How Long Will 40 Gbps, 100 Gbps Networks Last?

The problem with networks is that they do not last as long as they used to, which means they need to be upgraded more frequently, which also means the ability to raise capital to upgrade the networks is a bigger issue than it once was.

Qwest CTO Pieter Poll, for example, notes that Qwest's bandwidth growth now is 45 percent growth compounded annually, or nearly doubling every two years or so. That in itself is not the big problem, though. The issue is that consumers driving most of that new consumption do not expect to pay more for that consumption increase.

"From my perspective, the industry really needs to focus on tracking down cost per bit at the same rate, otherwise you'll have an equation that's just not going to compute," says Poll. Whether on the capital investment or operating cost fronts, adjustments will have to be made, one concludes.

Still, raw bandwidth increases are not insignificant. "If you look at 2008 for us it was unprecedented in terms of the work we did in the backbone," says John Donovan, AT&T CTO. "The capacity we carried in 2008, five years out, will be a rounding error.

Donovan notes that AT&T's 2 Gbps backbone lasted 7 years, the10 Gbps backbone lasted five years, while the 40 gigabit will last three years.

By historical example, one wonders whether 100-Gbps networks might last as little as two years before requring upgrades.

Donovan suggests carriers will have to rethink how they design networks, how routing is done and how content bits get moved around. One suspects there might be more use of regional or local caches, to avoid having so many bits traverse the entire backbone network.