Thanks for the explanation!

Usually ports are the equivalent of simultaneous connnections.
DIDs aren't usually tied to a specific port.
Whether outgoing calls take up a port depends on the provider.

I've been somewhat puzzled by the terminology I see on wholesale / enterprise VoIP providers' web pages. What exactly do they mean when they talk about a "port"? E.g. "$30.00 Per Port Unlimited Inbound" - is that something like a "maximum number of simultaneous channels I can use"? And would a DID be tied to a particular port or could I receive an inbound call on any port? Does an outgoing call also take up a port?

Thanks

heby