Tony Li wrote:
A key observation here is that the point of an optical cross connect is to provide a real circuit, not a virtual one.
Tony - the way i see it, a "real" circuit is something which requires a technican to go on site to connect or disconnect it. Any circuit which can be routed under software control is a virtual circuit. In this case these wavelengths or whatever are no different from CBR flame delay or ATM circuits. Now, if one wants to get really philosophical, it all depends on time frame. A capacity planning software may issue orders to technicans to go and do things -- but it'll take days. If you're ok with that kind of response time, the "real" circuits are also virtual ;) The funny thing is, the change rates in traffic engineering world are pretty close to the human-assisted VC switching's :) --vadim