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Don,
Your understanding of the SONET deserializer/section framer is correct. It does
require bit slipping to frame & ensure the demux'd byte alignment corresponds
with SONET bytes. If the path payload is byte oriented, then no further alignment is
required, as with our <length><type><HEC> proposal. If the path payload is not byte
oriented, then a subsequent bit slipping delineation is required, as with 64B/66B in
SONET. Keep in mind there is the SONET section layer framer & then the SONET
path layer payload delineation.
...Dave
David W. Martin
Nortel Networks
+1 613 765-2901
+1 613 763-2388 (fax)
dwmartin@xxxxxxxxxxxxxxxxxx
========================
-----Original Message-----
From: Don Alderrou [SMTP:dona@xxxxxxxxxxx]
Sent: Thursday, April 13, 2000 9:11 PM
To: stds-802-3-hssg@xxxxxxxx
Subject: RE: Interface reality check
At 11:07 AM 4/13/00, David Martin wrote:
>Bharadwaj,
>
>The issue with 66-bit alignment vs 8-bit alignment arises at the receive end.
>The SONET section framer provides a byte-aligned output. If the payload is
>byte aligned then the payload delineation mechanism can hunt directly. If the
>payload is 66-bit aligned, then the delineation mechanism must hunt on a bit
>by bit basis. Bit-slipping vs byte-slipping involves more circuitry.
>
>...Dave
>
>David W. Martin
>Nortel Networks
>+1 613 765-2901
>+1 613 763-2388 (fax)
><mailto:dwmartin@xxxxxxxxxxxxxxxxxx>dwmartin@xxxxxxxxxxxxxxxxxx
Dave,
Now you have me confused. I was under the impression that any
de-serialization process which converts a serial bit stream into
a parallel bit stream requires a single bit slip to gain alignment
to the delineators. Here you are saying the SONET framer does
not require a single bit slip. Can you please explain how the
SONET serial bit stream is converted to a parallel bit stream
without the single bit slips?
Thank you,
--Don
--------------------------------------------------------------
Don Alderrou mailto:dona@xxxxxxxxxxx
nSerial Corporation Tel: 408-845-6105
2500-5 Augustine Dr. Fax: 408-845-6114
Santa Clara, CA 95054 http://www.nserial.com/