Cisco SM-X-1T3/E3 Enhanced Service Module - expansion module

The Cisco SM-X-1T3/E3 1-port T3/E3 enhanced service module (SM-X) is a software-configurable T3/E3 product for Second Generation Integrated Services Routers (ISR G2) and the Cisco 4451-X integrated services router. This flexible enhanced service module enables you to switch between T3 and E3 applications with a single Cisco IOS command.

The SM-X-1T3/E3 enhanced service module supports a single-port T3 or E3 with an integrated channel service unit (CSU) and a data service unit (DSU). It supports High-Level Data Link Control (HDLC), PPP, and frame relay.