johnc@msc.edu (John Cavanaugh) writes:
You can find a paper that addresses this question at
http://www.msci.magic.net/docs/magic/overhead.ps or fte:ftp.magic.net/pub/magic/overhead.ps
It covers OC-3c, OC-12c, 100 and 140 Mbps TAXI, and DS3 framing, and gives the effective bandwidth at each layer.
Thank you for the reference. I will certainly check it out. Here is a little table which I hope will help ISPs planning to upgrade bandwidth: SONET (Synchronous Optical Network) speeds given in Mbps nominal w/o Sonet ATM TCP/IP overhead OC-3 STS-3c 155.520 149 122 137 future net backbone OC-12 STS-12c 622.080 599 488 549 OC-48 STS-48c 2488.32 2396 1953 2197 current telco backbone OC-192 STS-192c 9953.28 9585 7813 8788 on single mode fiber or multi mode fiber or CATV 75 ohm coax (the lower speeds) Additions and corrections are welcome. Wed Mar 20 07:56:41 PST 1996 http://www.whnet.com/wolfgang/sonet.html
John Cavanaugh EMail: johnc@msc.edu Minnesota Supercomputer Center, Inc. johnc@cray.com 1200 Washington Ave. S Phone: +1 612 337-3556 Minneapolis, MN 55415 FAX: +1 612 337-3400
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