Re: Any implementation for LSP modifications?

["Xipeng Xiao" <xiaoxipe@cse.msu.edu>]

Nihal,

You don't necessarily need vendor support to do this, 
if you don't need to do this in real time (in other 
words, if you can wait 5+ minutes before reacting).  
What you can do is creating a unix cron job
to check if there is any significant difference between
the RSVP bandwidth a lsp reserved and the actual amount
of traffic it is carrying.  If significant difference
exists, you will adjust the RSVP bandwidth of the lsp.

Based on my past experiences working with the MPLS System
at Global Crossing, I have 2 suggestions for you:

1. If you want to do this, it has to be done farely
infrequently, say on a daily/weekly basis.  A cron job
works very well for this purpose.

2. By adjusting the reserved bandwidth of the lsp, you create
a close-loop control.  You then have to think about you
want positive feedback or negative feedback.  Although
it's quite intuitive to adjust the RSVP bandwidth of a lsp
to match the actual traffic it is carrying, doing so creates
a positive feedback loop.  It may cause the system to become
less stable than using negative feedback, especially if
load balancing among multiple lsps are used.

XiPeng


> It would be very much appreciated if you could answer the following question
> regarding dynamic network resources management as an application of LSP
> modification.
> 
> Our intention is to use crldp-modify or RSVP-TE as a dynamic resource
> reservation method.  In this case provider edge router may need to implement
> a monitoring tool to measure usage of the lSP and increase/decrease resource
> (say bandwidth).  I was wondering whether there is any implementation by an
> equipment manufacture to support this.  I heard about the AutoBandwidth
> Allocator from Cisco, is there is any off line management tool available?.
> 
> Many thanks 
> Nihal Samaraweera.
> Senior Systems Engineer,
> PBN Design Team,
> Core Network Development (Technology), 
> Vodafone Limited, UK.
> TEL: +44 1635 685927
> Mobile: +44 7884 230941
>