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RE: [EFM] EFM Requirements > Talking about voice transport...

> Talking about voice transport...

Voice in p2p:

If we mess with the PHY (unlikely) then carrying voice becomes easy (can
have its own channel effectively, outside of the 1GE).

If we don't mess with the PHY (probable) then carrying voice requires some
QoS mechanism, either within the EFM spec., or above it. If above it, then
the upper layer would need to control _all_ packets, not just the time
critical packets, else we are back in the non-deterministic realm. If it's
above EFM then it's an application / implementation specific issue.

Roy - I am not talking about voice over the internet here. We are talking
about voice over well controlled private packet networks (owned and
controlled by service providers), so they are reasonably quantifiable :-).

Bob B.

> -----Original Message-----
> From:
> []On Behalf Of Carlos
> Ribeiro
> Sent: 23 August 2001 12:44
> To: mattsquire@xxxxxxx; Harry Hvostov
> Cc: Lough, Andy; Stds-802-3-Efm (E-mail); carlosal@xxxxxxxxxxxxxxxxxx
> Subject: Re: [EFM] EFM Requirements
> Talking about voice transport...
> At 20:09 20/08/01 -0400, Matt Squire wrote:
> >So what.  At the Ethernet level a packet has priority.  Someone has
> >classified this packet as important.  Therefore, the network should do
> >what it can to not discard the packet and to give it a relatively low
> >latency.  The packet can be carrying voice, video, or my mother's secret
> >lasagna recipe - I don't care.  I've been told its important - the
> >application is irrelevant.
> I must make sure that we are talking about the same Ethernet
> here. Ethernet
> by itself has no priority mechanism. A bunch of proprietary schemes were
> created, and some standard work was done, but I'm not aware of any widely
> deployed, complete, standards-based, solution for prioritization on the
> Ethernet level. I'm happy to be proved wrong, though, as it would be
> something really nice to have.
> Now, if EFM will have the mechanisms to tag packets as important
> (non-discardable, low latency, and so on), then you're right. You are
> simply mapping IP QoS over Ethernet. But even then, the standard
> group has
> some work to do, to make sure that the prioritization mapping is done the
> right way.
> >The point is that the Ethernet layer has no additional work to do to
> >carry voice.  Therefore the requirements for transporting voice need not
> >be singled out - there are none.
> As I said, this is not granted - at least as far as I know. You have
> pointed out that there are several ways to carry voice; in my
> opinion, some
> of them will need specific provisions in the standard. If we can map
> everything to standard features of the Ethernet, then you're
> right, and we
> have nothing to worry.
> Carlos Ribeiro
> CTBC Telecom