Subject: RE: PWES or AC

From: "Hamid Ould-Brahim" <[email-masked]>
Date: Wed, 24 Sep 2003 14:40:12 -0400

Stewart,

> 
> A little grepping suggests that as a group we use
> PWES slightly more often in our documents than AC,
> and so I propose that we standardise on PWES.
> 
> Is that OK with everyone?
> 

I think l2vpns proposals use more often AC than PWES
It would have been good to have the same terminology 
used in both WGs.

AC acronym is as well related to AI acronym (Attachment
identifier particularly when the identifier of AC can identify the
forwarder - for VPWS). A change to AC acronym may imply a 
change/new AI acronym as well. I personally prefer keeping the 
AC, AI acronyms.

On the same subject:

PWES is defined in arch draft as:

"PW End Service       The interface between a PE and a CE.  This
   (PWES)               can be a physical interface like a T1 or
                        Ethernet, or a virtual interface like a VC
                        or VLAN."

My first suggestion is to replace "like a VC" in this
paragraph with "like an ATM VCC or FR DLCI or Ethernet VLAN" 
just to make it consistent. 

Note that the "VC" acronym is not defined in the arch document 
(though it is used in couple of places in PWE3 documents and 
sometimes to mean different things).
 
At one time the VC is used to refer to AC/PWES such 
as in:

"Attachment Circuit   The circuit or virtual circuit attaching
   (AC)                 a CE to a PE."

and sometimes it is used to refer to the PW such as in:
(control draft, VCCV draft, etc):

- "OAM cells MAY be transported on the VC LSP..."
- "VC info Length" in the encoding.
- "When a PE signals a PWE3 VC and desires OAM for that VC..."
...

And even sometimes it is used to refer to the "end-to-end
emulated service" such as described in FR-MPLS draft.

My suggestion is to fix as well the AC/PWES/VC/PW usage in all l2vpn 
and pwe3 docs. A proposal is:

a) keep the relevancy of the term VC and its usage just 
   for FR/ATM related drafts/sections (since this term is
   well known for these services) and
b) use only AC/PW/AI in all the other PWE3 and l2vpn 
   documents/sections.

Hamid.