Subject: Re: [IPFIX] SCTP - IP Flow

From: Simon Leinen <[email-masked]>
Date: Tue, 27 Feb 2007 13:38:33 +0100

Guillaume FORTAINE writes:
> Happy New Year to you.

Guess this shows that I don't look into the IPFIX list often enough...

> I would greatly appreciate to ask to you some questions :

> Would not it be SCTP the best Transport protocol for NGNs ?

(Isn't SCTP the best Transport protocol, period? :-)

> And is ipfix related to your concept of IP Flow router ?

Flow-based routing is an old idea, and was at the origin of NetFlow
and LFAP, two precursors of IPFIX.  I think it came up during the
years of crazy traffic growth in the mid-nineties, when router vendors
struggled to keep forwarding capacities growing in line with demand.

At least for NetFlow, the idea of flow-based routing (forwarding) was
abandoned quickly, and NetFlow was mostly kept around for accounting
only.  The problem was that the flow cache didn't scale to core
network nodes and their high numbers and setup frequencies of flows.

You can make flow-based accounting scale by introducing sampling, but
this doesn't work quite so well for forwarding.

> http://www.packet.cc/files/FlowPaper/NextGenerationofIP-FlowRouting.htm

I'm a bit disappointed that this paper doesn't mention related work
such as Ipsilon's flow-based switching work (see RFC 1953 from May
1996), or NetFlow (which started out as a flow-based forwarding
cache), or other flow-based approaches, most of which fell out of
fashion.  I'm not saying flow-based forwarding is a bad (or good)
idea, but it is certainly not a new idea.
-- 
Simon.

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From: Simon Leinen <[email-masked]>
Date: Tue, 27 Feb 2007 13:38:33 +0100