Subject: Re: LDP request

From: [email-masked]
Date: Wed, 3 May 2000 18:20:57 -0400 (EDT)

Sreeni,

>        In the above the 4th paragraph says, labels are 
> preassigned  and
> distributed. How labels are preassigned and distributed even 
> before the

Please refer to the Section 2.2 "Operation of LSP tunnels" and
Section 3 "LSP Tunnel related Message Formats" in 
http://www.ietf.org/internet-drafts/draft-ietf-mpls-rsvp-lsp-tunnel-
05.txt.

> data packet has come to LER. If the labels are preassigned and
> distributed , when LDP request message is used.

Please refer to the section 2.6 "Label Distribution and Management" in
http://www.ietf.org/internet-drafts/draft-ietf-mpls-ldp-06.txt.

Lichung

----- Original Message -----
From: ksreeni <[email-masked]>
Date: Wednesday, May 3, 2000 6:36 am
Subject: LDP request

> Hi,
> 
> >     3.4.2 Request Driven Label Assignment
> 
> >   In this scheme labels are assigned in response to normal
> >  processing of request based control traffic. Examples of such
> >  control protocols are RSVP. As an LSR processes RSVP messages it
> >   can, as it makes or changes entries in its forwarding tables,
> >   assign labels to those entries.
> 
> >   Among the properties of this scheme are:
> 
> >  - The computational load of assignment and distribution and
> >    the bandwidth consumed by label distribution are bounded by
> >    the amount of control traffic in the system.
> 
> >  - Labels are in the general case preassigned. If a route
> >    exists then a label has been assigned to it (and
> >    distributed). Traffic may be label swapped immediately it
> >    arrives, there is no label setup latency at forwarding time.
> 
> >  - Requires LSRs to be able to process control traffic load
> >    only.
> 
> >  - Depending upon the number of flows supported, this approach
> >    may require a larger number of labels to be assigned
> >    compared with topology driven assignment.
> 
>        In the above the 4th paragraph says, labels are 
> preassigned  and
> distributed. How labels are preassigned and distributed even 
> before the
> data packet has come to LER. If the labels are preassigned and
> distributed , when LDP request message is used.
> 
>    Can somebody answer my query by taking an unlabeled L3 packet as
> input to LER.
> 
> thanks,
> Sreeni.
> 
> 
>