Note 1: Isochronous burst transmission enables communication between data terminal equipment (DTE) and data networks that operate at dissimilar data signaling rates, such as when the information-bearer channel rate is higher than the DTE output data signaling rate.
Note 2: The binary digits are transferred at the information-bearer channel rate. The transfer is interrupted at intervals in order to produce the required average data signaling rate.
Note 3: The interruption is always for an integral number of unit intervals.
Note 4: Isochronous burst transmission has particular application where envelopes are being transferred between data circuit-terminating equipment (DCE) and only the bytes contained within the envelopes are being transferred between the DCE and the DTE. Synonyms burst isochronous (deprecated) , interrupted isochronous transmission.
Source: from Federal Standard 1037C and from MIL-STD-188