Direct Attach Cable (DAC) vs Active Optical Cable (AOC) - Which Do I Need To Buy For My Rack?

[Applause] [Music] hi I'm John from UNIX Plus and today we're looking at our 10 gig direct attach cables and our AOC cables we're going to look at some of the differences on them and which one you're going to want to use in Iraq we're going to end this video up with a shot of a messy rag and how not to mag iraq and how you can manage it with each different product so come with me and let's take a look at different DAC cables so there's a few different for cable formats SFP+ q SF v and now SP 28 and let's talk a little about those different things and how they influence the NSF P+ historically is a small form factor optic that came in in the time of one gigabyte and is now upgraded in this form factor to 10 gig it's a nice little form factor that's the exact same size as a standard LC little connector which gives you an optic fiber pair because these were optics originally started out expensive they came out with the DAC cable this DAC cable here is made by Arista it's an OEM cable it's a 1 meter long cable it's about 3 feet long and this here is a nice thin original Arista cable we also have a one meter Cisco cable to show you the comparison this is a Cisco original and then our own UNIX Plus product you can see is nearly identical still has the same velcro zip ties in fact it has two of them one and it's the same length in the same gauge of copper you can see how it bends and loops you never want to kink one of these data cables because if you were to put a 90 degree bend in the cable it's a shielded cable you're going to actually change the impedance and you're going to could possibly damage the signal integrity of each cable pair the way that an SFP+ works versus your standard rj45 an rj45 was trying to transmit across twisted pairs that pair is a differential pair of two signals that is going in and you do a difference between the two signals the impedance and the noise of a telephone pair of cable is certainly known anybody that used to use a wired telephone would con you find out when it rained you had a bad connection if you're as old as I am but maybe you don't see that so much anymore but that's because your twisted pair only had so much signal integrity in so much bandwidth so they've got this thing up to about 350 megahertz and cat6 e and they run for parallel and that's how you can get to a 10 gig over rj45 copper but that's pretty much the end of life the other SFP+ cable versus optical and other things has a lot less loss because from this connector to this connector you completely control the signal integrity so these things with this particular cable you're able to run over 500 megahertz over a differential pair you also have shielding on your cable too which makes the difference that allows you to go those high speed and you reject anybody else's noise or talking so to start the started out with SFP which is one gig interface there's SFPD X came back from the fiber channel days one two Gigabit Ethernet now there's sfp+ a 10 gig and now there's SFP 28 SFP 28 is the new spec that uses the exact same connectors but it runs a 25 and 50 gig so that's going to allow you to go into a cue SFP 28 which is 4 channels so it's 4 of these cables in one connector and that cue SFP 28 is going to be your new cabling standard for 100 gig networking so let's talk a little bit about the gauge of copper and what makes a @ DAC cable different if you're going to be running between one two and maybe three meters you're going to be in a lower gage of copper that means you have thinner copper that's more flexible and not quite as thick if you're going to run over three meters typically a lot of companies we're going over to the AOC this is a sfp+ AOC product that we right here we have a 1 meter dak versus an AOC cable you can see that the AOC cable is a little thinner than the 1 meter deck it's also a little bit more flexible than the DAC cable you can see that it bends a little bit better you can loop it up a little bit easier and your loops won't take as much space when you get into like a 5 meter q SFP like this is regarding you can see how thick this cable is and how little bit it bends so it's going to become a real nightmare if you were to fill your whole rack with all of these switches right here you put in your Q SFPs with your big hunk of chunk of cables coming out and then you have all this stuff looped up as an extra how many more ports am I going to be able to take when you have 32 of these compare that to Q SF p k LC you're going to find that you can still keep a lot of these cables in here hooked up with just small loops attached to a security bar so a lot of customers right now are going to choose to spend a little bit more on an AOC DAC cable inside the rack versus a higher gage or longer sfp+ typically sfp+ breakouts are also an option if you go to this Q SFP here you see that you have a long cable here too for sfp+ cables that you could run into any switch again this is under one meter in length so each of your small little cables here comes out to a small back cable that's about the same thickness so if you're going to be cabling up a rack and you're interested in trying to keep your cables nice in the backside you're probably going to want to order a mix of 1 meter 2 meter then three meters typically three meters about is where the customers start to choose to move into a LC versus copper cable you can tell the difference of this bending and all this type of cut you're going to have this type of density on your qsf PS especially the thicker gauge cable the heavier cable is just going to mean that you're going to have a lot more of inflexibility in the back of your rack each one of these is as thick as a power cord and stiffer what you're looking at this particular option it's very flexible and in a OSE is even more flexible as far as cable routing aoc is an active optic cable that is the same as these particular transceivers with a cable that you just can't remove why is that good well it's less cables to track and less cables to unplug it allows you to go the same distance and typically it's about the same price this here is a 3 meter DAC as to optical transceivers maybe a little bit less so where is the value of going with DAC vs. AOC or optics if you're going to buy two optics at $30 and then run a particular cable you have the ability to each cable to come loose or different particular reasons for reliability if you don't want to run those cables you have two different tables and by three ports it gets a little complicated but still you're under that 60 70 buck if you use a DAC cable they're running between twenty-five and thirty dollars right now so you're nearly half the cost so DAC cables are typically used inside your rack to talk to any of the 10 gig switches like this one here so let's take a look at what the negatives of back tables are if you start working with a lot of DAC tables they're kind of thick and the back of your act quickly becomes looking like this this is a bad example of an additive system where these servers were added in post off of these servers and more 10-gig ports ride again one of the critical things to do with that cables as you're going to enforce some form of loop cable management you don't want to put large Nick's in the cable however you can pull off cable in this manner and then velcro tie it together in a female type of competition these rules in terms of no networks allow you to keep your cables clean enough so that you can work with an additive and you avoid this rat's nest situation there's a lot of cable management products like this vertical arm that just mount on any server market marketing right here after your mountings here you'd be able about throwing zip ties to these cables if you need to typically we recommend velcro any type of zip tie there's other horizontal cable management's this one's from a PC UPS's that would come over here and allow you again to tie into the rack one of the considerations when you order a lot of 2 meter cables like this you're going to generate a lot of loops so you either need to come out horizontal for a horizontal cable management and tie with 2 meters or use one meters and look 1 meter in there it's really important when you order your racks and you order your cables to consider your rack layout with this with back cables if you use one meter from this middle row section here you'll be fine you'll be able to put the list together and you won't have any problems if you use 2 meter you'll be able to pretty much go from the middle to the side to the gallon if you're to use 3 meter length you'd go from the top bottom over in the top however you're going to have to stagger the lengths of your cables for the top switch locations you'd use for the first third you use a one meter for the second third you use a two liter for the bottom third you were to use a three meter cable that will give you enough length come up there the liability of DAC is these large loop of thick cable of different lengths that become a rat's nest situation like this rack here so this is an example of how not to wire your DAC cable so thanks for watching our video on AO sense and DAC cables you have any questions our sales reps would be happy to help you out you can subscribe to our Channel or you can reach us in a time at 877 UNIX one two three or eat to visit our websites in UNIX plus or UNIX surplus calm thanks for watching you

Channel: UNIXPlus Wholesale Distributor

Views: 38,188

Rating: 4.8264461 out of 5

Keywords: DAC, AOC, Direct Attach Cable, Active Optical Cable, 40G, QSFP+, 10G, SFP+, AOC-Q-Q-40G-3M, networking, switch, cable management, arista, cisco, 100G, 1G, 25G, qsfp, sfp

Id: ACTMTHg-FVk

Length: 11min 10sec (670 seconds)

Published: Mon Jan 09 2017