Subject: Re: Unused bandwidth policy

From: Lixia Zhang <[email-masked]>
Date: Sat, 21 Dec 1996 07:07:48 PST

I know this msg has been two weeks old, but didnt see a reply, so better late
than never :-)

> Hello:
> 
> When a bandwidth is reserved at a router/switch for a session, it is not
> clear from the specs if the reserved bandwidth should be treated exclusive
> for the session. From the definition of controlled-load service, it 
> appears that the scheduler could use any unused reserved bandwidth for other
> flows. And the guaranteed service appears to claim exclusive access to the
> reserved bandwidth.

yes that's roughly the case.
- just to make it clear, this is an admission control issue not the setup
  protocol 
- so put it in precise terms, it is not the scheduler (which does nothing but
  shuffling pkts around), but the admission control which decides whether
  further requests can be handled based on the current reservation/load state.

> I feel that irrespective of the type of service, it should be up to the 
> users to request the BW as either exclusive or sharable when not used. 
> This could be a RSVP policy info that will be used by the schedulers 
> along the path. The result is two-fold. It could increase the network
> utilization and I could be charged less for making my reservation
> non-exclusive.

Given a user can already choose between "exclusive" and "shared" reservation
by choosing different service types, I wonder why why you consider it
desirable to have another way for doing the same thing.

Lixia

---

From: Masataka Ohta <[email-masked]>
Date: Sun, 22 Dec 96 17:46:07 JST

Lixia;

> desirable to have another way for doing the same thing.

Perhaps, some kind of people who are working on reservation-only
networking just do not know that there is best effort traffic
which can consume unused resources exclusively reserved by
someone else.

						Masataka Ohta