>the ATM media convergence sub-layer, by design, fits the sizing of SONET >tributaries like a glove. This was no coincidence;
Is there anything intrinsic to DWDM which would prevent the ATM forum from building a transmission convergence sub-layer to it? ASND has really used crafty marketure to imply that their switches can interface directly to DWDM. As near as I can tell, they are interfacing to a SONET box which also has DWDM capabilities. I am not sure why that is special but perhaps I don't understand their PRs.
The prevailing wisdom by many smart people is indeed, that the "ongoing improvements in class-of-service (CoS) and QoS characterizations in IP", will obsolete ATM. The argument, as you well know is that the ATM cell tax is inefficient. It's ironic that many people arguing that, also believe cheap bandwidth, made possible by photonic switching/DWDM, obviates the need for traffic engineering. The argument is of course, that you just built bigger pipes. The efficiency of that strategy, as opposed to an ATM "cell tax", is questionable in my view.
Finally, the efforts of the DiffServ/RSVP working groups may eventually provide acceptable QoS to IP. But I sometimes wonder at what cost? I don't pretend to be close to those working groups but as near as I can tell, they are just moving the "complicated" signalling mechanisms of ATM up the protocol stack. When do you (or anyone) expect their efforts to be deployed(and functioning)in a ILEC, CLEC, or ISP network? |
