Subject: RE: A question regarding section 5.1.1.2 of draft-ietf-l2vpn-sign alin g-00.txt

From: [email-masked]
Date: Wed, 10 Sep 2003 15:34:50 +0100

> From the first paragraph of section 5.1.1.2: 
> 
> The  local  name consists  of  a  VPN-id (signaled  as  
> the  AGI) and  an> Attachment Individual Identifier 
> which is unique relative to the AGI. 
> 
> So the situation in which you have two <V, fred>'s is not 
> allowed.

When I read this I took it to mean unique on a per PE basis rather than on a
per VPN basis, perhaps the draft should state this?

This leads me onto a question on a similar theme to a question I have posted
on the PWE3 mailing list. What values/names are intended to be used as AI's?
An example given in draft-ietf-pwe3-control-protocol-03.txt is
"ATM3VPI4VCI5". As its possible for two Attachment Circuits on different PEs
(but belonging to the same VPN) to have exactly the same interface/VPI/VCI
values, this is obviously not a good ID to use because it may not be unique
within a VPN. Of course a service provider could put processes in place to
avoid the use of identical IDs within a VPN, e.g. move one of the Attachment
Circuits over to a different VPI/VCI, but this is extra work and mistakes
can happen.

Why not just use the PWid FEC element and use the combination of the PE IP
address and PWid to identify the VPN endpoints? What problem(s) does the
Generalised ID FEC element solve that justifies the extra
configuration/management required in associating an Attachment circuit with
a VPN ID (AGI) AND an endpoint ID (SAII/TAII)?

Thanks,

Richard

---

From: Sasha Vainshtein <[email-masked]>
Date: Wed, 10 Sep 2003 17:37:37 +0200

Richard and all,
Please see some comments 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: [email-masked] [mailto:[email-masked]]
> Sent: Wednesday, September 10, 2003 4:35 PM
> To: [email-masked]; Sasha Vainshtein
> Cc: [email-masked]
> Subject: RE: A question regarding section 5.1.1.2 of 
> draft-ietf-l2vpn-sign alin g-00.txt 
> 
> 
Looks like we have both made the same mistake. The draft actually states
that the names are unique within the specific VPN, but still calls the name
"local". 
... snipped to the end...