RE: [PWE3] PWE Service interworking

["Hamid Ould-Brahim" <hbrahim@nortelnetworks.com>]

Eric,

[clipped]...

> I think this is the same as you indicate in your example:
>
>      CE--FR--PE--FR/PW/PSN--PE-IWF-ATM-CE
>

I think you meant something like:

 

      CE--FR--PE--FR/PW/PSN--PE-FR-IWF-ATM-CE

                                ^^

> Is there anything more to say about it?
>
> In  the special  case where  the  payload is  always IP 
> datagrams, but  the
> ingress  and  egress  ACs  use  different data  link 
> protocols,  then  "ARP
> Mediation" can  be used  for interworking, as  long as  there
> is no  need to
> provide any sort of faithful data  link emulation.  This
> seems to be the one
> case that might be of interest to the IETF.
>

 

I have no problem with IP-only interworking approach when

there is no available interworking function to use

(outside the pw), particularly if most of the traffic carried

over a PW is IP. However, my questions probably best answered

by the providers deploying pws where both attachment circuits

are of different protocols are:

 

a) Are there applications/situations where

   even if the payload is IP, the client requires the

   provider not to make any assumption on the payload

   (maybe situations of regulatory scenarios)?

 

b) For the case where the provider has upgraded his l2 network

   to MPLS/IP and the native l2 services are replaced with PWs,

   can the provider guarantee/assume in all cases that the traffic

   is always IP, or can he assumes that on any given PW there is

   no case where both IP and non IP traffic are being sent (since

   the upgraded service initially didn't make that assumption,

   or maybe the provider can't tell whether it is always

   IP since it doesn't control customer devices)?

 

c) Is there a situation/application even for IP only

   interworking/payload where items like sequencing, etc

   need to be supported as part of the service being

   interworked?

 

Regardless what solution is provided and even in what

appropriate standard body that solution needs to be pursued

it will be good to have an overall view on what category and

percentage the interworking scenarios fall into.

 

Hamid.