When I bring up a system built from July 17 sup sources, pppd does
not appear to finish the job of bringing up the ppp interface.
It successfully dials the phone, PPP LCP comes up, the ip-up script
gets run, and "ifconfig ppp0" claims the interface is up and running,
but pinging the address of the other host of the PPP link results in
"net_send: net is down".  netstat -r says the default route is through
the remote host via ppp0, and there's a host route for the remote host
through the address on my end of the link via ppp0.

Note that everything works fine using the same scripts with sources
from very early July (just before the new PPP was installed).  Is
there a really obvious source of trouble?  If not, what other
information should I provide, or what should I look for?