QSFP28 to female SFP28 breakout: is there such a thing?

[darthray]

Hello all,

I was thinking of getting a CRS504-4XQ-IN switch that has 4x 100G QSFP28 ports. I figured I would use a port to connect a second CRS504, 1 port connected to a server (ConnectX-4, most likely) and break out the last 2 ports into 8 SFP28 *cages* (the idea would be to distribute some 25G connections to various different rooms). Is there such a thing? I could find one.

Alternatively, I guess I could use a regular breakout but then I'd still need some sort of coupler to connect 2 "male" SFP28 connectors. Couldn't find one either.

How are folks using these 100G ports as 25G ports to be used "remotely" (i.e., not in the same rack as the switch)?

Thanks!

 

[ano]

I assume by "male sfp28" you mean.. normal LC connector, just use a coupler, or patch panel

 

[nexox]

The CRS510-8XS-2XQ is coming out soon and has the ports that you're looking for, it might be worth waiting (I already vaguely looked into options like this and decided to wait too.)

 

[NablaSquaredG]

Is there such a thing? I could find one.

Maybe try this obscure thing: QSFP+ Extender

 

[ano]

LC to LC Single Mode Fibre Optic Adapter, Quad - FS.com Europe

Buy LC to LC UPC fibre optic adapter from reliable fibre optics supplier - FS.COM, same-day shipping.

www.fs.com

 

[bitbckt]

You can use transceivers and optical breakouts or an AOC with 100G QSFP28 on one end and 4x duplex LC on the other.

Either way, what you want to do shouldn't be done over copper, which is why you aren't finding the product you are looking for.

 

[NablaSquaredG]

I assume by "male sfp28" you mean.. normal LC connector, just use a coupler, or patch panel

No.

I believe that @darthray wants to use 4 SFP28 transceivers in one 100G QSFP28 port of the CRS504-4XQ-IN

So either use the breakout / media converter I linked above or get a 100GBASE-SR4, breakout the MTP to 4x LC and use 4x 25GBase-SR Transceivers

 

[ano]

No.

I believe that @darthray wants to use 4 SFP28 transceivers in one 100G QSFP28 port of the CRS504-4XQ-IN

So either use the breakout / media converter I linked above or get a 100GBASE-SR4, breakout the MTP to 4x LC and use 4x 25GBase-SR Transceivers

uhm well that makes 0 sense, this is.. why we have the breakout cables!

 

[bitbckt]

get a 100GBASE-SR4, breakout the MTP to 4x LC and use 4x 25GBase-SR Transceivers

That one!

 

[NablaSquaredG]

uhm well that makes 0 sense, this is.. why we have the breakout cables!

Nope. You cannot plug in a transceiver into a breakout cable

 

[ano]

Nope. You cannot plug in a transceiver into a breakout cable

just plug the transceiver into network card, and breakout into that, TADA! ;D ;D ;D ;D

 

[darthray]

Maybe try this obscure thing: QSFP+ Extender

Thanks! This is very close to what I had in mind, although this one if QSFP+ to 4x SFP+ instead of QSFP28/SFP28. I would not need any "extender" functionality either so I'm hoping there's an inexpensive way of accomplishing that, hopefully.

 

[NablaSquaredG]

I would not need any "extender" functionality either so I'm hoping there's an inexpensive way of accomplishing that, hopefully.

100GBase-SR4 transceiver + MPO to LC breakout + Patch Panel + LC Duplex Multi Mode + 25GBase-SR4 transceivers

 

[darthray]

I assume by "male sfp28" you mean.. normal LC connector, just use a coupler, or patch panel

Sorry for my lack of knowledge of the terminology here.

Here's an example of what I was calling "male" SFP28:

Here's an example of the female SFP28 (these are present on switches and PCI cards):

 

[darthray]

The CRS510-8XS-2XQ is coming out soon and has the ports that you're looking for, it might be worth waiting (I already vaguely looked into options like this and decided to wait too.)

Thanks! I'm keeping an eye on that one as well, but it looks like it'll be more expensive. Well, if the breakout option ends up being costly, the CRS510 might make more sense.

 

[darthray]

You can use transceivers and optical breakouts or an AOC with 100G QSFP28 on one end and 4x duplex LC on the other.

Either way, what you want to do shouldn't be done over copper, which is why you aren't finding the product you are looking for.

Definitely not trying to do it over copper, but you make a good point: my searches may have limited me to copper breakouts.

 

[bitbckt]

Definitely not trying to do it over copper, but you make a good point: my searches may have limited me to copper breakouts.

That seems likely, yeah. I'd really suggest following @NablaSquaredG's path, but the other option I mentioned is 1m (3ft) Cisco Compatible 100G QSFP28 to 4 Duplex LC Breakout Active Optical Cable - FS.com. Depending on your tolerance for LC patching and how far you need the "legs" of the breakout to run, that might work for you as an all-in-one solution.

 

[darthray]

That seems likely, yeah. I'd really suggest following @NablaSquaredG's path, but the other option I mentioned is 1m (3ft) Cisco Compatible 100G QSFP28 to 4 Duplex LC Breakout Active Optical Cable - FS.com. Depending on your tolerance for LC patching and how far you need the "legs" of the breakout to run, that might work for you as an all-in-one solution.

I like this option! I haven't played with patching with LC connectors (my runs are mostly end-to-end with no patching), but if it works well at the rated speeds for runs < 30m, then this could work! Any suggestions for what to use on the patch panel?

 

[bitbckt]

You'll need at least 8 duplex LC connectors on the patch panel, so something generally like this: https://www.fs.com/products/41998.html

Note that the AOC is MMF, so you should not use something like this: https://www.fs.com/products/35488.html

You could also go the all-in-one panel route with a 1U panel like https://www.fs.com/products/35531.html More than you need, but doesn't require buying the high density panels that accept the modules.

 

[kpfleming]

Sorry for my lack of knowledge of the terminology here.

Here's an example of what I was calling "male" SFP28:

Here's an example of the female SFP28 (these are present on switches and PCI cards):

What you are calling a 'male SFP28' is an SFP28 transceiver; there many varieties of those. There also SFP28 DACs and AOCs which have 'male' ends.

What you are calling a 'female SFP28' is an SFP28 slot, which can accept a transceiver or one end of a DAC or AOC.

The commenters in this thread have shown you that there is no such thing as a QSFP28 to SFP28 *slot* breakout cable; breakout cables always have 'male' ends (whether those are transceivers or optical connectors).