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RE: Why not have both?


The 9.584640 Gbps rate comes from the payload rate of a SDH VC-4-64c
channel which has 1 column of Path and 63 columns of fixed overhead. The
OC-192c rate is slightly larger at 9.620928 since it does not use the fixed

The calculation for these numbers in available in my Montreal presentation.
The data bytes available in a SDH VC-4-64c frame are 16,640 bytes/row by 9
rows. We agree on the Baud rate at 9.953280 Gbps and the SPE rate at
9.621504 Gbps.


At 04:50 PM 9/15/99 -0400, Edward Chang wrote:
>Paul Bottorff:
>Would you mind answer Dae Young Kim's question?  The similar question was
>asked before, and I believe, you handled that question.
>Ed Chang
>NetWorth Technologies, Inc.
>-----Original Message-----
>From: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
>[mailto:owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx]On Behalf Of Dae Young KIM
>Sent: Wednesday, September 15, 1999 5:27 AM
>To: Edward Chang
>Cc: rabynum@xxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
>Subject: Re: Why not have both?
>One question on the number.
>According to my calculation, with OC192
>    - The Gross rate is        9.95328  Gbps
>    - The SPE rate is          9.621504 Gbps
>    - The user data rate is    9.510912 Gbps
>Where does the number 9.548 come from? We've been talking about the pure
>payload, so I'd pick 9.510 Gpbs Ethernet NRZ rate.
>I should be mistaken somewhere. Would you please correct me?
>Edward Chang wrote:
>> Roy:
>> Thanks for proposing a simple WAN/PHY specification.  We can move on from
>> here to generate a complete specification for HSSG.
>> I like the fact that your WAN/PHY is based on OC-192C signaling standard,
>> which is widely implemented in the marketplace - Light SONET.
>> Your proposal, surely, is a simple, bare-bone overhead, which I think will
>> do the job.
>> Nevertheless, if there is any other proposal, we should also discuss it.
>> Also, it is the time to start deal with those issues: 9.548...Gbps NRZ
>> scramble data, data rate conversion scheme (10.000/9.548.Gbps), framing,
>> recovered clock characteristics (should meet SONET jitter-transfer,
>> jitter-tolerance, and jitter-generation? Probably not), clock frequency
>> tolerance (100 ppm?), data jtter characteristics, BER, fault reporting,
>> SERDES, target distance (40 km max?), media......etc.
>Dae Young KIM
Paul A. Bottorff, Director Switching Architecture
Enterprise Solutions Technology Center
Nortel Networks, Inc.
4401 Great America Parkway
Santa Clara, CA 95052-8185
Tel: 408 495 3365 Fax: 408 495 1299 ESN: 265 3365
email: pbottorf@xxxxxxxxxxxxxxxxxx