RE: [EFM] Minutes of P2MP Optics conference 22nd Aug 20002
Can the bandwidth for the "guard bands" be quantified?
The frame format for P2MP is already fixed by the PAR.
At 09:43 AM 8/23/2002 -0700, Glen Kramer wrote:
>This is to address action item #2 from the minutes.
>2. Efficiency model based on guard bands and traffic type - P2MP group?
>There are 3 types of overhead (or bandwidth loss):
>1. Cycle overhead. This is overhead used by guard bands (including CDR).
>It is measured as a number of guard bands in one cycle. This number at
>least equal to the number of ONUs, but may be even larger if we grant
>per LLID and there are multiple LLIDs per ONU.
>2. Slot overhead. This overhead arises when granted slot does not take
>into account frame delineation in a buffer. Since frames cannot be
>fragmented, a frame that doesn't fit in the remainder of a slot will be
>deferred to next slot (in next cycle), leaving current slot
>The size of unused slot remainder depends on frame size distribution.
>This distribution for today's traffic is known and there exist formula
>to calculate this unused remainder (for the case when assigned slot size
>has no correlation to the frame sizes).
>Few protocol proposals consider how to eliminate unused slot remainder
>completely, but it looks like it will require changes to the frame
>format. P2MP group is still debating about it.
>3. Frame overhead. That includes IFG and headers. Nothing we can do
> > -----Original Message-----
> > From: firstname.lastname@example.org
> > efm@xxxxxxxxxxxxxxxxxx] On Behalf Of Thomas.Murphy@xxxxxxxxxxxx
> > Sent: Friday, August 23, 2002 1:57 AM
> > To: email@example.com
> > Subject: [EFM] Minutes of P2MP Optics conference 22nd Aug 20002
> > Hello All,
> > First off I apologise for sending this mail to the
> > EFM reflector, however, a number of issues arose which
> > are relevant for other groups.
> > The next phone conference is planned for next Thursday
> > at the old time of 11:00 Eastern
> > Regards
> > Tom