It is not the latter. Incoming and outgoing ports are separate.

When setting up an INCOMING connection, you bind to a specific port to
listen on, waiting for someone to connect / send something to you. Others
then send their connect requests to that port at your IP address.

When initiating an OUTGOING connection, you specify which port to connect to
at the other (remote) end. You cannot specify which port to use as your
outgoing port.

Regards.

"Peter Eisenman" <psallach@landsend.com> wrote in message
news:436dfc5f$0$21941$9b4e6d93@newsread2.arcor-online.net...
> Assume we look an a certain port say, port number 1234.
>
> Are there TWO different ports 1234 - one for the outgoing direction and
> one for the incoming?
> Or is there only one port which can be used only in one direction at a
> certain time: either
> as incoming or outgoing?
>
> If the ladder would be true then an already established incoming
> connection on port 1234 would block
> any outgoing connection on the same port.
>
> Peter