Re: [ns] a question on Nortel DiffServ!

[Sudhindra Suresh Bengeri <ssbenger@unity.ncsu.edu>]

Try this and let me know if it works:

For the code point which carries EF traffic its better to use the token
bucket policer since u only want to know if traffic is In or Out of
profile. (The policer entry would require one downgrade CP). Add the PHB
entry say some thing like (10 -> in and 11 -> out)

$que addPHBEntry 10 0 0
$que addPHBEntry 11 0 1

and corresponding config Q could be
$que configQ 0 0 <appropriate min> <app max, could be same as min> <low>
$que configQ 0 1 0 0 1 <= this should drop nearly all packets w/ CP 11

For other code points add whatever policer, scheduling mechanism u want.

Well even I had tried the DROP mode which works but dun really emulate EF
requirement.

HIH.

Regards,
Sudhin.

On Thu, 12 Apr 2001, Sowmya Manjanatha wrote:

> Hi all,
>
> I have been trying to simulate a strict policing scheme (EF) out of the
> Nortel DiffServ module. I have a topology with 12 sources/dest, 6 edge
> routers and 2 cores.  The topology is dumb-bell shaped with sources and
> destinations on either side of 3 edge routers connected internally to
> 2 cores something as below :
>
>          s1                                d1
>           .  \                          /  .
>           .   \                        /   .
>          s4---- e1                    e4---d4
>                    \                 /
>          s5         \               /      d5
>          .   \       \             /     /
>          .    \       \           /     /
>          s8---- e2----  c1 --- c2 ----e5---d8
>                       /          \
>          s9          /            \        d9
>          .   \      /              \     /
>          .    \    /                \   /
>          s12---- e3                  e6 ---d12
>
>
> I have been using the PRI mode for the scheduler in the core. I have 3
> queues on the core and I set the QueueRate on each of the queues to a
> value of x, y an z.  What I want to see is that the routers drop all
> the packets beyond the max. rate of x.  I tried setting the drop
> probability on the queue using "$c1q configQ 0 0 10 20 1" to 1 with the
> intention of achieving the above.  I also have a TS3CWM policer on the
> edges and I have the PIR and CIR values set to a really low value.  But,
> the average rate I have been seeing is much above the rate of x.  The
> linkrate between c1 and c2 is set such that the total rate coming out
> of e1, e2 and e3 is higher than the linkrate.
>
> I even tried setting MREDMode to DROP but in vain.
>
> Am I missing something here?  Is there any way I can achieve the strict
> policing that I want (any specific policer, scheduler mode combination??).
>
> Any clues, suggestions??
>
> Thanks,
> Sowmya.
>
>
>
>
> *******************************************************************************
>
>     Sowmya Manjanatha : University of New Hampshire
>     Major             : Computer Science
>     ***********************************************
>
>     email        : sowmyam@cs.unh.edu
>
> *******************************************************************************
>
>

****************** Sudhindra Suresh Bengeri ********************
Graduate Research Assistant   | Home:                          |
to Dr. George N. Rouskas      | 2110, Gorman St.,              |
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NCSU, Raleigh, NC 27695       | Ph. (919) 852-1961             |
(919)515-3655(P) / 515-7925(F)
My web projection: http://www4.ncsu.edu/~ssbenger

* Always glad to share my ignorance - I've got plenty. *