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Re: [RPRWG] Phy Layer question




Vasan, 

With my Chair hat on.

A SONET framer does not have to be de-featured to work with an
RPR MAC. It is my technical opinion that 802.17 will not use
every feature of SONET but that there is no advantage 
to trying to create a reduced functionality SONET framer.
There are plenty of SONET chips out there and no-one will
want to redesign and reverify to save a few thousand gates.

We want 802.17 to flow packets through SONET clouds, DWDM
clouds and dark fiber. Therefore, we want to make sure we
do not throw away any features of the layer 1 that are
required to operate in the appropriate environment.


With my Cisco Hat on.

SRP does not use K1/K2 or any of the SONET APS signalling. 
It uses the SONET frame as a way to get a PDU from one 
node to the next. Most of our customers prefer SONET to 
GE due to the performance monitoring features.

That being said, SRP can work in a SONET cloud when provided
with a protected circuit and the SRP protection mechanism
can be configured to allow Layer 1 to try to protect first.
We do not encourage this mode of operation and suggest to
customers that they use unprotected circuits and allow SRP
to do the protection.

cheers, 

mike


-- 
Michael Takefman              tak@xxxxxxxxx
Manager HW Engineering,       Cisco Systems
Chair IEEE 802.17 Stds WG
2000 Innovation Dr, Ottawa, Canada, K2K 3E8
voice: 613-271-3399       fax: 613-271-4867

> I am new to the group.  I have been reading  up the presentations. I have a simple question.
> We are saying .17 will be layer 1 agnostic.  However, (if sonet is the phy used) sonet is aware of the
> ring structure - for APS, etc.
> Will the .17 specify how a sonet framer should be defeatured to work with a RPR MAC? 
>  
> Thanks,
> Vasan Karighattam
> Architect
> Intel Corporation
> 9750 Goethe Road
> Sacramento, CA 95827
> (916)855-5177  x4907