Subject: Re: Concerns regarding the numerous layer violations in base MPLS drafts

From: Kireeti Kompella <[email-masked]>
Date: Wed, 20 Dec 2000 10:07:52 -0800 (PST)

Hi Dan,

> Folks who remember [1] think that having special procedures for IPv4 LSPs 
> is perfectly reasonable.

I have no objections to special procedures for IPv4 LSPs.  What I want
to make clear is that we agree what LSPs are IPv4, and that special
procedures are limited to IPv4 LSPs.  Also, suggesting that the
procedures be done at the LSP ingress rather than in midstream is not
quite the same as saying that the procedures are unreasonable.

> Folks who focus on [2] worry about "layer violations"
> 
> Folks who focus on [3] don't even worry about the issue, since "non-packet 
> capable devices" never see packets.

Not quite true.  Non-packet LSRs have a G-PID (generalised PID), and
one thing that GMPLS must make clear is how the G-PID gets used,
especially when tunneling LSPs through LSPs.  Different worry, but it's
still there.

> Right now Kireeti is feeling gored because he wants to transfer L2 packets 
> over IPv4 LSPs, and doesn't want to worry about IPv4 procedures.

Small correction:
a) I don't particularly want to transfer packets anywhere :-)  Okay, maybe
   this email ....
b) I have more customers wanting to transfer IPv4 packets than L2 packets
   over LSPs.  IP rules, that's just a fact.

> However, if he gets his way on the above then I predict that he, or someone 
> else in his company, will feel equally gored the first time a customer 
> deploys VPN, or LDP over TE, or Aggregated TE, or ..., and needs to debug a 
> problem using traceroute, or wants to apply some other IPv4 procedure.

Gosh, I'm gored again (or bushed with this discussion? :-)):  I do have
customers doing LDP over TE.  And those asking about aggregated TE, and
many pounding on our doors for VPNs ...  In your classification above,
I fall under [1], [2] *and* [3] ... and still worry about the problem.

Note that if the problem is traceroute (we keep coming back to this),
how about solving the traceroute problem properly?

Kireeti.

---

From: Dan Tappan <[email-masked]>
Date: Wed, 20 Dec 2000 14:05:46 -0500

>how about solving the traceroute problem properly?

I deliberately said "IPv4 procedures" to avoid getting bogged down in the 
traceroute discussion (and so as to cover everything from traceroute, to 
fragmentation, to loadsharing, to other features not yet specified).