I'm using netbsd as a gateway/workstation.  P133/32 with scsi disks.
I'm having an issue which I've seen off and on for a very long time
in which the network just clogs up and ceases to move.  I run ppp over
a v.34 modem attached to a 16550.  Lockups appear to occur with 
heavy network use, but not always.  This last one happened while a
client was running cu-seeme, so heavy udp use.

netstat -m
326 mbufs in use:
        292 mbufs allocated to data
        34 mbufs allocated to packet headers
153/194 mapped pages in use
428 Kbytes allocated to network (80% in use)
0 requests for memory denied
0 requests for memory delayed
0 calls to protocol drain routines

mbufs allocated go up slowly as crap is added to the outgoing queue.

pppstats reveals nothing going across the line.

Powercycling the modem causes this:
      IN   PACK VJCOMP  VJUNC  VJERR  |      OUT   PACK VJCOMP  VJUNC NON-VJ
       1      0      0      0      0  |      455      1      0      0      1

and a drop in the backed up mbufs

netstat -m
155 mbufs in use:
        155 mbufs allocated to data
132/194 mapped pages in use
407 Kbytes allocated to network (69% in use)
0 requests for memory denied
0 requests for memory delayed
0 calls to protocol drain routines

Once the modem redials and connects, all appears well again.  Comments?

-j