Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [HSSG] fault signalling


Distraction appreciated.

And we're in tune re c57 etc.


David W. Martin
Nortel Networks
+1 613 763 3874 (esn 393)

-----Original Message-----
From: Hugh Barrass [mailto:hbarrass@CISCO.COM] 
Sent: Tuesday, September 25, 2007 2:39 PM
Subject: Re: [HSSG] fault signalling

David & others,

I'm sorry to distract from the hotel charge conversations :-)

Using the current architecture of OAM in Clause 57, there is no problem 
dealing with the multiple lanes - regardless of the physical layer 
solution. The OAM structure allows anything defined in the MIB structure

to be transported as information in the OAM PDUs. It is really just a 
matter of definition. If the committee decides to include manageability 
support when it defines the PCS and lane structure then the OAM will be 
able to transport it. There are examples of this in Clause 61 (EFM 
copper PCS) and 10GBASE-T - both of which allow some per-lane accounting

(errors or SNR). The committee must decide what accounting it wants and 
define the management parameters accordingly.


David Martin wrote:

>As Hugh pointed out, there is the clause 57 link OAM that might be a
>starting point for addressing your requirements. Note though, that it
>resides above the MAC. 
>For most of the PHY proposals in front of the committee there are
>several physical lanes/links (e.g., 4x25G or 4x10G) associated with a
>single 100G or 40G MAC. 
>So the performance event notifications and flags (e.g., Errored Symbol,
>Link Fault) would apply over the aggregate of the physical lanes/links,
>unless there were extensions added to c57 to allow indications on a per
>constituent lane/link granularity, as well as support for the raw
>from the PHY lanes. 
>Which leads to another issue. For APL above the PCS, as in
>frazier_01_1106.pdf, the raw counts could be provided per PCS. For APL
>below the 64/66 PCS, as in gustlin_01_0907.pdf, the raw counts would
>need to somehow be provided per PMA physical lane (not virtual).
>So a question for clarification on your requirement is whether
>indications per constituent link granularity or overall aggregate are
>For reference, there is an EFM Link OAM (c57) tutorial at:
>	filename: efm_oam_tutorial_2004_03_31.pdf