Subject: Re: Traffic Parameters negotiation

From: "Srinivasan.E.S." <[email-masked]>
Date: Sun, 31 Oct 1999 23:08:37 -0500

Hi Andrea,

     By way of traffic parameter negotiation, the LSRs come to an understanding
of the exact nature of the services provided to a particular LSP among them.
CR-LDP provides hooks in terms of specifying the traffic parameters in an LSP
setup.

LSR1----------LSR2---------------LSR3

When LSR1 initiates a CR-LSP towards LSR2, involving certain traffic parameters
as constraints, in can indicate the (sub)set traffic parameters of as
negotiable, meaning that it expects to setup LSP with those specified values,
but OK if those values may not be provided by LSR2 exactly. i.e, Those
parameters form the maximum values for the particular LSP in consideration, and
if LSR2 can not support the specified maximum, it can alter (decrease only) the
values of the traffic parameters to its supported values and forward it. So, the
LSP will be setup with those modified set of traffic resources along its path.
The return response to LSR1 will contain the modified traffic resource
parameters and it is left completely to the discretion of the LSR1 to
accept/tear down the LSP based on some criteria (e.g, policies). Unfortunately,
the CR-LDP does not have provisions to specify the Max/Min values for the
traffic parameters of an LSP in case of negotiations so that the other LSRs can
have a way of knowing what is the expected range from the ingress side?

Hope this answers to your question to some extent.

--Srinivasan.E.S.

Andrea Tricco wrote:

> Hi all,
>
> in draft CR-LDP, section 4.3.2.1:
> "if a Traffic Parameter is indicate as negotiable in the Label Request
> Message, then an LSR may replace the Traffic Parameter value with a smaller
> value"
>
> Can anybody clear me the process of Traffic Parameter negotiation?
> What is the Message that LSR send to replace the Traffic Parameter value
> with a smaller value?
>
> Thank in advance.
>
> Andrea.