Out-of-band data problem

[Jon Oelnes]

Three years ago we finished an implementation of the X.25 Packet
Layer Protocol in the kernel of 4.3BSD UNIX on a VAX 11/750. This
protocol supports out-of-band data (interrupt packets). According
to the manual receipt of out-of-band data is signalled by a SIGURG
to the receiving process, and the data may be read with a recv call
with the OOB-flag set.
On the VAX this never worked because the SIGURG signal never appeared.
I traced execution to the socket layer (sohasoutofband), and it seemed
like the process id. of the receiver wasn't found.
Since this was an experimental implementation only, and we ran out of
fundings, we never really tried to solve the problem. Recently, however,
we ported the code to run on a SUN (SUN OS 4.0.1), and the out-of-band
stuff immediately worked !!!
Is there some well-known bug in the 4.3 BSD VAX kernel that causes
this problem in the original case, and if yes, is there a fix ??
We would like to get this right on the VAX as well.

Please mail answers. My "official" mail address is:
   olnes%nr.uninett at tor.nta.no
but the gateway to the UNINETT X.400 mail is not reliable for the time
being, so better use:
   jon at ifi.uio.no

Thanks in advance.

Jon \lnes, Norwegian Computing Center
           Po.box. 114 Blindern
           N-0314 Oslo 3
           Norway
(No, it's not a backslash in my name, I'm Norwegian)