DAC cables for MS120 switches - MA-CBL-TA-1M and MA-CBL-TA-3M

[Baka]

I know they are 10GB transceivers going in 1 Gb ports..  but should they work?    They are still cheaper than getting 1GB  SFPs...

[cmr]

I think they are 10Gb only, but to be honest haven't tried one!

[Brash]

You'd have to try it to confirm but relatively sure that it won't work in a 1G port 

[GreenMan]

I take it you don't have any spare built-in Gig RJ45 ports?   You don't have to use the SFP slots for uplinks

[Baka]

there are ports available on the RJ45 side, but really wanted the uplinks to be done on the SFP side. I know it's not a massive difference, but it is more reliable and less latency, DAC  would've been nice to have to not use any of the RJ45 ports for that either..   

[Baka · Accepted solution]

I got the answer from someone who had a cable to try it out and they won't work, they are coded as 10GB and won't drop down to 1 GB as a transceiver would.  so in this case the RJ45 uplink will have to do.    Cheers to all that have replied and will  close this down and accepting my solution 🙂  

[GreenMan]

This is generally the case for anything SFP / SFP+ based - they are fixed at a single rate.

[GIdenJoe]

There are no 1 GB DAC cables.  The lowest speed any DAC cable exist is at 10 Gbps.  Since the MS120 series only has SFP it does not support the 10 Gbps needed for DAC cables.

Each switch series also shows the compatible accessories in the datasheet.

[benny]

Hi Baka, 

I understand there is a official datasheet however, I have had mixed results in the past and have had the MA-CBLs come up at 1Gbps line rate. 

Image attached, I have a MS210-48LP uplinked via its SFP port using MA-CBL-TA-1M into a MS410-16 SFP port. The interface is up and the speed negotiated at 1Gbps

[benny]

Further test to confirm MA-CBL can be used for 1G / 10G mixed. 

MS225-48FP SFP+ port >>> MA-CBL-3M >>> MS220-8P SFP port came up once I changed the link negotiation to 1Gbps 

[GIdenJoe]

That's weird and shouldn't officially work.