/. Terabit Ethernet is Dead, for Now
tom at ninjabadger.net
Sun Sep 30 22:49:16 UTC 2012
On 30/09/12 20:05, Jimmy Hess wrote:
> On 9/29/12, Masataka Ohta<mohta at necom830.hpcl.titech.ac.jp> wrote:
>> >Jared Mauch wrote:
>> >The problem is that physical layer of 100GE (with 10*10G) and
>> >10*10GE are identical (if same plug and cable are used both for
>> >100GE and 10*10GE).
> Interesting. Well, I would say if there are no technical
> improvements that will significantly improve performance over the best
> possible carrier Ethernet bonding implementation and no cost savings
> at the physical layer over picking the higher data rate physical
> layer standard,_after_ considering the increased hardware costs
> due to newly manufactured components for a standard that is just
> E.g. If no fewer transceivers and fewer strands of fiber required,
> or shorter wavelength required, so it doesn't enable you to achieve
> greater throughput over the same amount of light spectrum on your
> cabling, and therefore lower cost at sufficient density, then: in
> that case, there will probably be fairly little point in having the
> higher rate standard exist in the first place, as long as the
> bonding mechanisms available are good for the previous standard.
When you consider 100GBASE-LR4 (with its 4x25G form factor) there is
some efficiency to be gained. ADVA & others now support the running of
each channel on their DWDM muxes at ~28G, to suit carrying 100GBASE-LR4
over four of your existing waves. CFPs with 4xSFP+ tunable optics in the
front are out there for this reason.
Once you get your head (and wallet) around that, there becomes a case
for running each of your waves at 2.5x the rate they're employed at now.
The remaining question is then to decide if that's cheaper than running
Still a hard one to justify though, I agree.
I've recently seen a presentation from EPF** (by Juniper) that was
*very* interesting in the >100G race, from a technical perspective. Well
worth hunting that one down if you can, as it details a lot about optic
composition in future standards, optic densities/backplanes, etc.
** I couldn't justify going, but the nerd porn is hard to turn down. :)
More information about the NANOG