Subject: [Idr] draft-ck-bgp-atm-nlri-01.txt

From: [email-masked]
Date: Fri, 17 Dec 2004 10:21:29 -0500

Hi,

The draft looks good. I just have few comments:

- "the introduction of an MPLS core creates a topological challenge that
does not exist
   in traditional ATM networks. The overlay approach results in a full
   mesh of O(N*N) PNNI routing adjacencies, where N is the number of ATM
   switches that directly connect to the MPLS core. Each ATM switch that
   is directly connected to the MPLS core has to deal with O(N)
   adjacencies, where N can be quite large, thereby imposing a scaling
   burden on its ATM control plane."

  This  is not necesarily required. You can have a partial mesh of PNNI
trunks over MPLS PWs,
 However, this will lead to having the ATM switches terminating these PNNI
trunnks to become transit That is they will
have to do MPLS PW-ATM- MPLS PW interworking. what is your view on that?
 However, I do think that  PNNI adjacencies in this case (although this is
not restricted to PNNI) adjacencies are a scalability
factor and if you are interconnecting a large set of ATM clouds and you
want  to have direct reachability among these clouds without
using another cloud or the border of another cloud as transit nodes for
various reasons, the number of PNNI adjacencies will become a factor that
is
cofounded with the size of the network. Having the capability to alleviate
this problem by distributing ATM reachability via BGP is  and requiring
a switch to have one, two or few BGP peering sessions with two or more
route reflectors instead of a PNNI adjacency with every other switch is an
advantage although this shifts some of this load to the RR.

- The next hop address for an NLRI: you mention it can be any IPv4, IPv6 or
NSAP address. Do you think that it makes sense to require it to be an IP
address only?
   It seems to me reasonable to do that . Is there is need to have an NSAP
address? In addition, it is not stated clearly how the next hop address
would be encoded. Wouldn't
this be dependent on the address family?

- ATM reachability type: doesn't this have to be assigned by IANA?

- Site of origin attribute: you leave this ptional. Is it possible to
elaborate on the need for it and what is the consequence if not included.

- "The RD used by a PE must be unique, and can either be preconfigured or
auto-generated
   based on PE's attributes like configured autonomous system (AS) and
   IP addresses."

   RD containing IP address depends on whether the AS is 4 bytes or 2
bytes.

Thanks,
Nabil

_______________________________________________
Idr mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/idr