RC7216, produced by Raycom corporation,is an ASIC used to transmit Ethernet frames using 4-E1 channels.Ethernet to 4-E1 bridge can be easily made using RC7216 with a few peripheral circuits.Through 4-E1,it transmits 10M/100M Ethernet MAC frames point-to-point and tolerates a little interval in 4 E1 channels.The structure,principle and application of bridge with RC7216 are introduced