QSPF 100Gb Intel PSM4 to 4x25Gb LC to different computers, switches, etc?

[McKajVah]

Hi.

I have a Mikrotik CRS504-4XQ-IN with one available spare 100Gb QSFP port that I want to use to go to some different eqipment.

Since one of my devices I want to go to is about 50m away, I cannot use a 100Gb to 4x25Gb Direct Attached breakout cable.

Is it possible to use for instance an Intel 100Gb QSFP PSM4 4xLC single mode transceiver module to go to different computers, switches, etc. putting some Optical 1310nm Single mode 25Gb SFP+ transceivers in the "other end"?

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I'm planning on using the last available port in the Mikrotik like this:
Mikrotik CRS504-4XQ-IN....................................... Other end

Intel QSFP PSM4 4x25Gb LC \---------------> 1: Optical LC SFP+ 25Gb - Computer 3 in same rack
..................................................\--------------> 2: Optical LC SFP+ 25Gb - Computer 4 in same rack
....................................................\------------> 3: Optical LC SFP+ 10Gb - Switch 50m away
......................................................\----------> 4: Spare

If it's possible to "split" the QSFP PSM4 transceiver like this for different equipment, or is it only meant to combine the 4 "channels" in same equipment again?
Can I also run at individual speeds or do they all need to match, meaning all four at 10Gb in my case?

Thanks.
Kaj

 

[ano]

psm4, should goto SFP28 and SFP+ LR modules in thery, that intel module might do some weird stuff though, so wouldnt bet on it working

the easy way is for you since its not going for a long distance

goto fs.com

get a standard SR4 module
get a Mpo/mpt to LC breakout om4 or om5

get 3x SR SFP28 modules... or for you, 2x SR SFP28, and 1x SR SFP+

you SHOULD be able to set 25x25x10. I have a 504 at the office, so I could try for breakouts onthat on different speeds

 

[TRACKER]

I use mpo/mtp SR4 (from fs.com) breakout cable (5m) in my homelab and i have 4 different machines connected on 25Gbps. Never tried different speeds (25 and 10) simultaneously, so cannot tell if this would work. Keep in mind breakout cables (in my case from fs) has really short wires on break out side (~40-50cm), that means machines you connect should be really close to each other.

 

[iGene]

I don't think it's possible to mix speeds in breakout. It's either 4x10G or 4x25G

 

[NablaSquaredG]

don't think it's possible to mix speeds in breakout. It's either 4x10G or 4x25G

With DACs it's usually possible, but I doubt that it'll work with transceivers

 

[klui]

It may work with other ASICs but won't work on a Tomahawk-based switch, even through you can set each breakout port to a different speed. They will only link at 10G or 25G at any given time, not both concurrently. I only tried using passive DACs.

 

[McKajVah]

you SHOULD be able to set 25x25x10. I have a 504 at the office, so I could try for breakouts onthat on different speeds

Yes, it would be great if you can test without disturbing any of the "operations" ongoing at your work... Thanks.

 

[jabuzzard]

I use mpo/mtp SR4 (from fs.com) breakout cable (5m) in my homelab and i have 4 different machines connected on 25Gbps. Never tried different speeds (25 and 10) simultaneously, so cannot tell if this would work. Keep in mind breakout cables (in my case from fs) has really short wires on break out side (~40-50cm), that means machines you connect should be really close to each other.

You can get fs.com to do custom breakout cables if you want with the breakout where you want. However, given how pricey breakout cables are I would suggest getting a short 1m breakout and using couplers or a patch panel to go your end devices. Then you are unlikely to damage your expensive breakout cable. Also that way you can have different lengths to different end devices no problem.

 

[LodeRunner]

Yeah, a short fanout cable to LC/LC keystones (if you have a panel) or couplers is the simplest way to do the cabling.

 

[NPS]

Can I also run at individual speeds or do they all need to match, meaning all four at 10Gb in my case?

Got a cheap CRS504 and tried this with a passive DAC. It works very well at 10/25/25/25 for a few days now. It's a bit obfuscated in their wiki. The parameters for speed are a little different then in the Mikrotik wiki aswell. Just use auto completion to find the correct values. (they have options for DACs and different transceivers now but not a general speed setting anymore). Interestingly there are options to set the port to 2x50 despite the wiki saying this is not possible. Unfortunately I have no cable to try if it works.

I have no idea if combining different speeds in a single port works with optics! Maybe this is even dependent on the transceiver? Would the transceiver need to support it?