56.000 --> 03:02.000 And so this is also going to help us create isolation of issues. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 48 02:56.000 --> 03:02.000 And so this is also going to help us create isolation of issues. 49 03:02.000 --> 03:06.330 This is something that can get overlooked a little bit because we have a layer 50 03:06.330 --> 03:09.000 to domain typically down to our access block. 51 03:09.000 --> 03:13.780 And so we could actually end up having broadcast storms and other spanning tree 52 03:13.780 --> 03:17.000 types of issues that will impact all of the sites. 53 03:17.000 --> 03:21.480 And if we have a dedicated core layer then we could have these same spanning 54 03:21.480 --> 03:26.000 tree protocol issues and yet the traffic between sites two and three in the 55 03:26.000 --> 03:28.000 internet would not be impacted. 56 03:28.000 --> 03:32.000 It's also going to allow us to create further scaling. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 56 03:28.000 --> 03:32.000 It's also going to allow us to create further scaling. 57 03:32.000 --> 03:37.280 And so as we scale out to sites four and five for example I mean that is a 58 03:37.280 --> 03:39.000 conversation point. 59 03:39.000 --> 03:43.000 Are we planning to deploy sites four and five is that in our future. 60 03:43.000 --> 03:46.960 If management says oh yeah we're going to be deploying more locations then this 61 03:46.960 --> 03:51.710 isolation conversation is going to be even more impactful because we don't want 62 03:51.710 --> 03:57.000 an issue at one location impacting the several locations all at once. 63 03:57.000 --> 04:01.840 So from there we do need to talk about also the process of upgrading and here's WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 63 03:57.000 --> 04:01.840 So from there we do need to talk about also the process of upgrading and here's 64 04:01.840 --> 04:03.000 the good news. 65 04:03.000 --> 04:10.280 The process of upgrading is going to be fairly simple because we have 66 04:10.280 --> 04:14.000 maintained our network model. 67 04:14.000 --> 04:19.000 Once again the model is not locked to physical network blocks. 68 04:19.000 --> 04:22.000 The model is locked to our functions. 69 04:22.000 --> 04:26.960 And so as long as we have identified our functions maybe we've deployed a 70 04:26.960 --> 04:32.000 routing protocol to make sure that the core side of things is working properly WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 70 04:26.960 --> 04:32.000 routing protocol to make sure that the core side of things is working properly 71 04:32.000 --> 04:35.100 throughout this whole process even though it's on the same hardware as the 72 04:35.100 --> 04:36.000 distribution block. 73 04:36.000 --> 04:40.500 If we're going to upgrade to a three tier model this isn't going to be all that 74 04:40.500 --> 04:41.000 bad. 75 04:41.000 --> 04:49.990 So what we would end up doing here is we would create a true core layer here. 76 04:49.990 --> 04:52.000 So now we have this as a core block. 77 04:52.000 --> 04:55.790 We would have to in some way make sure that we now have a distribution block 78 04:55.790 --> 04:57.000 here in the middle. 79 04:57.000 --> 05:02.770 We could probably repurpose our set of hardware to either go into the core or WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 79 04:57.000 --> 05:02.770 We could probably repurpose our set of hardware to either go into the core or 80 05:02.770 --> 05:04.000 the distribution. 81 05:04.000 --> 05:08.310 But the fact that we had these functions separated out in our own minds at a 82 05:08.310 --> 05:13.260 minimum and potentially from a configuration perspective this is going to allow 83 05:13.260 --> 05:16.000 us to very seamlessly perform this upgrade. 84 05:16.000 --> 05:22.000 So what type of violation of the model would make this more difficult? 85 05:22.000 --> 05:27.000 Well imagine if we had layer two extended from one site to another. 86 05:27.000 --> 05:32.500 Once we had the collapsed environment that would actually have been possible WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 86 05:27.000 --> 05:32.500 Once we had the collapsed environment that would actually have been possible 87 05:32.500 --> 05:38.000 and maybe something we did because this was collapsed core and distribution 88 05:38.000 --> 05:42.000 which means that we could extend a VLAN from one location to the other. 89 05:42.000 --> 05:46.500 Well now that we've split off the core and it's all layer three this would 90 05:46.500 --> 05:48.000 functionally break. 91 05:48.000 --> 05:52.650 So as long as again we're maintaining the model and the functions of the of 92 05:52.650 --> 05:57.000 that model it's going to make it so that we have a simple process. 93 05:57.000 --> 06:00.900 Otherwise if we have VLANs extended among all of these sites well that's going WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 93 05:57.000 --> 06:00.900 Otherwise if we have VLANs extended among all of these sites well that's going 94 06:00.900 --> 06:02.000 to be a big problem. 95 06:02.000 --> 06:05.580 It's going to take a while to perform that upgrade. We might even say it's just 96 06:05.580 --> 06:09.000 not worth the headache unfortunately at that point. 97 06:09.000 --> 06:13.180 So whether or not it's time to upgrade from a two tier model to a three tier 98 06:13.180 --> 06:16.000 model is going to depend on the organization. 99 06:16.000 --> 06:22.030 The focus should be on the benefits here and not only just from a network 100 06:22.030 --> 06:27.000 performance perspective because yeah we get some amount of performance 101 06:27.000 --> 06:28.000 improvement in all of this. 102 06:28.000 --> 06:32.310 Most organizations might say okay but the collapse design is serving us well WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 102 06:28.000 --> 06:32.310 Most organizations might say okay but the collapse design is serving us well 103 06:32.310 --> 06:33.000 enough. 104 06:33.000 --> 06:40.210 Well we also need to worry about how easy it is to troubleshoot this network 105 06:40.210 --> 06:43.000 and for that matter what happens when issues arise. 106 06:43.000 --> 06:48.610 Because the isolation issue can make it so that once again now as we said if 107 06:48.610 --> 06:54.260 there is a failure at one location like at the maybe the distribution layer of 108 06:54.260 --> 06:55.000 our headquarters site. 109 06:55.000 --> 07:02.010 Well now our other sites can continue to have conversations out to the internet WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 109 06:55.000 --> 07:02.010 Well now our other sites can continue to have conversations out to the internet 110 07:02.010 --> 07:07.180 and so it does isolate and make it so that we can lock in on issues very 111 07:07.180 --> 07:08.000 quickly, troubleshoot those. 112 07:08.000 --> 07:13.040 And hopefully ideally maintain better uptime along with better network 113 07:13.040 --> 07:15.000 performance.