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Re: [RPRWG] RAH: Re: Minutes of Rate Ad Hoc meeting




Yiming, 

speaking as a technical expert,

while I understand your desire to have LP packets dropped, be aware
that 802 has never had a MAC that drops packets from the medium 
except due to a CRC errors. 

From a compliance testing perspective, the issue of packet drops
would make it difficult (if not impossible) to provide a test
that proved compliance if packet drops were allowed. Remember,
if you can't test for compliance, it is not a standard.

I believe that proper use of reserved BW will remove any need to 
drop packets. I look forward to seeing the simulation results
that show problems as a part of the RAH.


mike


> Yiming Yao wrote:
> 
> Hans,
> 
> The current draft of the RPR standard tries to achieve several objectives: high link utilization,
> guaranteed minimum jitter for reserved HP traffic, no packet loss on the ring, etc, and these
> objectives are conflicting to each other sometimes. One customer may want to disallow any LP
> packet drop on the ring even this means high jitter for the HP traffic; another may want to
> guarantee minimum jitter to HP traffic (carrying TDM) at risk of occasionally dropping some LP
> packets.
> 
> My suggestion is that RPR provide a choice for the customer to make his/her decision in conflict
> resolution.
> 
> I didn't assume the operator wants to adjust the total load/throughput. Maybe this can be done
> more easily if the above choice is provided.
> 
> Regards,
> 
> Yiming
> 
>      -----Original Message-----
>      From: hans-j.reumerman@xxxxxxxxxxx [mailto:hans-j.reumerman@xxxxxxxxxxx]
>      Sent: Friday, March 15, 2002 1:35 AM
>      To: stds-802-17@xxxxxxxx
>      Subject: [RPRWG] RAH: Re: Minutes of Rate Ad Hoc meeting
> 
>      > Yiming Yao: allow customer to choose between loss, jitter, and utilization
> 
>      Is the underlying assumption that the operator of the ring (=customer?) wants to
>      adjust the total load/throughput?  Would this be for loadbalancing purposes?
> 
>      regards,
>      Hans
> 
>      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>      Hans-Jürgen Reumerman
>       Hans-J.Reumerman@xxxxxxxxxxx
>      Digital Communications & networking                  pww.pfa.research.philips.com/dc/
>      Philips Research Laboratories                               Phone: +49 241 6003 629
>      Weisshausstr.2, 52066 Aachen, Germany           Fax:   +49 241 6003 519
>      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-- 
Michael Takefman              tak@xxxxxxxxx
Manager of Engineering,       Cisco Systems
Chair IEEE 802.17 Stds WG
2000 Innovation Dr, Ottawa, Canada, K2K 3E8
voice: 613-254-3399       fax: 613-254-4867