A communication system processes blocks of input data that include control words and a packet of information words are received. The packet has a start preceded by ones of the control words and an end followed by others of the control words. When the block consists exclusively of information words, a one bit block header having a first sense is appended to the block to form a frame. When the block does not consist exclusively of information words, the block is condensed to accommodate a TYPE word, the TYPE word is generated and inserted into the block and a one bit block header is appended to the block to form the frame. When the block does not consist exclusively of information words the one bit block header has a second sense, opposite to the first sense. Use of a one bit block header reduces overhead. Forward error correction is also utilized.