RE: Question on XSBI
Hi, Gary,
In the transmit case, the WIS will send data on the XSBI with the proper A1/A2 alignment such that the LW-4 PMA will not need to do framing. This is actually automatic (you have to go to some trouble to NOT do this!), but Clause 50 specifies this anyway for completeness. In the receive case, the the XSBI receive path into the WIS does not require any A1/A2 alignment; however, the LW-4 PMA - but not the serial PMA - will have to do basic A1/A2 framing so that it can align the incoming streams.
Best regards,
- Tom Alexander
-----Original Message-----
From: Gary Nicholl [mailto:gnicholl@cisco.com]
Sent: Thursday, February 22, 2001 12:52 PM
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 .....