Method and system for dequeuing connection requests in a simplex switch

A system and method is provided for dequeuing connection requests in a data communications system comprising a calling subsystem and a called subsystem connected by a serial simplex switch. The connection requests are made by the calling subsystem to the called subsystem by sending a connect request message to the switch and queuing the connect request message in a buffer therein. The switch establishes a connection between the calling subsystem and the called subsystem by thereafter queuing the connect request message in a buffer in the called subsystem. Concurrently, the switch sends a connect request acknowledge message to the calling subsystem while the calling subsystem sends a connect request dequeue message to the switch. To prevent loss of synchronization between the calling subsystem and the switch, the connect request dequeue message received by the switch is interpreted as a disconnect request message and the connect request acknowledge message received by the calling subsystem is interpreted as a connect request dequeue acknowledge message. The connect request dequeue message and the disconnect request message are identically serially encoded, as are the connect request acknowledge message and the connect request dequeue acknowledge message, to enable such interpretation.