We use them on MX304 at 10g, primarily to get DWDM SFP+ to work. MTU is fine, it's 9k as a part of LACP on a recent deployment. The adapter simply passes through lane :0 to the port when configured as QSFP+. If you insert the adapter and no optic, the device is unaware of its existence - you only see the SFP+ info.
We haven't tested in prod on 1g but i think we did in the lab. can probably toss something in there if you're really curious. I think the juniper supported optic page lists QSA adapter support or not. I thought it was generally supported with Junos 20+ nowadays. me@mx304> show chassis pic fpc-slot 0 pic-slot 1 | match 14 14 10GBASE ZR SM FLEXOPTIX P.1596.80 1550 nm 0.0 1550nm SFF-8472 ver 10.2 me@mx304> show interfaces terse | match xe-0/0/14 xe-0/0/14:0 up up xe-0/0/14:0.0 up up aenet --> ae5.0 me@mx304> show interfaces ae5 | match mtu | match roto Protocol inet, MTU: 9000 Protocol inet6, MTU: 9000 Protocol mpls, MTU: 9166, Maximum labels: 3 Protocol multiservice, MTU: Unlimited Cheers Chris On Fri, Nov 3, 2023 at 8:01 AM Ola Thoresen via juniper-nsp < juniper-nsp@puck.nether.net> wrote: > Hi all, > > I am currently investigating the use of 1G and 10G optics on the MX304. > > This requires a QSA adapter - > > https://mellanox.my.site.com/mellanoxcommunity/s/article/all-about-qsa-adapter > - That is fine. > > But then I hear people telling me that there is a known limitation when > using these adapters that you can not have a higher MTU than ~2000 Bytes > at _least_ when using 1G SFPs, but possibly also with 10G. However, I > can not find _any_ information about that anywhere. Not from Juniper, > not from Mellanox (Nvidia), nor from any user guides or datasheets I > have found for the adapter from various vendors, and not from any mail > archives, forums or anywhere else my Google-foo is taking me. > > Those who raised the issue are quite insistent that it is real, but they > don't have any links or documents backing them up. Is it just FUD? > > * Has anyone ever used these adapters? > > * In a Juniper device (they are supported on different platforms)? > > * With 1G or 10G SFPs? > > * With (or without) adjusting the MTU? > > > /Ola (T) > _______________________________________________ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp > _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp