The ADTRAN DSU IV ESP (data service unit with embedded SNMP) provides a reliable, high-speed data connection for customer data terminal equipment (DTE) through digital data service (DDS) lines. The DSU IV ESP has an embedded SNMP (simple network management protocol) agent that provides complete SNMP access to the unit through an integral SLIP or PPP async port. The DSU IV ESP's unique, modular approach provides optional 10BaseT Ethernet access for SNMP. Optional ESP DBU cards are available to provide automatic or manual dial backup for the dedicated circuit.