Problems with sr driver and Wanic 400

[John Levine]

I'm trying to put together a freebsd 6.1 T1 router with an old PC and
a Wanic 400 card I bought on ebay.  I'm using the sr driver netgraph,
mpd, and pf with altq, since I want to do priority routing for some
voip phones.

It all works fine until the t1 gets busy, e.g., if I do a wget on
the router, and which point it starts complaining about TX overruns
and the traffic on the wanic stops.  Any suggestions?

The PC is pretty slow, and one thought is that I also have an old
SDL RISCom/N2 ISA card which is slower than the wanic.  Is that
likely to work more reliably?  Speed isn't much of an issue on a
single t1 and yes, the PC is old enough that it has ISA slots.

R's,
John