Thomas and Sylvain,
I did a quick test and found that with the ordinary FTP client on
Windows 98 and FTP server on Solaris 2.6, the throughput for a large
file (18228147 bytes) FTPed across a GEO based satellite (Intelsat)
using COMSAT's Linkway 2000 IP product (that you referred to) was
741.84 kbps (on average) with Committed Allocation and 692.64
kbps (on average) with Bandwidth on Demand (with initial 64 kbps
seed allocation). The reason that there is a comparatively low
throughput with BoD is because of the chicken and egg problem faced
with running TCP over a BoD, large delay system. The only difference
between your setup and mine was that I used native IP from Linkway
and you used IP over Frame Relay but this is not relevant to the
case, I believe.
I configured only two parameters to see such a change in throughput:
the 'tcp_xmit_hiwat' param in Solaris and 'DefaultRcvWindow' in
Windows 98. I believe (not sure!) that support for Large Windows is
inherent to these two OSs by default. Both params were set to 64K.
Compare these values with a DefaultRcvWindow size of 8K which would
give a throughput of approx 80 kbps.
Best regards,
Nalin Mehta
Linkway 2000 IP development team,
Comsat Labs, Clarksburg, MD 20871.
> > -----Original Message-----
> > Hi from France.
> >
> > we are testing the Comsat VSAT solution (linkway 2000) but we have a
> > limitation about the bandwidth on a TFTP, FTP and RTSP transfer.
> >
> > for instance, on an FTP or TFTP transfer, we are up to 80 kbps on each to
> > session. That is to say, if I open 4 FTP sessions, I am able to transfer 4
> > different files at each 80 kbps.
> > The purpose is to be able for me to transfer in one session up to 2 Mbps (my
> > bandwidth on the sattelite)
> >
> > I am using Windows 98 on each point of the connection.
> >
> > Is anybody can help me ?
> >
> > Thomas Wiard
> > [email protected]
> > phone : +33 1 42 30 18 66
> > mobile : +33 6 14 98 69 63
This archive was generated by hypermail 2b29 : Fri Feb 25 2000 - 15:57:41 EST