[156946] in North American Network Operators' Group
Re: /. Terabit Ethernet is Dead, for Now
daemon@ATHENA.MIT.EDU (Mikael Abrahamsson)
Mon Oct 1 06:19:01 2012
Date: Mon, 1 Oct 2012 12:18:32 +0200 (CEST)
From: Mikael Abrahamsson <swmike@swm.pp.se>
To: nanog@nanog.org
In-Reply-To: <90d6f59c19749e33362af6ac82023edf@ninjabadger.net>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Mon, 1 Oct 2012, tom@ninjabadger.net wrote:
> If you can afford Wave Logic 3 interfaces for your Nortel^WCiena 6500's,
> you'll find some pretty impressive things are actually possible,
> including 100G per 100GHz guide over very large distances (think
> Atlantic-large).
The amount of processing power and equipment in the transponder to achieve
this is most likely out of scope for short term practical 400GE/1TBE that
IEEE will put into standard.
So serial lights on/off much faster than 25 Gbaud runs into serious
physical limitations, as some physical effects increase 4-fold when you
on/off blink 2 times as fast. That's why we do not have 100Gbaud 100GE,
but instead 4x25Gbaud.
> Coherence appears to be the secret sauce in pushing the SnR boundaries,
> albeit I'm not going to pretend to even understand the physics involved, I
> was just lucky enough to speak to some people that do. :)
Yes, for long-haul DWDM systems coherent detection is absolutely the way
to go. For short and metro reach at low cost, that is probably going to be
a bit further into the future.
--
Mikael Abrahamsson email: swmike@swm.pp.se
