Subject: Any implementation for LSP modifications?

From: <[email-masked]>
Date: Fri, 6 Jul 2001 08:58:15 +0100

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

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From: "Xipeng Xiao" <[email-masked]>
Date: Fri, 6 Jul 2001 10:49:11 -0700

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

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From: Changhoon Kim <[email-masked]>
Date: Sat, 07 Jul 2001 09:49:10 +0900

Nihal,

As fa as I can tell, most MPLS implementations provide (near realtime) LSP-level
traffic monitoring results, such as accumulated number of packets & bytes, with
operators. JUNOS does that by CLI or statistics logging files, and Cisco also
does that by CLI. As XiPeng said, monitoring these values in a regular-basis,
and adjusting LSP bandwidth consequently would be the best and the easiest gear
for MPLS TE.

But, if you really want to know how much the traffic amount from this ingress to
that egress would be even before deploying a simple LSP between the two, you can
resort to NetFlow like monitoring schemes, OCxMon, and/or RTFM probes with (a)
really powerful analysis tool(s); You must analyze the hop-by-hop flow traces.
You may also find something interesting  in Cisco TMS (Traffic Matrix
Statistics).

And for off-line (MPLS) TE tools, you may as well check WANDL, NetMaker of
Makesystems, QualNet by Scalable Network Technologies, and a lot more, even
though most of them do not care much how to measure and how to draw accurate
traffic demand (matrices).

Chang

--
Changhoon Kim

Dept. of Internet Technologies
Electronics and Telecommunications Research Institute (ETRI)
Daejeon, KOREA
Tel) +82-42-860-5801
Fax) +82-42-860-5440

***
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