Subject: Constraint Based Routing

From: "Rajesh P Jain" <[email-masked]>
Date: Tue, 16 Oct 2001 18:28:14 +0530

"Hi",
	Can anyone explain me what exactly is "Constraint-Based Routing" (CBR) ?

	Please correct me if I am wrong. I feel that RSVP-TE, CR-LDP, CSPF (the
protocols like RSVP, LDP and OSPF) having extension for Traffice-Engineering
can synomously used for "CBR" since the constraint are specified while
setting up the LSP.

	Also, please give a list of protocols which needs to be extended for "CBR".
TIA,
	Rajesh P Jain

---

From: Ajay Simha <[email-masked]>
Date: Tue, 16 Oct 2001 11:34:54 -0400 (Eastern Daylight Time)

On Tue, 16 Oct 2001, Rajesh P Jain wrote:

RPJ>"Hi",
RPJ>	Can anyone explain me what exactly is "Constraint-Based Routing" (CBR) ?
RPJ>
RPJ>	Please correct me if I am wrong. I feel that RSVP-TE, CR-LDP, CSPF (the
RPJ>protocols like RSVP, LDP and OSPF) having extension for Traffice-Engineering
RPJ>can synomously used for "CBR" since the constraint are specified while
RPJ>setting up the LSP.

Rajesh,

There is the PCALC for which the IGP flooding is used at headends when the
path is computed based on the constraints.  RSVP/CR-LDP comes later to signal
and reserve the needed bandwidth and get labels for the PATH.

-ajay

RPJ>
RPJ>	Also, please give a list of protocols which needs to be extended for "CBR".
RPJ>TIA,
RPJ>	Rajesh P Jain
RPJ>

-- 
Ajay Simha
MPLS Deployment Engineer
IOS Technology Division
(919) 392-3141

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