How to connect 200GbE QSFP56 DPU to 100GbE (QSFP28) based Network

[L.P.]

Hi everyone,

We recently bought an NVIDIA ARM Devkit with the BlueField 2 DPU, and I am trying to connect it into the rest of our network (once it arrives). The rest of our network is based on QSFP28 100GbE with a 32 * 100GbE switch at its core.

What would the best way be to connect the DPUs into our network? Would the DPUs be able to accept a 100GbE QSFP28 to QSFP28 direct-attach copper cable to connect at 100GbE speed, or would one need a breakout-cable?

What would you suggest?

Thank you for your time - L

 

[Rand__]

I have no clue, but from a historical point of view I would expect it to work with the 100G cable.

Asking google ... says
Network Interfaces
> Ethernet - Dual ports of 10/25/50/100Gb/s,
or a single port of 200Gb/s
> InfiniBand - Dual ports of EDR / HDR100,
or single port of HDR

https://www.nvidia.com/content/dam/en-zz/Solutions/Data-Center/documents/datasheet-nvidia-bluefield-2-dpu.pdf

so quite likely

 

[L.P.]

They are single port 200Gb/s QSFP56 cards

 

[necr]

QSFP56 is backwards compatible to QSFP28 - tested on my ConnectX-6. Just plug in your 100G cable. Hell, you can even plug in 200G cable if it supports lower speeds - modern AOC and DACs actually support this. Don't connect QSFP-DD tho.

 

[L.P.]

Ah, that makes life very easy! Thank you so much! I was not aware of them being backward-compatible, and hence racking my brain to connect the server into the rest of the network..