I got several emails as a response to my previous post and enjoyed them all. One proposed channel I saw and really liked was the mailboat channel .

On a more futuristic note, if the mars explorer were to use WCF, it would probably have the same extremely long latency and reliability issues that the Carrier Pigeon channel has. This brings us to the topic of 'message exchange patterns', or MEPs. The message exchange pattern exposed by all the above channels is a one-way datagram. And in reality, it is hard to think of any low-level communication that is not built on a one-way channel. However, this is not always the appropriate model to use in communication systems.

Two higher-level channel abstractions that WCF exposes are the Request-Reply abstraction, and the DuplexSession abstraction. More of these abstractions in my next post....