Abstract: Received Ethernet MII packets are converted to T1/E1 HDSL frames and received T1/E1 HDSL frames are converted into Ethernet MII packets. When Ethernet MII format 4 bit data packets are received they are converted into 8 bit data packets, each 8 bit data packet having an associated signal bit. For T1, a series of twenty-one 8 bit data packets and associated signal bit are combined with three pass bits into a 192 bit T1 HDSL frame. The series of twenty-one multiple 8 bit packets and associated signal bit with three pass bits are transmitted in HDSL format.When T1 HDSL frames having a series of twenty-one 9 bit packets, each 9 bit packet including 8 data bits with an associated signal bit, and three pass bits, are received, the series of twenty-one 9 bit packets and three pass bits are converted into twenty-one groups of 9 bit packets, each 9 bit packet including an 8 bit data packet with an associated signal bit.