Re: /. Terabit Ethernet is Dead, for Now

[Masataka Ohta <mohta () necom830 hpcl titech ac jp>]

joel jaeggli 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
> > newer.
> There is a real-estate problem. 10 sfp+ connectors takes a lot more 
> space than one qsfp+. mtp/mpo connectors and the associated trunk ribbon 
> cables are a lot more compact than the equivalent 10Gbe footprint 
> terminated as LC.

That's why I wrote:

> > > (if same plug and cable are used both for
> > > 100GE and 10*10GE).

As is mentioned in 40G thread, 24 Port 40GE interface module
of Extreme BD X8 can be used as 96 port 10GE.

> When you add cwdm as 40Gb/s lr4 does the fiber count
> drops by a lot.

That's also possible with 4*10GE and 4*10GE is a lot more
flexible to enable 3*10GE failure mode trivially and allows
for very large skew.

                                                        Masataka Ohta