This port adapter provides one high-speed, full-duplex, synchronous serial E3 interface and integrated data service unit (DSU) functionality. The E3 port adapters can transmit and receive data at E3 rates of up to 34 Mbps and use a 75-ohm coaxial cable available from Cisco to connect to a serial E3 network. These port adapters support the following: 16- and 32-bit cyclic redundancy checks (CRC), high-speed HDLC data, G.751 framing or bypass, HDB3 line coding, ATM-DXI, Frame Relay, HDLC, PPP, and SMDS serial encapsulation, national service bits, E3 MIB (RFC 1407), scrambling and reduced bandwidth, remote and local loopbacks.The PA-E3 port adapter supports the RFC 1407 DS3 Near End Group, including DS3/E3 Configuration Table, DS3/E3 Current Table, DS3/E3 Interval Table, DS3/E3 Total Table.The PA-E3 port adapter also supports the Card Table in the Cisco Chassis MIB and the MIB-2 for each PA-E3 interface. The PA-E3 port adapter does not support the RFC 1407 DS3 Far End Group and DS3/E3 Fractional Group.