MESSAGE EXCHANGE METHOD

摘要

Described is an architecture and protocol for exchanging messsages within a distributive data processing system. Instead of transmitting a frame with a beginning flag field (SDEL) followed by an address field as is the usual case, the SDEL field and address field collapsed and merged into a single field. The field includes a control bit whose setting determines whether the field is the beginning of a frame or otherwise. A second control bit within the single field is used to identify the type of message being transmitted and the response that a recipient station is permitted to return to a control unit issuing the message. The protocol is well suited for framing messages in the well known SDLC communications format. In this format it allows the detection of delimiters without resorting to bit stuffing.