Subject: RE: [TE-wg] TE use in today's networks

From: "Naidu, Venkata" <[email-masked]>
Date: Sun, 27 May 2001 15:02:06 -0400

Shawn,

  I would say, traffic engineering is not widely 
  deployed at the core. But remember we are always
  ahead of what industry chooses.  

  The need for TE comes when ISPs has less bandwidth
  and would like to manage bandwidth more efficiently
  than their competitors.

  Most ISPs reporting 2.5 - 15% utilization of their 
  backbone, it is hard to come up with a mathematical case
  that a serious network problem exists in the networks
  that are worried about traffic engineering.

  http://www.slac.stanford.edu/comp/net/wan-mon/surveyor-vs-ripe.html

  But, plain old IP routing won't provide TE. Fortunately
  MPLS Constraint-Based Routing implicitly solves TE problems
  along with fast rerouting and application to QoS/GoS.
  MPLS supports, rather than extends, the IP QoS model.
  Other major applications of MPLS is VPN support.

  You can find useful information about TE at:  

  http://www.cse.msu.edu/~xiaoxipe/

  Previously, vendors had proprietary methods but the
  increased L1/L2 technologies providing high bandwidths
  obviates the need for TE. TE-WG has minimum requirements 
  & recommendations for applicability:

  http://www.ietf.org/internet-drafts/draft-ietf-tewg-framework-04.txt  

--Venkata Naidu 

-> Hi,
-> 
-> I'm a student currently researching TE technologies (mainly 
-> using MPLS). 
-> With all the proposed methods and functionalities, I was 
-> wondering if anyone 
-> has some useful information/pointers to answers to the 
-> following questions:
-> * How widely is traffic engineering over MPLS deployed in 
-> today's networks?
-> * What applications of TE are in use today (protection, congestion 
-> management, etc)?
-> * How widely used are offline planning tools?
-> * How do different vendors affect different deployments? 
-> That is, are the 
-> common functionalities mostly in use, or are there different 
-> proprietary 
-> methods used in different networks/SPs?
-> 
-> Thanks a lot for any useful information,
-> Shawn.

---

From: Randy Bush <[email-masked]>
Date: Sun, 27 May 2001 19:39:02 -0700

>   But, plain old IP routing won't provide TE.

you may want to look at some of the recent literature on this subject which
does not support the above conclusion.

randy

---

From: Alan Hannan <[email-masked]>
Date: Sun, 27 May 2001 20:53:08 -0700

To which literature do you refer?

  I am aware only of the OMP paper which does not qualify
  as 'plain old IP routing'.

  -alan

Thus spake Randy Bush ([email-masked])

---

From: Florian-Daniel Otel <[email-masked]>
Date: Mon, 28 May 2001 10:38:50 +0200 (MEST)

> does not support the above conclusion.

(Joining the chorus): Can you Cc: the list pointers to the mentioned
literature ? 

> randy

Regards,

Florian

---

From: Randy Bush <[email-masked]>
Date: Mon, 28 May 2001 06:30:27 -0700

> notice that what literature says is one thing and what shipping code
> from major vendors can do today to solve real issues is quite another
> one.

you said it, not i

randy

---

From: Alan Hannan <[email-masked]>
Date: Mon, 28 May 2001 10:30:32 -0700

I suspect that one of the papers referenced is:

	http://infocom.ucsd.edu/papers/744.pdf

 There are serious considerations to be overcome before 
 this is practically implementable (ie, 10 significant digits
 on routing metrics).

 Additionally, there are subsequent ops problems with
 implementing it (ie, dramatic impact when one link drops).

 I suspect that this issue has been hammered to death on
 a mailing list somewhere, anone have pointers?

 -alan

Thus spake Florian-Daniel Otel ([email-masked])