There is no reason to use Sonet equipment any longer other than to recover the cost of purchasing it. You have to be just as reliable as the incumbent and cheaper. There are solutions out there, but they're not proven. At the same time, Lalani admits to the long term inevitability of Ethernet. It's all a matter of when and how fast.
Some vendors claim that reliability and restoration problems are already solved.
There is no reason to use Sonet equipment any longer other than to recover the cost of purchasing it. Shuler is quick to explain, however, that unembellished enterprise-class Ethernet is not going to make it in the carrier space, even switched Ethernet, which eliminates the contention problem. You can't construct rings because of spanning tree problems, and you can't provide synchronous services because there is no way of passing timing information, because you don't have regularly recurring cells or frames. Even with MPLS, which we support, you still have the timing problem. It's a problem we solve by injecting a carrier every 125 microseconds.