Communicate between WCF applications

Hi, I need to implement two applications. Each one of these applications should be able to connect to the other one and send and receive messages. How do I do that?

This is what I want to do : 1. create application1 on port1
                                     2. create application2 on port2
                                     3. in application1 connect to application2 on port 2
                                     4. in application2 connect to application1 on port 1

I've created two seperate wcf service applications and two client applications. I know how to connect a client application to the service application, but I don't know how to connect from one service to another.

I'm a begginer in WCF, does anyone have a better idea how to implement this?

Thanks.