Binding the same port number on different interfaces

Hi,

We can use the same port number for two applications based on protocols.(i.e one application is based on TCP and the other application based on UDP).

But i don't know about interfaces, can anyone one help........

   1\) Can we use same port number for different applications on a single interface.

   2\) Can we use same port number for different applications on different  interfaces\(interfaces have separate ip address\).

Consider that same port number can be used on different applications, then won,t it be a problem in receiving the packets.

           Applications using UDP protocol.
          \--------------------------------

1) Application 1 is binded to the port number 1500 and ip address of an interface.(Transfer the packet through the selected interface).

                  2\) Application 2 is binded to the port number 1500 and ip address is 0.0.0.0

Now, inorder to transfer the packet of Application 2 an interface has to be selected based on destination's ip address.
If application 2 want's to transfer packets with different destination ip adresses, then different interfaces will be selected for different interfaces.(so application 2 may transfer packet through any one of the available interface and where as application 1 will transfer through the specific interface).

          --->After receiving  the packet, how should i select the socket of application 1 and application 2.

Problem is both sockets are binded to same port number and interface on which application 2 is transferring the packets are not fixed.