On 9/30/12 12:05 PM, Jimmy Hess 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
On 9/29/12, Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp> wrote: 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. When you add cwdm as 40Gb/s lr4 does the fiber count drops by a lot. 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.
Just keep bonding together more and more data links at basic units of 10GE, until the required throughput capacity has been achieved.
It's not as if a newer 1 Tbit standard, will make the bits you send get read at the other end faster than the speed of light. Newer standard does not necessarily mean more reliable, technically better, or more efficient, so it is prudent to consider what is actually achieved that would benefit networks considered to be potential candidates for implementation of the new standard, before actually making it a standard...
-- -JH