Re: QoS for TelePresence/Packet Sequence Preservation?

Hi CCIE League,

I find this question interesting as I know what packet sequence preservation
means but don't know a darn way of achieving it. Simply speaking, Packet
sequence preservation , as the name suggests is to make sure that no packets
arrive out of sequence since the arrival of out of order packets or the time
consumed in re-sequencing them can affect certain applications such as
real-time video. I did try to google a way on how it is configured or
acheived but the closest I could find is to configure per-flow load
balancing rather than per-packet. Here is a link to the pdf which explains
what per-flow ( that's what your link is talking about as well ) packet
sequence preservation is .

http://www.employees.org/~jevans/je-cf_ieee-int-comp_part1.pdf

It might not help much but I hope it does a little bit ..

Ravi

On Tue, Aug 25, 2009 at 12:03 PM, CCIE League <ccieleague_at_ymail.com> wrote:

> ((Sorry my last email had lot of junk - not used to text formats!! - i m
> reapting my query below))
>
> Hello Experts,
>
> Not for CCIE exam... but a general query...
>
> Got following requirements from Cisco to implement TP QoS (PE node)... all
> seems fine.. but what's "Packet sequence preservation" (PSP) with respect to
> QoS.. Could anyone please clarify?
>
> ------- TP QoS Specs---------
> The PE node provides key functionality for effective delivery of
> TelePresence connections The features to be enabled include:
>
> A class of service queue designed to ensure TelePresence traffic is treated
> appropriately across the network Quality of Service features including:
> - Policed high priority queue
> - Assured forwarding queue
> - [[[[[Packet sequence preservation ]]]]]
> - Marking for TelePresence bearer traffic must be CS4
> - Marking for TelePresence signaling traffic must be CS3 or 5
> - Ingress and Egress policers must be enabled on the real time traffic
> that is destined for a strict priority queue.
> - A policer must be added to ensure that the strict-priority traffic does
> not exceed the contracted bandwidth at the egress PE PE router must have
> capability to map several edge classes into a single aggregate backbone
> class.
> ---------------------------------------------------------------------
>
>
> It's also mentioned under SLA attributes as per-flow packet seq
> preservation
> http://211.79.59.247/Course/QoS20071122/slide/Day1-02-EndToEndQoSOverview.pdf
>
>
> Could anyone shed some light on this please... what is it, how it
> configured or verified?
>
> Thanks in advace.
>
> Cheers,
> CCIE League
>
>
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Received on Tue Aug 25 2009 - 15:23:58 ART