Re: [EFM] OAM developing Geoff's observation.
On Tue, 18 Sep 2001 07:09:28 -0700 "Geoff Thompson" wrote:
> Fletcher Kittredge wrote:
> >It may be that there is no way to build QoS without inserting it into EFM.
> (1) I don't think that this is true and (2) QoS is out of scope for the
> current EFM project. We do not have carte blanche for meddling with the MAC
> and there is currently no mechanism for handling multiple cues in the MAC
> data stream. Further, it is my belief that (at least for the fiber) that
> EFM is sufficiently over provisioned (in the physical sense, not the
> revenue sense) that EFM will not be a portion of the problem. QoS has value
> only where limited bandwidth causes delay. This is unlikely to be true in
> the EFM portion of a larger system.
Just so we are clear: I completely agree with you. The "may be" in my
statement was to stress that I recognize I might be wrong.
> >However, before adding complicated QoS mechanisms I would like to see
> >significant proof that it is necessary and at least two working prototypes
> >of the mechanism; prototypes which can be easily reproduced.
> >For an IP connection, QoS on one part of a TCP/IP link does not add much
> >value. QoS must be end-to-end to be effective.
> Again, not true. You don't need QoS at the ends if the ends have greater
> bandwidth than the middle.
If a customer is paying me, the local Service Provider (SP), for a
Quality of Service (QoS) link which they are then using to access the
public Internet, that customer could very well complain if the middle
(Internet cloud) doesn't have sufficient bandwidth to keep their local
link full to the QoS defined limits. The point I was trying to make
is that QoS is not of much value if the bandwidth in the middle is not
always more than the bandwidth at the ends. Realistically, all a SP
can guarantee is the bandwidth under the SP's control.