RE: GMPLS issues (was - GMPLS Last Calls)

[John Drake <jdrake@calient.net>]

Also, an ATM service using NSAP addresses for customer ports could be built
on top of a GMPLS core using IP addresses internally.  The ATM service
delivery switches could use the GMPLS core to provison lighpaths between
themselves and then run
PNNI as an overlay network for purposes of exchanging NSAP reachability
information. 

-----Original Message-----
From: Mannie, Eric [mailto:Eric.Mannie@ebone.com]
Sent: Wednesday, June 13, 2001 7:33 AM
To: 'neil.2.harrison@bt.com'; ananth.nagarajan@mail.sprint.com;
BRaja@tellium.com
Cc: wesam.alanqar@mail.sprint.com; ccamp@ops.ietf.org;
Tammy.Ferris@mail.sprint.com; mark.jones@mail.sprint.com; mpls@UU.NET;
lynn.neir@mail.sprint.com; andy.bd.reid@bt.com; alan.mcguire@bt.com
Subject: RE: GMPLS issues (was - GMPLS Last Calls)


Hello Neil,

>Given that the layers have to be decoupled in the general case (for
>commercial as well as technical reasons - see the BT 'Freeland'
requirements
>draft to 12/00 mtg) then there seems to be no reason why an operator could
>not use NSAPs for the access points of SDH or OTNs if he so wished.  And,
>given this choice, that operator might also prefer to use PNNI as the
>signalling/routing solution too.  So, the issue seems not one of
>'necesssity' but simply choice......though there may be certain technical
>benefits of choosing 1 solution over another.  I don't believe there is
>anything technically wrong with saying this and giving operators/vendors a
>choice here is there?.....if there is please point out the problems.

If somebody wants to use PNNI, it is not our business. The choice between a
GMPLS control plane and a PNNI control plane is not in our scope. We are
here working on GMPLS at the IETF, not on PNNI at the ATM Forum and not on
G.ASON at the ITU-T.

GMPLS comes with IPv4 and IPv6 addresses and PNNI comes with NSAP addresses.
I don't think that somebody will choose a control plane only because it uses
IP or NSAP addresses, this doesn't make sense to me. There are much more
important distinctions between the two control planes than the format of the
addresses.

Technically I don't see arguments to adapt GMPLS to NSAP addresses, or to
AppleTalk addresses or to any kind of addresses that some people could
prefer, or that could come from another standardization body.

If technically there is a clear benefit of using NSAP addresses instead of
IP addresses in GMPLS that should be demonstrated by somebody. Up to now
nobody made it (I think that when somebody wants to modify an existing work
in a standardization body this has to be justified with technical reasons,
not just by a personal preference). So I presume that there is today no
technical argument to use NSAP addresses in GMPLS.

Even if any benefit is demonstrated, that should be balanced with the
disadvantages of supporting it and finaly the IETF should decide if they
want to adapt their protocols to other addressing schemes. Personally, I
don't think that this make sense.

Moreover, GMPLS is IP centric and this is one of its driving forces. I don't
see the interest of transforming an IP centric control plane in a less IP
centric control plane. This is going in the opposite direction of what we
are trying to do.

Kind regards,

Eric

Eric Mannie
EBONE (GTS)