Hi Jason - Answers, and more. I hope this is useful and helps clarify the
options. - MLD

1) The N32x QSFP+ port/link/interface should work with UHD 3.15 via the XQ
FPGA image. I haven't tried that in a while, but it did work for me once
upon a time.

2) When using the WX FPGA image on any N3xy, you get just SFP+ port 1 for
data, which is just a single 10 Gb link -- not the QSFP+ port (which is on
the N32x only, by the way). If you use the XQ FPGA image with the N32x then
you get 1x or 2x 10 Gb links via the QSFP+ port: lanes 0 and 1 (or 1 and 2
if you count lanes as 1's-based). In theory you could use 2x SFP+ 10 Gb
links on a host NIC and aggregate them via fiber into a QSFP+ adapter
attached to the USRP; I've never tried this directly, but I can say that
taking QSFP+ off a host NIC and switching lanes works fine using the
appropriate adapters and fiber cables and connectors. Just make sure that
lanes 0 &/or 1 on the USRP side match up correctly with the other side
coming in (whatever lane[s] you choose to use, so long as it/they are valid
on the NIC).

3) When using the WX FPGA image with an N3xy, "ifconfig" will report back
just "sfp1" as the 10 Gb data link that is connected to SFP+ port 1 on the
USRP; not the QSFP+ port (which is, again, on just the N32x); this single
link is set that up as you would any data link on a USRP and host. If you
use the XQ FPGA image with an N32x, "ifconfig" will report back "sfp0" and
"sfp1" as the 2 10 Gb data links, and you set those up just as you would if
you were using the XG FPGA image. The FPGA maps between the data link (SFP+
or QSFP+) and the OS, so that the OS "sees" 1 or 2 10 Gb links; or that's
how I understand this to work ... the end result is the same regardless of
where the mapping happens :)


On Fri, Jun 4, 2021 at 2:26 PM Jason Matusiak <[email protected]>
wrote:

> I have been away from USRPs for a while but am back to using some N3x0
> units and am having some issues.
>
> 1 - Does QSFP work with UHD 3.15?  We'd prefer not to go up to v4 yet due
> to some issues we've seen in testing it, but I am not sure how well
> supported QSFP is on 3.15.
>
> 2 - When using the QSFP with White Rabbit (WX image), is it correct to say
> that the QSFP link is really x2 10Gb links, not a single 20Gb?  Meaning
> that we would need a 40Gb QSFP that can handle 4 10G outputs, correct?
>
> 3 - Lastly, I cannot find any documentation on setting up the QSFP.  I've
> downloaded a new WX image over Mender, but I don't see where/how to
> configure the QSFP.  Is there an article or writeup anywhere that walks
> through the steps?
>
> Thank you
> _______________________________________________
> USRP-users mailing list -- [email protected]
> To unsubscribe send an email to [email protected]
>
_______________________________________________
USRP-users mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to