Designs for communication softwares

I'm about to implement some custom communication protocols for a
distributed system. Anyone got pointers to good designs, design patterns etc that I should not miss before embarking on this

Note that, It's important that these patterns will be reausable and abstract in that way i can use it for more applications.

Waiting for ideas....

.NET Development15

I'm not clear what the question is. Are you asking for wire protocol designs (ie. header layout, etc) or for advice on software patterns when building a network communication layer in a multi-tier application