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RE: [EFM] Minutes of P2MP Optics conference 22nd Aug 20002

You uncovered that I still have a copperhead mentality or should I say Bell
Shaped Head. But, I am flying the fiber flag now. However, I sometimes can
be observed attending copper subgroup meetings to participate in the latest
vote in linecode battles. 

You answered my request with a GigE link between central office and a remote
VDSL ONU.  I was asking about the use of P2MP interfaces rather than P2P
GigE for Hybrid Fiber/Copper architectures.  With the expected efficiency of
P2MP, could an operator feed 4 VDSL nodes with 200 subs each? Or would point
to point GIgE be needed for each VDSL node? I like conserving my embedded
feeder fiber if I can! I like single fiber P2P and PON for reducing fiber
cost whether making the most use of what fiber is there or planning large
deployments that scale.


> -----Original Message-----
> From: Hugh Barrass [mailto:hbarrass@xxxxxxxxx] 
> Sent: Friday, August 23, 2002 3:52 PM
> To: Mccammon, Kent G.
> Cc: 'gkramer@xxxxxxxxxxx'; Thomas.Murphy@xxxxxxxxxxxx; 
> Subject: Re: [EFM] Minutes of P2MP Optics conference 22nd Aug 20002
> Kent,
> It's great to see you're flying the "hybrid fiber/copper" flag!
> Most video codecs are designed to spit out monotonic streams 
> of (nearly) equal sized frames. These frames will either be 
> at the MTU size or as long as the VSP dares to make them 
> (many will limit the frame size to 1024 bytes for 
> superstitious reasons). The data stream will consist of many 
> (i.e. >20) frames at the maximum size followed by one short frame.
> Note that a gigabit link will be able to carry 200-400 
> streams of unicast or multicast video, so it will take a 
> large number of subscribers to fill the pipe (& therefore 
> stress the efficiency).
> Hugh.
> "Mccammon, Kent G." wrote:
> > Glen,
> > Referring to your comment about frame size distribution from actual 
> > traffic.
> >
> > > 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).
> >
> > Does anyone in the group have a traffic sample from a network 
> > transporting digital video streams to give frame size distribution? 
> > For example, a traffic sample for digital video over fiber 
> to a VDSL 
> > ONU to serve several hundred VDSL lines to a residential gateway.  
> > That scenario may be a good one to look at for traffic on a 
> > residential GigaPON connected to multiple VDSL ONU 
> locations with data 
> > and switched digital video content.
> >