Once you've obtained a channel manager from the binding element, you have the first object that is usable for network communication. Although the two kinds of channel managers, channel factories and channel listeners, share many of the same methods, the use of those methods tends to be quite a bit different. I'm going through just the client-side channel factory in the list, but I'll point out some bits of information that differ between channel factories and channel listeners.

To get a minimally working channel factory for a custom channel, you need to think about what you're going to do in five particular methods.

1. The holdover from binding elements to channel managers is GetProperty. The implementation of GetProperty should at a minimum return a response for every interface that you had support for on the binding element. The return value itself should be exactly the same as well, for the values that would have been returned at the moment you created the channel factory. Future changes to the binding element settings should never change the values returned by the channel factory.
2. Open is a hook to let you perform some work prior to making the first service call. This is your chance to do any preconnection work, like looking up credentials, that you want to have costed during startup rather than taking time during a service call. When programming against a service with a client proxy, opening the proxy is an optional step. However, even if the user doesn't open the proxy, your channel factory and channel will get opened prior to the first call taking place.
3. Close is the hook to let you clean up any state left behind that takes time to get rid of, such as open network connections. There is a different meaning for Close between channel factories and channel listeners. Closing a channel factory is supposed to similarly close all of the channels created from that factory. Closing a channel listener doesn't touch the existing channels. Therefore, you're going to have to structure your state differently between the channel factory and channel listener. For the channel listener, you are essentially forced to push more state into the channels so that they can survive the destruction of their channel listener.
4. Abort is a similar idea to Close, but is a part of the ungraceful shutdown process. Rather than nicely cleaning up the state, you are expected to take care of the state problem by blowing it away with abandon. Abort should never do anything with the network or other blocking operations. Just make the channel manager go away as fast as possible.
5. The workhorse and probably the only interesting method in most channel factories is CreateChannel. CreateChannel is what actually stamps out channel instances for use by clients. Channel listeners have several variants on accepting, which is the rough equivalent for the server. Accepting is generally a more complicated process because it is a combination of the user wanting a channel and some external connection arriving.

Next time: Setting the Message Via