Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [EFM] RE: [EFM-P2MP] 10G EPONs (it was MPCP: Report message)


> Assuming we agree with you with the amount of bandwidth that is needed
> in the downstream. For this 2.5 Gbps are good enough. In that case why
> we need to pay for expansive optic in the upstream. Home users will
> still need the same small amount of bandwidth. 622 will be enough. I
> guess asymmetric rates are making a lot of sense for FTTH application.
> B.t.w - The FSAN ILEC's are very consistent with their asymmetric rates
> requirements.

Assymetric rates are an artifact from the common perception that users want 
high speed content fed upon them. It's also related to the fear that MSOs 
will dominate the access network, so ILECs need a way to counteract and to 
provide CATV-equivalent services. However, this is not a consensus, even 
inside the biggest ILECS.

There has been considerable debate whether assymetric rates are the best way 
to deploy a broadband network. I have actual experience on this, because I'm 
responsible for the supporting IP backbone at CTBC Telecom; there we are 
seeing a growing trend towards symetric usage, even from otherwise normal 
websurfers. It was very common to have ratios such as 4:1 
upstream/downstream; now, it's getting close to 2.5:1. What is more 
interesting - the difference is smaller with DSL and cable modem users, 
around 2:1 (or even less!).

Some lessons we've learnt:

- Content is not king. People want to communicate. WAP was a flop, but SMS is 
a winner. The screen size and the keyboard are the same, but one is 'central 
content', the other one is 'one-to-one communication'.
- People like to share content. Legal problems aside, that's the fact.
- Hosting content is not hard. In fact, it will only become increasingly 

Another reason *not* to use lower speed optics on the upstream for EFM P2MP: 
even if the optics are the same, the system is already assymetric. Using 
lower speed optics at the upstream will only make things worse. 

Carlos Ribeiro
CTBC Telecom

Carlos Ribeiro
CTBC Telecom