You could possibly try the following command. I'm not sure if it's exactly what you're looking for, but it will give you the current line rate in kbps. Changing, of course, the interface name to match your configuration.
show interfaces at-1/0/0 extensive | match Bit
Also, under the "extensive" interface command it will give you the traffic statistics for input/output but it's in bps, so some maths may be required.
Not sure if any of that helps, but it's the best I could find.
Hi, thanks Brandon.
It was actually the OID/MIB I was looking for. I have actually managed to find this now, it is 126.96.36.199.188.8.131.52.184.108.40.206.2 and 220.127.116.11.18.104.22.168.22.214.171.124.2.
Juniper and Cisco seem to use opposite OIDs for upload and download though?