How quickly will enterprises see 40 G Ethernet service for long-haul data communications? Pretty soon, according to the vendors supplying the leading carriers, but perhaps not as quickly as some might think, according to those familiar with the technology.
Even though there is still no official 40 GbE standard, it will undoubtedly require next-generation Optical Carrier (OC) equipment, namely OC-768. Most solutions deliver 40 G service using Time Division Multiplexing, which delivers data at four times the baud rate of 10 G solutions but delivers four times less light to the receiver, meaning it will have only a quarter of the reach.
Dense Wavelength Division Multiplexing (DWDM) offers better performance, but there is still the fact that most long-haul services are likely to run into non-40 G infrastructure at some point. Some people are talking about bundling four 10 G streams together and then sorting it all out at the router, but it's not clear whether such a plan would be cost effective.
At the very least, we have to give the carriers kudos for foresight. With a 40 GbE standard still at least two years away, they just might have these issues worked out in that time.