On the verge of replacing my copper for fibre, and this pops up. Thumbs up and comment for the mighty algorithm, and a genuine salute from me for an informative and helpful video!

@LAWRENCESYSTEMS

2 жыл бұрын

Thanks!

In case you want to know why it's called SFP28: It's because it does technically have 28 Gbit/s of *bandwidth*. But after encoding, you're only left with 25 Gbit/s of *data rate*. Same with QSFP28 and QSFP56, btw. As for the inconsistent naming, I assume (and that's just an educated guess) it went something like this: Once upon a time, there was this thing called SFP. It was the only member of the SFP-"Family", and so didn't need any way to differentiate itself against, well, nothing. Then came a new thing. It had the same interface as SFP, but it was faster. How to name it, so people know it's compatible, but different thoug... How about SFP+? Y'know, 'cause it's SFP, but better. Yay! Then came another new thing that was better yet, but still had the same interface. Hm... SFP++? Nah, can't just keep tacking on pluses at the end, it just gets ridiculous. And it looks like SFP's here to stay, so there's likely gonna be more in the future... Oh, I know, let's just tack the speed at the end instead, that'll be a unique identifier for all the new ones that are yet to come! But we can't go back and rename the other ones now, people already know them by those names. Oh well, guess we'll just have to live with two names that don't fit the pattern... As to why the (in practice usually irrelevant) bandwidth was chosen rather than the data rate, I don't know.

@BlackbeardedPirate

2 жыл бұрын

Similar route as USB I guess :) What's better than USB 3.0? I know lets call it 3.1 Gen 2 and rename the old 3.0 to 3.1 Gen 1. Ok, sounds like a plan. But what if we develop something even faster? Easy, we'll rename the old 3.1 Gen 2 to 3.2 Gen 2 and the faster one to 3.2 Gen 2x2 Still with me? To make all of this easy we're going to use just one port to rule them all, but the cables won't be compatible, cause that would be weird.

@andyrandy0815

2 жыл бұрын

Nice explanation

@MichaelShor

2 жыл бұрын

@@BlackbeardedPirate Then you have USB 95 and USB 2000, and the bastard cousin, USB Millenium Edition, that basically end up with electric shocks and lost data?

@tenoki

Жыл бұрын

@@BlackbeardedPirate I was just trying to explain this to someone upgrading from an "Ancient" computer with USB 2.0. Then he started asking if he needed Thunderbolt and what the differences between Thunderbolt 4 and USB 4... *I think I need a gallon of water for this one*

@jdbrinton

Жыл бұрын

except to make things even more complicated, after encoding, 25G ethernet transmits at 25.78125Gbps, not 28Gbps.

Upgrading our access layer and aggregated core stack in our MDF and have been loving the simplicity of DAC cables! Using them for interconnectivity passing 10 gigabits.

Did the USB guys name SFP28? Probably not, they would've named it SFP 4.2 3x3 or something dumb.

@ivosarak959

2 жыл бұрын

That number is a single channel bandwidth indicator and it is to make life easier for the naming. QSFP is 4-channel 10Gbps bundle, to get 56Gbps you need a 2-channel bundle of a 28Gbps, 100Gbps is 4-channel and even more exotic speeds and variants on top of it. Channel can be formed per fiber strand or by different wavelength set within single strand.

@rjdp3

2 жыл бұрын

Wait for the SFP128 that works at 100G 😅

@timramich

Жыл бұрын

@@rjdp3 100 gbit comes in QSFP form as QSFP28. It also comes in SFP-DD, although I wouldn't see a point when QSFP28 exists. QSFP56 is 200 gbit and QSFP-DD is 400 gbit. Not sure how 800 gbit is also QSFP-DD.

Great info, I'd always hoped for more clarity around all those DAC looking cables but hadn't dove deep enough down the rabbit hole to find out for myself 👍

@pepeshopping

2 жыл бұрын

Google is really great for passive/slow people like you.

Another good thing about AOC cables is they meet Tempest specs if you work in Government or Classified networks where multiple classifications are in one datacenter and they will not let copper cabling cross across racks at all

@SunbrightShinobi

2 жыл бұрын

@Conor Hanley not really as its a different type of media. its more like comparison of using optical output from tv so surround sound for digital audio stream compare to a single copper wire for each speaker signal. You can interchange the two like a cheap to a high class cable. if my understanding out "hi-fi audiophile cables" is the same as yours

Another very informative video. I think a video on proper rack/equipment grounding and lightning surge protection would be great too. I'm sure there's plenty of us out here that have taken 1.21 gigawatts through a WAN port that let the smoke out of our racks! This is what's pushed me into adding fiber into my rack to electrically isolate my modem from my pfsense box and the rest of the rack.

@Dextermorga

2 жыл бұрын

Great idea

@Vinothmanick

2 жыл бұрын

We usually do that for all our RF towers to routers to avoid frying up routers but we also have a grounding and surge protector

@Chad_at_Big_CAT_Networking

2 жыл бұрын

​@@Vinothmanick The problem with surge protectors is most people don't realize how they work and that the gas tubes inside them degrade over time. So you could have a high end UPS that you thought was going to keep you safe until you find out that the gas tubes are gone and it's not offering you any protection. What do you do about things like my 5 port PoE switch that only plugs in DC and doesn't have any kind of grounding on the case? All of this kind of rolls into a how to properly and safely power your equipment theme that I haven't really seen covered well anywhere.

@brentgreeff1115

2 жыл бұрын

@@Chad_at_Big_CAT_Networking - I am figuring out my first network & its not even something I considered.

@Shuroii

Жыл бұрын

@@Chad_at_Big_CAT_Networking manually route a grounding wire and ground the case of the switch by using a grounding screw or something, it's absolutely terrifying (for someone who doesn't know if it works) and looks ugly as hell but it works perfectly

Lifesaver, I was just fussing with this exact issue.

I've noticed negotiation issues with the EdgeSwitch 16 XG where they randomly don't negotiate or will only work at 1Gbps but only ever seems to be their own RJ45 10G SFP modules that this happens with.

what made Ethernet/RJ-45 so great was it just worked. even with the wrong speed cable it would still work. all these transceiver/DAC based systems use proprietary equipment and if you buy the wrong brand transceiver, or DAC/AOC cables, your screwed. and it's not like there are only 2 or 3 choices, there's DOZENS, and they rarely work together.

SFP28 vs 25Gb: So a few things to note here. 1) Ethernet measures it's speed before the CRC overhead, so a 25Gb connection is actually transmitting more than 25Gb "over the wire" so to speak, but the CRC overhead isn't counted. I think it's like 25.6 last time I searched this up. 2) Fibre Channel networks have been using names which are largely marketing only for a few generations now. So 32 "Gig" FC is actually 3200MB/s and after CRC overhead uses around 28.1 Gbps (really not bits, but whatever). 3) Because these were so close together, the Ethernet geeks and the FC geeks decided to team up and have 1 standard they could both follow for some of the cabling and connectors and such. So to summarize, the SFP28 standard can handle up to 28Gbps (Gigatransfers really). The Fibre Channel folks use this at 28.1 for "32 Gig" FC The Ethernet folks use this at 25.6 for "25 Gig" Eth And as someone else mentioned, MOST commodity 100Gb these days is 4 lanes of 25Gb being aggregated at the ASIC level. FC Similarly offers, within the 32 Gig spec, a 128 Gig trunk port option which is similarly just 4 lanes of "32 Gig". Often used for connecting larger FC SAN Edge switches to a Core (what Brocade would call a Director class) FC Switch.

@Casper042

2 жыл бұрын

Oh, and SFP56 is already a thing now too, and you guessed it, same physical socket size as it's predecessors. This is 1 lane of 50 on a family of 200Gb switches that started arriving in 2021, or I think Aruba has a switch with SFP56 Uplinks.

Unifi Aggravation Switch? Perfect!!!

Since I'm a big audiophile, I got so confused with "Why you need DAC in your rack". Now I get what you meant XD

@bobbuilder3748

Жыл бұрын

Thanks for the laugh.🤣

I use DAC where possible... I've stressed LATENCY loss for CAT for years. DAC is so simple, fast, and basically is like connecting two switches together to be the SAME switch when latency is concerned... so like having it as just a second daughterboard and another row of ports on the same switch. If you attach two switches via CAT/RJ45, you have massive latency loss between nodes across switches. For distances, running fiber with SFP+ adapters is the next best option. but same rack, I use DAC to connect all network equipment and even put SFP+ ports on my servers that are 10gig+ to use DAC for all servers to switches to make latency even lower to node.

i have on dl380 that im gonna use as a storage machine (and some vm's). and i want to connect it to my R630. Would a dac be the best machine to machine connection for file transfers? i also have spare 1G ports (no 10gb port on this device). Is it worth the price of 2cards, cable

What will be your best setup. I have 2 switches. One in house one in the barn but both has 24 devices and camer's 4k What will you setup be ?

Love your videos. Always watching everything you have, David Bombal, NetworkChuck, you name it. Just finished a CompTIA Net+, Sec+, and CCNA courses through the VA at an IT school for Veterans. Have applied to over 115 jobs in the past 2 months. Can't get a job anywhere. Everyone wants you to have a PHD for an entry level IT job. It's depressing and discouraging out here! So desperate for someone in IT somewhere to give me a chance to get started. Can't get a job without experience, can't get experience without a job. Yay.

@BrittanyGates

Жыл бұрын

Have you tried looking at working a Network Operations Center (NOC) at a cable company? It will give you the networking experience you need to grow your career, however you may have to work the night or weekend shift. Also, look at web hosting companies as they can use network engineers too. I hope this helps!

Ubiquity is crap on auto negotiation with SFP+. When I first got my units I had a hell of a time until I stopped letting auto negotiation do its thing.

Im running proxmox and truenas, both with intel x520. Using iperf im only getting 2.5g when truenas is the server and proxmox as the client. When doing Proxmox as the server and truenas as the client, it goes to 3.5g. I have set both MTU to 9000 on both machines. I have tried 2 different DAC cables, no change. Can someone please push me in the right direction to trouble shoot this issue and get full 10g.

Does anyone know which DAC works between UDM Pro and Aruba S2500?

"Aggravation Switch" - nice

Copper cables can have higher error rates than fiber; best not to use any kind of copper for FCoE or ISCSI traffic in a high performance environment unless you want to be defenestrated by the storage admin(s). AOC might work, but it’s unlikely the storage/server hardware is the same brand as the switch unless you’re in a UCS shop, which brings us to the second issue with these cables. Any kind of DAC/AOC may be problematic if the devices they are plugged into are from different vendors. They all seem to play the “you have to use our cables” game, and in a mixed environment, you should use the proper vendor-supported transceivers (with matching standards) at either end with the appropriate fiber type between. Otherwise, you may hit a wall when you need to get vendor support for the non-matching device.

Interesting. I have a Unifi 150-8 PoE switch and currently connected to a Cisco Catalyst 1000 via a copper SFP. Would there be any advantage of switching over to DAC to further reduce the latency? Just curious.

@LAWRENCESYSTEMS

2 жыл бұрын

DAC is fasted than RJ45, but only a few nanoseconds.

How does AOC compare to modular fiber in terms of latency? I don’t assume it’s in the passive DAC ballpark, right?

@ivosarak959

2 жыл бұрын

It is stated as less than regular connector variants, but the signal conversion between electric and light will not let it competr DAC.

UNIFI ***AGGRAVATION*** SWITCH STUDIO. Love that switch name 😂

@LAWRENCESYSTEMS

2 жыл бұрын

😎

One other advantage of AOC is that it's often cheaper then buying the modules and fiber separately.

@jamess1787

2 жыл бұрын

But the cable management is awful!!!! At least with fiber you have more choices for length, DAC seems like only a few options for lengths.

@pepeshopping

2 жыл бұрын

It is not!!

Technically, regular SFP is 1,25Gbps. 28 accounts for the overhead. Yeah I know, it still doesn't make sense because they didn't call regular SFP 1,25.

I think that 28 Gbps is max linkrate. Ethernet is just using it as 25. But for custom FPGA stuff 28 Gbps is max linkspeed for some generation of devices. Now they have 56 Gbps links but these are PAM4 coded. So symbol rate is still 28GSps

Just 2 weeks ago, the cheapest SFP+ were fiber transponders and good quality fiber. There. I will get DAC too but it really makes NO DIFFERENCE at all for MOST!

Do the fibre cables have the minimum bend radius like they used to or is that not as important (relatively speaking) as it once was or used to be?

@ivosarak959

2 жыл бұрын

It is still there.

@ewenchan1239

2 жыл бұрын

@@ivosarak959 Would you happen to know what the minimum bend radii are for the different types of fibre cables?

I don't negotiate with my traffic

I think the naming convention of sfp28 is modeled after its bigger brother qsfp28 which is 100gb

@timramich

Жыл бұрын

They both came at the same time. QSFP is just 4 SFP connections in one. Just like SFP+ and QSFP+. I don't think there was a QSFP (4 gbit)

Would you recomment cat8 over SFP+28?

@LAWRENCESYSTEMS

Жыл бұрын

No

@jonneymendoza

Жыл бұрын

@@LAWRENCESYSTEMS ahh ok. But price wise cat 8 seems way more cheaper than sfp 28. I'm asking as I am planning to future proof my house with at least 20gbit connection

@estusflask982

Жыл бұрын

@@jonneymendoza Run fiber, surely you're not talking about running DAC cables in your walls

@jonneymendoza

Жыл бұрын

@@estusflask982 no lac fibre om3 cables

They named it SFP28 because its transmission rate can reach 28Gbps, but I completely agree they should have just called it SFP25 since its not like we are going to get 28Gbps switching ports lol

@BigRonRN18

2 жыл бұрын

Did they overshoot 25 Gbps in hopes of not providing false expectations like we saw with Ethernet cables on 10/100/1000, where you seldom actually see the advertised speed? In my home network, I see speeds of around 970 Mbps on my 1 Gbps network. I'd rather it be CAPABLE of faster than advertised than of it being just a theoretical speed.

@ivosarak959

2 жыл бұрын

Protocol overhead is listed within that 28Gbps.

The new Desk feels a bit crammed. It is a good streaming/vlog Desktop but doesn’t feel studio presentation anymore

Ah yes, the aggravation switch. I to have had switches like that. Best thing, leave them and find a new one.

@LAWRENCESYSTEMS

2 жыл бұрын

Many switches are aggravation ones. 😂

first

Wow. Before speaking check: Are you SURE THAT DAC signals are NOT DIFFERENTIAL? That’s the difference between almost college and no college at all! Want to know the specific coding they use??? If you knew any electronics you would have never said that…

@LAWRENCESYSTEMS

2 жыл бұрын

I said it does not do "THOSE" differentials as in it does them differently and uses simpler method. But please keep being pedantic as it helps with KZread engagement. 😎