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Re: [BULK] VCAT/LCAS draft update...

Hi folks, the differential delay compensation capability is a property of VCAT (not LCAS) hence independent of whether LCAS is implemented or not. In SDH the MFI is used with VCAT (part of the H4 byte).
This issue has come up before. And at the time it seemed to belong with some the MLN work that kept track of "adaptation" properties. Right now it seems that differential delay compensation limits would need to be handled by network planning rather than the control plane. 

Regards

Greg


Huub van Helvoort wrote:

Hi Jishnu,

you replied:


Adding to Hubb's reply below
The MFI field in LCAS allows support upto a maximum of 256ms differential delay compensation for HO VC. But the exact value is completely depending on 
the vendor implementation and can be anything between 125us to 256ms.


This is information that is well known.

Reading your initial email again I am confused by the
additional reponse.

Can you please inform us of what the issue is that you
would like to resolve.
And make a distinction between the two modes:
==  VCAT without LCAS
==  VCAT with  LCAS.

Thank you, Huub.


-----Original Message-----
From: Huub van Helvoort [mailto:hhelvoort@chello.nl] Sent: Tuesday, December 02, 2008 9:34 PM 
To: BRUNGARD, DEBORAH A, ATTLABS
Cc: Jishnu A; Greg Bernstein; ccamp
Subject: Re: [BULK] VCAT/LCAS draft update...
Importance: Low

Hi Deborah,

You replied:


Shouldn't be a problem if the data plane is based on ITU - so it would
need to support (at minimum) ITU's G.707 minimum differential delay
requirements for VCAT.


Minimum delay in G.707 is 125 usec (micro-seconds)...

Maximum differential delay depends on implementation.
Differential is the difference between the largest
propagation delay of one of the members and the
smallest propagation delay of one of the members.
The sink VCAT/LCAS function is capable of detecting
and reporting whether one or more members does not fit
the differential delay capability.

Cheers, Huub.


-----Original Message-----
From: owner-ccamp@ops.ietf.org [mailto:owner-ccamp@ops.ietf.org] On
Behalf Of Jishnu A
Sent: Tuesday, December 02, 2008 10:03 AM
To: 'Greg Bernstein'
Cc: 'ccamp'
Subject: RE: [BULK] VCAT/LCAS draft update...

Dear Greg,
One additional problem with VCAT/LCAS is the amount of differential
delay
supported at the destination node. Can it be mentioned as a note that
co-routing or diversely routing is also based on the availability of
enough
sufficient differential delay buffer size at the destination node?
Regards,
Jishnu A

-----Original Message-----
From: owner-ccamp@ops.ietf.org [mailto:owner-ccamp@ops.ietf.org] On
Behalf
Of Greg Bernstein
Sent: Wednesday, November 19, 2008 12:07 AM
To: ccamp
Subject: [BULK] VCAT/LCAS draft update...
Importance: Low
Hi folks, I edited the VCAT/LCAS draft to use the CALL_ATTRIBUTES object 

from the MLN extensions draft.
We define a new VCAT TLV for use in the aforementioned object. All procedures and encodings otherwise are the same as the previous draft. Note that the draft will now be contingent on the MLN extensions draft moving forward. 

A URL for the Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-vcat-lcas-06. 
txt


Regards

Greg







--
===================================================
Dr Greg Bernstein, Grotto Networking (510) 573-2237