[pptp-server] pptpd 1.0.0 / Win98 performance problem

[D.J. Heap]

> All great so far, then I actually use the connection from the client
> side (hit an internal website). Before the website is loaded I see:
>
> 64 bytes from x.x.x.x: icmp_seq=10 ttl=128 time=42.2 ms
> 64 bytes from x.x.x.x: icmp_seq=11 ttl=128 time=60.6 ms
> 64 bytes from x.x.x.x: icmp_seq=13 ttl=128 time=2690.4 ms
> 64 bytes from x.x.x.x: icmp_seq=14 ttl=128 time=4331.3 ms
> 64 bytes from x.x.x.x: icmp_seq=18 ttl=128 time=495.5 ms
> 64 bytes from x.x.x.x: icmp_seq=19 ttl=128 time=6763.5 ms
> 64 bytes from x.x.x.x: icmp_seq=20 ttl=128 time=6072.7 ms
> 64 bytes from x.x.x.x: icmp_seq=21 ttl=128 time=7075.6 ms
> 64 bytes from x.x.x.x: icmp_seq=22 ttl=128 time=6081.9 ms
> 64 bytes from x.x.x.x: icmp_seq=23 ttl=128 time=6036.2 ms
> 64 bytes from x.x.x.x: icmp_seq=24 ttl=128 time=5977.3 ms
> 64 bytes from x.x.x.x: icmp_seq=25 ttl=128 time=10531.3 ms
>
> ... and then the connection will finally break down entirely and no
> data will be transferred. There is not a connection problem between me
> and the server at all. At the time of testing I was getting <20ms and
> no packet loss.


I am experiencing very similar difficulties with Win98.  I have not had the
opportunity to try Win2k or NT yet, but I will do that when I have some time
to install them on a test machine.  I have upgraded to 1.0.0 and still have
the same troubles, btw.

I cannot even keep a steady ping going.  It seems somewhat sporadic, ping
will work fine for a few seconds in both directions (from client to server,
server to client) then it will stop working for a few seconds...then a few
seconds later it will ping ok again for a while.  Attempting any sort of
large data transfer at all is utterly unsuccessful.

I have noticed when I turn on debugging, I see many many 'GRE: Discarding
out of order packet' messages and the occasional 'GRE: Discarding duplicate
packet' messages...the out of order packet messages far far outnumber the
duplicate packet messages, however.

Any help or information would be appreciated, and, of course I am very
willing to help in any debugging I can.  I have not tried altering the
PCKT_RECV_WINDOW_SIZE or any other code, yet, but I will if that might help?

Thanks,

DJ