At 03:09 PM 3/30/99 -0800, Jon Mansey wrote:
>Hi,
>
>Can anyone point me to some research or tables showing how BER affects
>TCP/IP thoughput?
>
>At the same time, does anyone have any real world experience of what is an
>acceptable BER to shoot for in designing end-end sat links for TCP/IP.
>
1E-8 or better. It really depends on the length of transfer. As soon as
you get an error, your window is going to half it size due to congestion
control. So for EXTREMELY long file transfers, you need near error free
links. For short file transfers, you'll never get past slow start. Also,
for hundreds of connections consisting of UDP and TCP, when one stream
reduces its rate, another will fill in the gap.
The following report has a graph showing TCP vs SPCS in an errored
environment. Remember. This is for a single stream. SCPS performs very
well here, but was optimized for a specific environment that does not
correspond to that of a commercial satellite.
http://www.scps.org/scps/assets/M22.pdf
Regards,
Will
*********************************************
William D. Ivancic
NASA Glenn Research Center
21000 Brookpark Rd. MS 54-8
Cleveland, Ohio 44135
USA
Phone: 1 216 433 3494
FAX: 1 216 433 8705
Email: [email protected]
[email protected]
http://ctd.grc.nasa.gov/5610/5610.html
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