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RE: [MIP-QOS] RE: MIP-QOS MIP QoS Mailing List is Active Now
Title: RE: MIP-QOS MIP QoS Mailing List is Active Now
Gwendal,
Glenn,
I
agree with what you said here, i will just make one comment about using FEC
and unequal protection. believe this is
definately a good idea. But maybe it should not be required for all
"important" paquets. I think this implies some channel estimation techniques
to be used (isn't it out of the scope of this work ?)
[Morrow, Glenn
]
It seems to me
that some signaling has to be able to communicate to the access
networks that this function is to be done. The signaling to do this can be
triggered via interactions with Layer 5 (SIP, H.323, etc..) which would imply
some special access specific and security association with the access routing
equipment or the parameters can be included as part of some end to end
reservation signaling. Including the media type in the end to end reservation
signaling allows a pure host to host communication with QoS and without the need
for a proxy at all or at least not associated with the visited access
network.If an access link layer does not support the function,
it simply ignores the parameter. So with these points in mind, I think it should
be in the scope of NSIS.
Moreover, we have" to be careful about not having the same problem
as with IEEE802.11 where all the signaling is carried at a minimal rate for a
better protection. In that specific case, that degrades performance when
higher rates for the goodput are to be used. My point here is that FEC is
probably more flexible and achieves better performance but it should be only
used when the channel is bad.
[Morrow, Glenn
]
I believe that
some more work will eventually be done to the 802.11 MAC to
provide CoS similar to the ethernet work. I believe an SBM will work for
the bandwidth problem. I suspect that doing unequal protection on
802.11 would be overkill. If you examine the business aspects from a monetary
perspective of 802.11 and cellular, you might begin to see that including a
media type in the reservation signaling is more justified than
not.
Another point about wireless channels (here i am
thinking especially about wireless LANs) : some people say that the
channel is often good (and no protcetion is required) and sometimes very bad
(and no data can be transmitted). What do you think about this statement (to
what extent is it true or false) ? Then, if it is really true, FEC will
not improve performance.
[Morrow, Glenn
]
If the
cost of wireless LAN spectrum was significant and the primary
traffic type was expected to be voice, I would consider it. Neither is true,
though, so I wouldn't ever consider it. I do think some CoS work could be done
to 802.11 analogous to the .p work on ethernet which could significantly improve
it. I wouldn't use unequal protection schemes though.
Thanks
Gwendal