RE: Question on XSBI
Gary,
You are correct. Clause 51 does not specify an alignment, nor was it
intended to do so. Alignment has to be handled by the PCS/WIS layers.
Further more alignment doesn't really make sense in the LAN case (66 bits on
a 16-bit interface).
As I have understood the discussions, the WAN WDM PMA has to look for A1s
and A2s and perform deskew and alignment. Lately I have only followed the
serial clauses in detail, so I don't know if this is implemented in the
draft.
Kind regards,
Henning
-----Original Message-----
From: Gary Nicholl [mailto:gnicholl@cisco.com]
Sent: 22. februar 2001 21:52
To: stds-802-3-hssg@ieee.org
Subject: Question on XSBI
I have been reading through clause 53 and it triggered a question on XSBI.
Are the 16 data bits of the XSBI interface in any way aligned with the byte
boundaries of the SONET frame ? I don't believe that any alignment is
specified in the OIF SFI-4 spec. If this is the case does it mean that the
LW4-PMA has the ability to locate the SONET A1/A2 frame boundary on any one
of 16 possible bit alignments within the XSBI interface ?
Gary .....