Subject: RE: Last Call for LDP

From: "Punj, Arun" <[email-masked]>
Date: Fri, 9 Jun 2000 12:45:50 -0400

Hi Allison,

IPsec SA between peers should solve security requirement,
which is not mandatory in any case. 

As for "horses, for courses" requirements, it would seem 
to me that SCTP is meant for packet oriented signalling
protocols, which is what LDP is.

may be I am missing something.

Arun

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Friday, June 09, 2000 12:40 PM
To: Punj, Arun
Cc: [email-masked]
Subject: re: Last Call for LDP

Hi,

> Any reason why LDP can't use SCTP ( sigtran ) instead of TCP ?

One reason is that the TCP MD-5 usage called for in LDP is a
well-established peer trust mechanism and there's not been any
deployment of SCTP security yet.

> And it would be far more light weight if it used SCTP.

SCTP isn't lighter weight than TCP, but has different services
to meet different requirements.

Allison (TSV Co-AD)

---

From: Dave Katz <[email-masked]>
Date: Fri, 9 Jun 2000 10:12:22 -0700 (PDT)

It is less likely for a protocol to reach the "working code" half of
the IETF mantra if it also requires going off and implementing
(typically in the kernel environment) another transport protocol when
there is already one universally available that works just fine.
"Lighter weight," whether true or not, is an uninteresting
optimization unless TCP proves to be too "heavy."  (From an
implementation standpoint, STCP is decidedly not "lighter weight"
because it requires effort greater than zero.)

And transport protocols are notorious for being much harder to implement
well than they look at first glance.

--Dave

   Hi Allison,

   Arun

   -----Original Message-----
   From: [email-masked] [mailto:[email-masked]]
   Sent: Friday, June 09, 2000 12:40 PM
   To: Punj, Arun
   Cc: [email-masked]
   Subject: re: Last Call for LDP

   Hi,

   Allison (TSV Co-AD)

---

From: Grenville Armitage <[email-masked]>
Date: Fri, 09 Jun 2000 10:37:43 -0700

"Punj, Arun" wrote:
	[..]
> may be I am missing something.

That TCP is already widely implemented?

cheers,
gja

---

From: "Loa Andersson" <[email-masked]>
Date: Fri, 09 Jun 2000 19:46:44 +0200

All,

this was something we discussed quite a bit in the LDP design team
the first and second meeting. The reason was that ARIS (the early
IBM implementation) run directly over IP and implemented a 
reliable transport of its own.

We decided to to use TCP because it was readily available and well
known.
It has been in the LDP spec since 97 and was slightly discussed at the 
Washington meeting that year. It has since then - through WG Last calls 
and IESG last call and been generally accepted.

IMHO there are to many divergencies in the Label distribution area, to 
make yet another one useful. 

> well than they look at first glance.

/Loa

-- 

Loa Andersson
Director Routing Architecture Lab, EMEA
St Eriksgatan 115A, PO Box 6701
113 85 Stockholm, Sweden
phone: +46 8 50 88 36 34,   mobile + 46 70 522 78 34
e-mail: [email-masked]