Modified byte insertion/deletion for HDLC in ISDN

The authors describe a modification of the HDLC protocol to eliminate bit insertion/deletion and convert it into a byte-oriented protocol. Physical layer framing in the integrated-services digital network (ISDN) basic rate and primary rate adapters provide byte/octet-aligned data transmission. Conventional serial bit stream protocols can take advantage of this aspect of the ISDN standard to simplify the hardware necessary to implement the protocols. The modified version provides the same function as zero bit insertion/deletion in HDLC in a more efficient manner. Specifically, a technique is suggested which does byte insertion instead of bit insertion to insure data transparency. It is concluded that, in view of changing data communications standards and high-speed transmission medium, the byte-insertion technique should provide significant throughput enhancement for modified HDLC data links in ISDN