NDS management can be broken up and delegated way down the tree. It's only central if you decide to make it so. Thus they act like domains synchronizing with each other. This is a consequence of design decision, not an advantage. In fact, quite the opposite is true.
Cable modems are strictly asymmetric, typically highly so.
On the other hand, most xDSL services are symmetric or nearly so, except at the highest data rates. As for cable modems, Marks correctly points out that most cable operators have taken an asymmetric approach, delivering about 2 Mbps downstream and as little as 100 kilobits per second upstream. Then subscribe to the IAW E-Mail Alert. Openwave Be a part of the communications revolution. 810, the high-tech dream machine.