Why the Dell S5148F-ON is a cheaper 25/100GbE Switch

hey guys this is patrick from sth and today we're going to talk about the dell networking s 5148 f-o-n and some of the relevant bits that you need to know about that model name are the fact that it's a dell emc switch and it uses their dell os 10 for their networking software so that's kind of cool too it's also that one in the 51 means that it is their you know that's the generation number 48 means that we get 48 25 gig ethernet ports and then on frankly means that it's open networking now this switch is not a new switch by any stretch of the imagination in fact i think that the switch actually came out in like something like may of 2017. and ever since the switch came out it's become somewhat of an interesting switch to look at and that's kind of why i thought well maybe i'd go get one actually too and go tear them apart and so we can go look at them and see what makes them tick the reason that's super important is because some of the hardware choices that dell made in 2017 which were perfectly reasonable back then have kind of meant that this switch has a very different spot in the market than when it launched and i think it may be worth taking a look at these days because it's actually a pretty inexpensive switch to give you some sense if you look on something like ebay and you just go search for the dell s 5148 fo n what you're probably going to find is a number of listings some not even just in the u.s but also some inventory in europe where you typically will see prices maybe in the 1300 to 1600 range on a very regular basis for that price it's pretty awesome now yeah i know what you're thinking patrick it's been a long time since you've done a high-end switch and this is actually kind of not even a really high-end switch not even a 32-port 100 gig ethernet switch well just for that we have oh boy we have this which will probably be the next switch that we review which is a 100 gig ethernet dell switch and so this is actually the s 5200 series so before you know we did this video on the s5100 series we actually have a couple now of the s5200 series and we can go and tear those if you want please leave a note in the comments section if you want to go see inside one of these switches because i think it might be kind of cool just to go and see inside of them because dell doesn't really publish that so the basic game plan for today we're going to take a look at the hardware talk about what some of those hardware choices are and why i think that they actually are depressing the price of these switches on the secondary market and you can also talk a little bit about the next generation that followed and why i think that's actually a better switch but we're gonna go through the hardware and just kind of talk about some of those aspects and then what we're going to do is we're going to talk a little bit about environmentals and you know power consumption some of the management aspects to it and then really the software side which i think is also important we're going to talk a little bit about that during the hardware side but we also want to just talk about software and why i think they're actually an okay value these days however there are also little bits that you may want to look for and i'm going to highlight those as well so with that let's get over to the hardware okay so let's take a look at the front of the switch because that's probably the easiest part first thing that you're going to see is a stacking number so that's your stack id and then what you're going to see is a total of 48 sfp 28 ports now sfp 28 is what allows you to go run 25 gig ethernet optics or dax on these ports but one thing i do want to just mention really briefly here is that if you have 48 optics and even if you're only paying say 20 dollars per optic well that's not necessarily inexpensive itself you're talking about almost 1 000 just for the optics for the switch and then you know you have the qsfp optics and so your your basic thing is that even if you get this switch for in that you know maybe 14 1500 range you're still gonna spend another over a thousand dollars most likely on the optics for the switch so the actual cost of the switch is only part of the equation in this whole thing i just want to make sure that everybody has that and keeps that in mind as we're going through this now i mentioned that this also has 100 gig ethernet and there are six qsfp28 ports on the front on the right hand of the chassis typically what you would use these for is linking multiple switches together and so they can be used for stacking or they can be used just to go connects to say a 100 gig ethernet switch but if you do have a smaller network topology and maybe you only have one or two switches they could also be used for something as easy as they could actually be hundred gig ethernet connections to psych storage servers or virtualization servers whatever you need you actually have some higher speed ports there as well now i mentioned the fact already about the optics and we are doing a giant series on sth around fiber optic networking so definitely check out the sdh main site for that we recently did a video on looking at plenum cable and talking about what plenum cable is and so you can look at that on youtube but for the rest of it we're probably going to have most of it on the sth main site except for maybe the install videos aside from the optics though you can also use dax and decks tend to lower the cost of connecting devices significantly we buy a lot of our dax for maybe 20 or so so if you're just going inside of a rack using a dac which is a you know direct attached copper cable basically has two ends that are say sfp 28 or qsfp 28 ends and you basically just connect those into say your server and your switch and then you don't have to go buy two optics plus the fiber optic cable that goes between them they also tend to be lower power so you tend to have lower power and lower cost and so that makes stacks a total win if you can use them now this is a very high end switch and so we do have hot swap fan modules if you do get lower end switches a lot of times that's a feature that you'll see fixed fans but in this class of switch you pretty much have to have a hot swap fan array now on either side of the switch what you have is redundant 750 watt dell power supplies this switch does use a fair amount of power and it can use several hundred watts and so it is important that you have you know a a power supply that can power the entire switch and because you also want to make sure the switch doesn't go down if power goes down then you also need redundant power and so it's another area where this really just that is just kind of standard for this class of switch that you have two power supplies and this does now in the middle of the switch we have a couple of features that are in this little block and this little block has a usb port it has a service tag and also has a serial port and a management port you have a serial port which the serial console is just kind of a standard interface on switches and then you have a management port now this management port can give you one gig ethernet and you can go say run that one gig ethernet and that could be your out-of-band management to the service processor which is really the rangely processor the intel processor that's on this so the basic idea is that on the front of the switch you have all the networking ports that are kind of like primary data ports but then on the rear you pretty much have your cooling you have your power supplies and you also have all the management bits that you need they're not kind of directly in that data path now again the whole admin management is just standard on this class of switch and this kind of configuration is standard what is not necessarily standard is the fact that these things are on the rear of the chassis and so i just kind of like it better when like some of this stuff is actually on the front of the chassis the management port sure serial port maybe that can be in the back but in terms of like the usb port and also the service tag i really kind of wish that those were on the front okay now looking inside the switch the big heatsink let's talk about that first because that's kind of what everybody wants to know about in this switch the switch ship powering this is the cavium expliant line now a little bit of history here is super important to understand what's going on with this switch so explain was a cavium product and cavium was eventually purchased by marvel and then marvel just recently decided hey um actually instead of going with kind explain as our kind of real next-gen high-end infrastructure we're going to do instead or chip we're going to do instead is we're going to move to inovium so they just purchased the novium we did a review and a teardown of a 400 gigabit ethernet 32 port inovium switch before they were acquired and so if you want to go check that out that'll be on youtube we'll link that in the description as well but the basic thing here is that if you look at switch chips and just merchant silicon in general for open networking pretty much broadcom is the biggest vendor by a long shot i mean they're just by far the 800 pound gorilla in the space so dell choosing x-plane here was basically a look at something that you know they probably got a deal maybe on and so maybe it's a little bit lower cost but still a nice chip but at the same time um you know it's just not as widely used in the industry you'll also notice that there's a celestica board with a micro chip or actually this is marked to micro semi but now microchip they have a zl3363 and that is a network synchronizer board moving behind that what we actually have is the main management processor board which basically looks like this because well i just pulled it out first we have an innodisc 16 gigabyte msata ssd and that's really for you know our network operating system and all that kind of stuff you also see that there are two memory modules maybe to be more clear there are two memory slots and these are really designed for ddr3 so dimms we only have one so dim installed and that's an eight gigabyte model i typically don't try to upgrade the memory on these switches because i just don't need it ever but i guess if you really wanted to maybe that's something you could look into clearly that second sodim slot is there for a reason now you might be thinking to yourself wait a sec ddr3 that feels like it's a little bit old and that brings us to the next most interesting part of this solution which is really this service processor right here under this little heatsink what you actually have is an intel atom c2000 series rangeley processor now at sth we covered the launch of rangeley i think that was like in september 2013 or something like that it is definitely at the very end or towards the end of the embedded product lifecycle usually you have at least seven years or so so you know it's 2021 that is definitely an older part at this point but rangeley was actually famous for another feature or maybe not necessarily good feature and that specifically was the fact that rangeley had the avr-54 bug now if you don't know what the avr54 bug is pretty much the short version is that the intel atom c2000 series so there are two code names there's avatin and rangeley this is rangeley but the atom c2000 series you know was basically an awesome low power x86 processor that people put in things just like this switch which you can see here right and so there are a lot of companies that design these in and it wasn't just dell by the way i mean this was you know pretty much everybody in fact the actual avr-54 bug was found by cisco another networking company and it specifically caused a lot of angst in the industry now on the sth main site we will link this in the description but we actually kind of talked about well hey there is this avr-54 bug and not only is there this avr-54 bug but intel actually made a fund to go help vendors go and fix their products but it also managed to go and say like hey vendors you get access to that money but only if you don't tell people that it was us that had the issue and the very high level version of what the avr-54 bug was was that there was a bug in the silicon that at some point would basically wear out a particular circuit and then what would happen is you would say reboot your device whether that was a firewall a switch whatever it was you reboot your device and it would just fail to start up and it would basically brick whatever device that was so the reason a lot of people may know that is because this caused all kinds of problems i mean imagine if you had hundreds of switches thousands of switches if they were deployed at edge locations all the heck over the place and then you have to go have you know your your switches your firewalls all that kind of stuff has to go be replaced as part of a you know return process so that way you can get an updated version that wouldn't just you know die at some point and it was a particularly interesting bug because it didn't necessarily happen in the early life span but it's really like after maybe like 18 to 36 months that these kind of failures would start to happen at sth we actually had a firewall that hit this and we actually have seen it now in two different systems more from like the 2013-2014 era so there are older systems but the same time we have definitely seen it and so the atom c2000 series has a bit of a reputation as you know it can cause a lot of headaches when these devices break now on that though the important thing here is the fact that these switches were actually released i think in may of 2017. there's a stepping change that came out in april 2017 which would have been before this but these switches if you got it like a really early like may june 1 you probably wouldn't have gotten the new stepping but you may have gotten something like the rework chip so we've actually had a couple of these switches running for the last like three and a half years in one of the sth labs and we haven't seen any issues with them but we don't have a really big sample size so i can't tell you like this is definitely everything's gonna be 100 fixed but on the other hand you know if you found one that you know was produced in something like late 2018 or late 2017 early 2018 something like that i would think that by then these would definitely all be reworked and because nobody nobody would want to go and put out a new switch that didn't have the rework at that point because you pretty much knew that you're going to have a rma claim on it and it was going to cost a ton of money to go fix right so like so i i do think that these switches even though they have the atom c2000 series which used to be like a ticking time bomb if you had an older generation product these ones actually came out at a period where it was probably after everybody you know dell would definitely have known about it before these came out and i would just kind of assume that most of these would have either the workaround rework or they would have a new stepping depending on when they came out but just the fact that it has that explain switch plus it has this range of thing i think it's a reason that this is a lot less expensive one other kind of interesting note here is just the fact that the rear connector on this and how this actually seats into the bottom board is that there's actually kind of a really cool little high density connector here and one other little tidbit in the event that you're worried like hey this is an x86 only switch the management plane is x86 but you may have seen the fact that there is an arm processor on here which is right here this is an aktel smart fusion chip and just in case this is not the thing that you're going to be running os 10 on the main processor that you're going to you know kind of use for management is the rangeley processor not this one so just let's be very clear on that now the management board doesn't connect directly to the switchboard instead the management board actually connects to the board that handles things like the power input so you have the power redund power supplies that go into this power distribution board and you also have things like the hot swap fans that go into that board as well plus all those management ports if you remember they're in the rear of the chassis well it just happens to be on the same side as the management processor which sits towards the rear of the chassis as well one thing that i looked at i was like wow that is like i do not like that design at all is the fact that the battery for this device which is a cr2032 battery actually sits below the management board and on that kind of power distribution board now you might be able to get in there and actually go pull it off but i think most people if you're going to go replace that well you're probably going to have to go and actually you know pull this board off and pull this out so you can actually get into that battery to go replace it now in terms of power consumption we do have 750 watt power supplies uh realistically we're running these things in a couple hundred watts we're not really getting anything under 200 watts by any means but even with some optics and stuff like that we tend to be running these in the 400-ish watt range so that's kind of just something that you can kind of budget towards but there's a very wide range depending on how many ports you're using how much traffic you're passing what you're doing with the switch chip uh you know if you have optics or dac some kind of optics you have there's a pretty wide range in terms of what you can get in terms of power consumption so we're going to say maybe go look at the spec sheet kind of figure out what you think you're going to use in terms of you know connectivity and how much you're going to use the switch and maybe that'll kind of help guide your decisions a little bit better now dell does not do a really good job in terms of you know showing internals of these switches they do a really good job of even just documenting like what the processor number is or you know what the switch chip actually is in these devices to me i think that's a total bummer because if you're trying to look up these things after the fact it's actually kind of hard to figure it out and if anything that atom c2000 avr 54 bug really taught us the fact that it is important to know what kind of chip you have in there especially if there's some kind of vulnerability or some kind of issue with a set of chips it's important that you know what you have installed so that way you know if you're impacted by a bug that's found later down the line so as dell moves into the open networking era i really think that it would be awesome if they just started you know publishing full spec sheets and not leaving that kind of information out but to me the number one most interesting part of this is really the reason that i think that this is a much lower cost switch and i don't necessarily think it's a lower cost switch because just because it's a 2017 like mid 2017 era switch i actually think that the combination of the rangeley management processor plus the explained switch chip is the real reason that this switch costs a lot less than a lot of its contemporaries and the reason for that is that let's just kind of go look at some of these support pages for two popular network operating systems so if you didn't want to use dell os10 and you wanted to go use something that was more in line with like other open networking types of operating systems you might go over to sonic sonic is the big open networking thing that a lot of the hyperscalers are doing and a lot of enterprises are looking at it because they're like hey this this is actually something i want to go and deploy and so when you look at sonic and you look at the support you will see that there is a lot of stuff there for the s 5200 on but there is not a s 5100 on chip there or switch there and the reason for that is because this is based on the expliant rather than the broadcom product so that switch chip is kind of a big deal and it's not just sonic which would probably be the big operating system that you'd want to run um if you didn't want to run os x on this but also if you're to look at something like cumulus linux well that is now owned by nvidia and when you go look at that you also don't see support for the switch so without being on those very specific hardware compatibility lists i think that that is a big reason that you don't necessarily see this switch fetching the same price as some of the contemporaries or even just you know the next generation of chips where they were dell switched from expliant to broadcom but that also might present an opportunity because the switch is readily available not necessarily super expensive and you know if you're okay running dell os 10 and the switch has a license for os10 on it then maybe it's actually a pretty inexpensive way to get into a fairly high port count 48 port switch and also get six 100 gig ethernet ports if you're thinking like hey can i go put this next to my desk at home do not do that this is still a you know very hot one-use switch it uses a lot of power it is not something i would want to go and have next to me absolutely screams but at the same time i think that if you do have a data closet or maybe you know somewhere at work or something like that where you might need a very very low cost 25 or 100 gig ethernet solution this might be a very good option so long as you're okay running os 10 but i hope you liked this little teardown of the switch and if you did why don't you give us a like click subscribe turn on those notifications so you can see whenever we come out with great new videos as always thanks for watching and have an awesome day

Channel: ServeTheHome

Views: 43,468

Keywords: Dell, Dell Networking, Network Switch, 25GbE switch, 100GbE Switch, 48-port switch, Dell EMC, SFP28, QSFP28, Marvell, Cavium, Broadcom, XPliant, Intel, Atom C2000, atom c2000 bug, Rangeley, Dell S5148F-ON, S5148F-ON, dell s5148, dell s5148 switch

Id: QHipTq2sitA

Length: 19min 35sec (1175 seconds)

Published: Sun Sep 19 2021