[pptp-server] pptpd 0.9.16 / Win98 performance problem

[Chris Hyde]

Tried everything ... just kept incrementing it by 1 to see if the 
behaviour changed. It exhibited the same behaviour with 1,2,4,8 ...
though larger values would increase performance for a while until
it would flake out.

Chris

On Mon, Sep 13, 1999 at 10:35:09AM -0400, Philip Van Baren wrote:
> Chris,
> 
> When you tweaked the PCKT_RECV_WINDOW_SIZE, what values did you try?  With
> my setup, using a value of 1 gives poor performance, 2 through 8 give OK
> performance, and above 8 (or matching the other side's value, like is done
> in 0.9.16) results in lots of dropped packets.
> 
> i.e. try making the following change in ctrlpacket.c to see if this works
> better:
> 
> /* lets match their window size for now... was htons(PCKT_RECV_WINDOW_SIZE)
>  */
> out_call_rply.pckt_recv_size = htons(4); /* out_call_rqst->pckt_recv_size;
> */
> 
> Philip Van Baren
> 
> > -----Original Message-----
> > From: pptp-server-admin at lists.schulte.org
> > [mailto:pptp-server-admin at lists.schulte.org]On Behalf Of Chris Hyde
> > Sent: Friday, September 10, 1999 9:08 PM
> > To: pptp-server at lists.schulte.org
> > Subject: [pptp-server] pptpd 0.9.16 / Win98 performance problem
> >
> >
> > Hi there,
> >
> > Has anything been resolved with the pptpd / Windows 98 performance
> > issue? I've just read through the archives and there seems to be
> > no answer.
> >
> > My problem:
> >
> > RedHat 6.0 2.2.10 kernel pptpd 0.9.16 Server on a 3Mb/s fibre
> > Win98 client on a cable modem connection.
> >
> > Usual ping is ~25ms.
> >
> > Connect via VPN and start a ping on the server back to my client:
> >
> > PING x.x.x.x (x.x.x.x): 56 data bytes
> > 64 bytes from x.x.x.x: icmp_seq=0 ttl=128 time=33.3 ms
> > 64 bytes from x.x.x.x: icmp_seq=2 ttl=128 time=32.5 ms
> > 64 bytes from x.x.x.x: icmp_seq=3 ttl=128 time=32.9 ms
> > 64 bytes from x.x.x.x: icmp_seq=4 ttl=128 time=31.7 ms
> > 64 bytes from x.x.x.x: icmp_seq=5 ttl=128 time=35.8 ms
> > 64 bytes from x.x.x.x: icmp_seq=6 ttl=128 time=35.6 ms
> >
> > 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 tried tweaking the PCKT_RECV_WINDOW_SIZE and this improved performance
> > but I would eventually get the same out-of-sync like behaviour where
> > the pings would go through the roof and stay there.
> >
> > Higher WINDOW_SIZE's would just put this off for a few more pages ...
> >
> > Anyone have any answers for this one?
> >
> >
> > --
> > **********************************************************************
> > Chris Hyde
> > The Electric Mail Company
> >
> > Voice : (604) 482-1111                  Info  :   www.electricmail.com
> > Fax   : (604) 482-1110                  Email : chris at electricmail.com
> >
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> >          baggets or bagels. No croissants, no crumpets, no pancakes,
> >          no potato cakes, and no hot cross buns. And definitely no
> >          smegging flapjacks!
> > Toaster: Ah! So you're a waffle man!
> >
> > ***********************************************************************
> >
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-- 
**********************************************************************
Chris Hyde
The Electric Mail Company

Voice : (604) 482-1111                  Info  :   www.electricmail.com
Fax   : (604) 482-1110                  Email : chris at electricmail.com

One tequila, two tequila, three tequila, floor.

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