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Re: [EFM] OAM loop back / echo server function


I have been designing, building, and supporting very high performance IP 
networks for several years, for both internal and services usages.  The 
characteristic of latency variance caused by the combination of store and 
forward queues and differential packet sizes always degrades the 
performance of applications on networks that have a high utilization.  It 
requires the additional complexity of some form of QOS to compensate for 
that induced latency variance by the IP "stack".  I have yet to see anybody 
make something more complex and less expensive at the same time.

802.3 does not have any store and forward queues.  Most Ethernet data 
switches only have one store and forward queue, at the 802.1 
level.  Ethernet does not need to have complex QOS functions in order to 
support very time and performance critical applications such as broadcast 
quality interactive video conferencing.  Voice over the data network is 
just the beginning of the types of high margin services that might be 
supported over EFM.  The key to all of this is to not make it any more 
complex than it needs to be and it will then be more cost effective for 
service providers to deploy the technology at a profit.

Thank you,
Roy Bynum

At 08:30 AM 9/5/01 -0400, Fletcher E  Kittredge wrote:
>On Tue, 04 Sep 2001 18:32:24 -0500  Roy Bynum wrote:
> > There will need to be some physical layer command functionality in order
> > to  provide management functions that are not data traffic invasive.  That
> > is one of the requirements of the OAM.  If it is not done within the EFM
> > physical layer, then the service will only be "best effort" and not the
> > high margin services that will be required to pay for the infrastructure
> > deployment of EFM.
>The above opinion is that best effort IP is not suitable for high margin
>services.  There are many well-educated, very experienced and
>successful engineers who hold the opposite opinion: that correctly
>configured, best effort IP is the most cost effective solution for
>providing high margin services.  We feel we have a sufficiency of data
>to back up this position (for an incomplete introduction,  start with:
> .)
>I am not asking you to agree with us.  I don't think this is the
>proper forum for the discussion.  I do request that your above
>statement is noted as opinion not fact, and ask that nothing make it
>into the standard which would impose additional cost on those who do
>not agree with your opinion.  That is, if you can add the OAM
>management functionality to 802.3ah with no increase in complexity,
>please do so. Otherwise, it belongs in a different spec.
>In my view, arguments about the necessity of QoS should probably take
>place off line.  However, it is indisputable that the necessity of QoS
>is disputable (sorry!)
>thank you again,
>Fletcher Kittredge
>Great Works Internet
>8 Pomerleau St.
>Biddeford, ME 04005
>Fax: 207-286-2061
>Phone: 207-286-8686 x.134