Re: draft-bonica-tunneltrace-02

[Eric Rosen <erosen@cisco.com>]

Shahram> What is  the difference between ATM,  FR, or any  CO technology and
Shahram> MPLS 

Well, for  one thing, MPLS  isn't a CO  technology.  It's got lots  of stuff
that doesn't really  make sense from a CO perspective.   Of course, when the
CO  guys  run  across  these  features  (multipoint-to-point,  php,  liberal
retention, independent  mode, equal  cost load balancing,  dynamic rerouting
with no signaling,  ttl, lack of packet sequencing,  IP control plane, etc.,
etc.) they assume that those features are there by mistake!

This misconception  that MPLS  is a CO  technology, shared  as it is  by the
"pure  IP" crowd and  by the  ITU/ATM crowd,  is the  source of  much wasted
time.  

MPLS is  actually an IP-derived technology that  facilitates the application
of  certain   circuit-like  characteristics  to  IP  networks.    As  an  IP
technology,  the usual  IP diagnostic  tools, such  as ping  and traceroute,
should be applicable.   That's what this whole useless  discussion is about.
One  the one  side are  people  who think  that IP  networks are  inherently
unmanageable (after all, they don't  follow ITU standards), and on the other
side are people who think that the IP-based paradigms are the best. 

It is true that  MPLS can be used to provide something  which is very like a
CO network,  but it  doesn't have to  be used  this way, and  usually isn't.
Those of use  who are not particularly interested in  CO networks just don't
want to be saddled with the  legacy CO mechanisms.  Presumably, if all these
legacy CO mechanisms were  so great there would not be such  a great rush to
IP.