QOS or more bandwidth

Tue May 29 15:19:05 UTC 2001

On Tue, 29 May 2001, Ukyo Kuonji wrote:

> The problem is, while most vendors support tagging and
> priority queuing, non of the current vendors can support
> true end to end QoS.  Instead, we have taken to calling
> their options CoS.

The elusive "end-to-end QoS" seems to be a network
management issue, motivated primarily by the number of knobs
(and some featuritis) and lack of QoS best-practice (because
there's just not a lot of QoS practice, period).

Simple end-to-end technologies (TOS, DiffServ) are enough to
handle congestion-management QoS strategies (and some
differentiated services), are interoperable across most
vendors, and are supported in most edge- and core-class
devices.

Beyond simple QoS schemes, the complexity mandates an
end-to-end management tool. I suspect the cost/benefit curve
gets pretty flat above a simple QoS strategy, and anything
more complex has diminishing marginal value.

Any studies been done on cost/benefit of QoS, it'd be
interesting to see where the technical/business case is
compelling and where it makes no sense.

Pete.