How can I further diagnose this problem?
Is 'buffer space' apart from mbufs?  I should have plenty of mbufs.
How can i see what has consumed this 'buffer space'?  How can i clear
it other than dropping the ppp line?

-j

>PING abattoir.com (204.17.233.67): 56 data bytes
>ping: sendto failed: No buffer space available
>ping: sendto failed: No buffer space available
>^C
>----abattoir.com PING Statistics----
>2 packets transmitted, 0 packets received, 100% packet loss
>gabriella% netstat -m
>100 mbufs in use:
>        81 mbufs allocated to data
>        6 mbufs allocated to packet headers
>        13 mbufs allocated to socket names and addresses
>22/112 mapped pages in use
>236 Kbytes allocated to network (23% in use)
>0 requests for memory denied
>0 requests for memory delayed
>0 calls to protocol drain routines
>gabriella% !pi
>ping limbo
>PING abattoir.com (204.17.233.67): 56 data bytes
>ping: sendto failed: No buffer space available