Communication system for sending dissimilar types of data across a synchronous network

The communications system for carrying out interconnection of the network of multimedia equipment, a network interface, and a communication port are offered. Multimedia equipment can send streaming and/or non-streaming data through a network. A network corresponds to such a kind of all data, assigns the kind of data to the time slot or frame segment in each frame, and it secures it so that temporal relationship may be maintained with the receiver with which stream data were united with the transmitter. According to one enforcement form, a signal dispatch byte is preferably used for isochrony streaming data always recording the quantity which occupies a frame segment. According to the 2nd enforcement form, the 1st coding violation is used for expressing the beginning of the asynchronous nature arranged in the segment secured for such data or isochrony data. Moreover, since the end of transmission of the isochrony in a segment, an asynchronous message, or data is expressed, the 2nd coding violation in a data stream can be used. According to the 3rd enforcement form, since it means that the isochrony streaming data in the byte position including coding violation does not exist, the coding violation in one or the frame segment of the frame beyond it is used. Therefore, the coding violation can check that it is dotted between an isochrony data message or data transfer, and the specific portion of a frame segment does not contain isochrony data.