Re: proposed charter 5 priority levels

Janet P Gunn <[email protected]> Tue, 26 Sep 2006 09:44:40 -0400
Newsgroups gmane.ietf.ieprep
Message-ID <OFBAA95066.05652C8C-ON852571F5.004A9C8A-852571F5.004B6690@csc.com>




As RFC 4412 makes perfectly clear, the RPH serves a dual role of signalling
priority across an IP network (e.g. from an originating circuit switched
access network to a terminating circuit switched access network) as well as
signalling  priority within the IP network.

For each of the namespaces described in RFC 4412, the number of priority
values (5 in most cases, 6 in one) is driven by the former role, based on
the number of priority values in use, or being considered, in the access
network priority scheme.

The issue of how many priority levels to differentiate WITHIN the IP
network is an issue currently being addressed by vendors and providers.

Janet



Curtis Villamizar <[email protected]> wrote on 09/26/2006 01:21:39 AM:


>
> As long as the number of priority/preemption classes remains too open
> ended, the mapping onto DSCP and Diffserv-TE remains uncertain.  For
> example, there has to be a strong technical justification for five
> priority classes, not just "because ITU specified five" before there
> is much of a chance for a set of new DSCP values to be assigned as
> anything other than experimental.
>
>