Self-synchronizing communication protocols

An approach called self-synchronizing communication protocols (SSPs) is presented for handling synchronization problems in communication protocols. It is found that many synchronization errors are caused by process collision, which arises when two or more processes simultaneously transmit conflicting messages. A synchronization mechanism that allows processes to detect and resolve collisions during operation is proposed. Advantages of this approach are the simplification and standardization of protocol design. The alternative design of two operating protocols, the CCITT X.21 and a session control protocol in the IBM System Network Architecture (SNA), using SSPs is discussed. It is found that all the errors in a previous version of X.21 result directly from process collision. Making the protocol a suitable candidate for the application of SSPs. The design of an abbreviated version of the SNA session-control protocol using SSPs shows the applicability of the method to protocols with more than two processes and the resulting simplification of the design