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RE: [EFM] EFM Requirements

At 08:59 20/08/01 +0100, Bob Barrett wrote:
>I am not convinced that the raw fiber plant requirement for EPON is any
>different to that for p2p in the real world. In dense areas there is logic
>in co-locating splitters and fanning out the tail circuits. The only
>difference is passive or active equipment at the 'hub'. Both topologies look
>like physical stars. Note that a lot of real-world SONET / SDH rings also
>look like physical stars too.
>Can carriers comment on this please?


I went into 'lurking mode' for the past few days, mainly because we're 
trying to finish our requirements document. I have some preliminar comments 
that can help you answer your question:

1. We're working on both models (PON and P2P) to understand the issues. As 
far as we could see, the physical network structure can be built exactly 
the same way. A physical star topology supports either a branch-and-tree 
for PONs or a star for P2P; actually it's not very hard to design rings in 
the core network using the same basic design. The only change is the 
distribution hub, which may be either a passive splitter (PON) or a active 
switch (P2P).

2. As for the active equipments, it's not as big an issue as many people 
believe. In an HFC network, you have lots of active equipment (optical 
nodes, amplifiers, and so on); and in many countries, the phone network is 
also designed around small active cabinets (think DLCs) to serve a few 
hundred customers in a very short distance. This kind of deployment is very 
common in Brazil, and it has some clear advantages when compared to the 
'big CO' approach. It depends on so many economical factors that it is very 
hard to come up with a single answer for all the situations.

As for our requirements document, we have a draft, but we're still working 
on it. I believe that it should be possible to send it to the list later 
this week.

Carlos Ribeiro
CTBC Telecom