Subject: PWE3 state information in context to ATM

From: "Roy, Anindya (Anindya)" <[email-masked]>
Date: Mon, 22 Mar 2004 10:00:42 -0500

-----Original Message-----
From: Sasha Vainshtein [mailto:[email-masked]]
Sent: Monday, March 22, 2004 8:15 AM
To: 'Yaakov Stein'; [email-masked]
Cc: [email-masked]
Subject: RE: [PWE3] Proposed change to 5..4.1 of PWE3 architecture

Yaakov, Stewart and all,
Please see inline.

With best regards,
                                   Sasha Vainshtein
email:     [email-masked] <mailto:[email-masked]> 
tel:       +972-3-7659993 (office)
           +972-8-9254948 (res.)
           +972-58-674833 (cell.)

> -----Original Message-----
> From: Yaakov Stein [mailto:[email-masked]]
> Sent: Monday, March 22, 2004 1:21 PM
> To: Sasha Vainshtein; [email-masked]
> Cc: [email-masked]
> Subject: RE: [PWE3] Proposed change to 5..4.1 of PWE3 architecture
> 
> 
>  
> > [Sasha] The above-mentioned explicit reference to the 
> > MPLS-in-IP spec would make it clear that using an MPLS label 
> > as a demultiplexer actually makes PWs using them MPLS PWs 
Hi All,
	 
Would like to get the groups view on the following issue.

PWs can fail in a single direction or in both directions.However this may not be acceptable when the PWE3 are used to emulate ATM Layer2 connections, to maintain the integrity of the  bidirectional property of ATM connections.

My understanding is in order to preserve the integrity of the BI-DIRECTIONAL property of ATM VC/VP, any or both of the  following MUSTBE supported.

(1) If a PWE3 is emulating a ATM Layer 2 service, the PW must be bound to a *bi-directional* PSN tunnel because of the ATM's  bidirectional connection properties ?

(2) Incase the PW is allowed to setup over two disjoint unidirectional tunnels in each direction, then the implementation must maintain state information of both the tunnels in order to synchronize the operational state of the ATM VC's in both the  direction to handle situations of PSN failures in single direction.

If there is already a proposed solution can someone please provide a pointer.

Thanks.
Anindya