nanog mailing list archives

Re: MCI [ATM overhead]


From: Paul Ferguson <pferguso () cisco com>
Date: Wed, 20 Mar 1996 15:08:18 -0500

At 08:38 AM 3/20/96 -0800, Wolfgang Henke wrote:


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)


And here's one that [fills in the gaps] shows the relationship between STS
and SDH:

SONET/SDH Heirarchies

SONET                Bit Rate           SDH

STS-1/OC-1           51.84 Mb           -
STS-3/OC-3           155.52 Mb          STM-1
STS-12/OC-12         622.08 Mb          STM-4
STS-24/OC-24         1244.15 Mb         -
STS-48/OC-48         2488.32 Mb         STM-16
STS-192/OC-192       9953.28 Mb         STM-64

- paul



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