Hello,

Read your mail and immediately thought of something... I had the same kind
of a problem a long time ago when using PPP on a 14.4K modem. I understood
that you also use PPP, so I think the neither modem nor NetBSD is to blame -
pppd is.

Check your pppd options for asyncmap. If you have not defined an alternative
asyncmap in your options pppd will escape EVERY control characters (32 of
them?) and send them as 2-byte sequences. 32/256 = 1/8 => in the worst case
scenario 12,5 % of transferred octets would expand to two bytes.

To further tweak performance you could turn rfc1323 extensions (or smthing)
off with sysctl, although this does not have any big effect.

  Arto Huusko