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

Re: [802.3BA] Discussion on 40G for => 10 km SMF

Hi Mikael,
I don't think anybody is suggesting that we make a decision that we will
NEVER develop a serial interface. There were plenty of 10GbE interfaces
developed after the initial standard. The colored interfaces you are
describing are not even in the standard, but they appear in the market.

The architecture we have chosen supports a variety of lane counts, and
if serial becomes the most cost effective or broadly applicable
interface in the future, no doubt it will be developed. All people are
saying is that based on cost and time to market, 40G serial is not the
right solution to develop now for the first version of the standard. We
don't normally decide what direction to follow for a 2010 product based
on what we speculate someone might invent in 2013.

-----Original Message-----
From: Mikael Abrahamsson [mailto:swmike@xxxxxxxxx] 
Sent: Friday, August 08, 2008 2:15 PM
To: Trowbridge, Stephen J (Steve)
Cc: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: RE: [802.3BA] Discussion on 40G for => 10 km SMF

On Fri, 8 Aug 2008, Trowbridge, Stephen J (Steve) wrote:

> The serial technology being proposed does not extend to colored 
> interfaces in the same way we saw at 1G and 10G. In the first place, 
> it is 1310nm and for DWDM you would need 1550nm. At 1550nm, you 
> couldn't

What about the ~1300 nm CWDM bands then? I realise the external CWDM mux
will impair a lot on the optical budget, but let's say someone in 2013
comes up with a cost effective solution to increase the link budget to
12-15dB without increasing the dispersion tolerances, this would still
enable to have two ~3dB/each CWDM muxes to run a CWDM system with
multiple 40GE serial waves point to point.

Not having the future possibility to have colored 40GE serial over
single mode will limit the future lifespan of 40GE in the metro space.

This might be ok, but it should be realised that this is the case.

Mikael Abrahamsson    email: swmike@xxxxxxxxx