nanog mailing list archives
Re: MCI [ATM overhead]
From: salo () msc edu (Tim Salo)
Date: Wed, 20 Mar 1996 22:56:32 -0600 (CST)
From: Wolfgang Henke <wolfgang () whnet com> Subject: Re: MCI [ATM overhead] To: johnc () msc edu Date: Wed, 20 Mar 1996 08:38:08 -0800 (PST) Cc: nanog () merit edu a [...] 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 [...]
I think your 122 Mbps "ATM" number could be a bit confusing, even knowing the assumptions you described in earlier mail. (Also, more bandwidth seems to be available to "TCP/IP" than appears to be available from ATM...) If it helps, the following numbers are from John Cavanaugh's paper: Line Rate 155.520 Mbps Available to ATM 149.760 (SONET payload) Available to AAL 135.632 (ATM payload) John then computes the overhead for three MTUs, and yields rates available to IP and TCP: MTU 576 9180 65527 Available to IP 125.198 135.102 135.547 Available to TCP 116.504 134.513 135.464 These are the maximum available rates, namely they assume MTU-sized packets. The reader can apply their favorite packet size distributions to these numbers. Having said all that, I am not sure where that leaves us. One could theoretically remove the SONET overhead, but then one looses the ability to manage the SONET link. One could remove the ATM overhead, but then one has a point-to-point link, rather than a link over which data from many sources can be multiplexed. -tjs
Current thread:
- Re: MCI [ATM overhead], (continued)
- Re: MCI [ATM overhead] Gary R Wright (Mar 19)
- Re: MCI [ATM overhead] Jim Forster (Mar 19)
- Re: MCI [ATM overhead] Paul Ferguson (Mar 19)
- Re: MCI [ATM overhead] Wolfgang Henke (Mar 19)
- Re: MCI [ATM overhead] John Cavanaugh (Mar 20)
- Re: MCI [ATM overhead] Wolfgang Henke (Mar 20)
- Re: MCI [ATM overhead] Paul Ferguson (Mar 20)
- Re: MCI [ATM overhead] Mark A. Luker (CISE/NCRI) (Mar 22)
- Re: MCI [ATM overhead] Vadim Antonov (Mar 20)
- Re: MCI [ATM overhead] Shikhar Bajaj (Mar 20)
- Re: MCI [ATM overhead] Tim Salo (Mar 20)
- Re: MCI [ATM overhead] Jon Zeeff (Mar 21)
- Re: MCI [ATM overhead] William Allen Simpson (Mar 21)
- Re: MCI [ATM overhead] Shikhar Bajaj (Mar 21)
- Re: MCI [ATM overhead] Shikhar Bajaj (Mar 21)
- Re: MCI [ATM overhead] Tim Salo (Mar 21)
- Re: MCI [ATM overhead] Jeff Ogden (Mar 21)
- Re: MCI [ATM overhead] Wolfgang Henke (Mar 21)
- Re: MCI [ATM overhead] Vadim Antonov (Mar 21)
- Re: MCI [ATM overhead] Kent W. England (Mar 22)
- Re: MCI [ATM overhead] Tim Salo (Mar 25)
(Thread continues...)