Cisco ESR-24CT1/E1

The Cisco ESR-24CT1/E1 is a network module designed for use with Cisco 4000 Series Integrated Services Routers (ISRs). It provides connectivity for up to 24 T1 or E1 interfaces, allowing for high-speed data and voice transmission over traditional TDM (Time Division Multiplexing) networks. The module supports various protocols and features, including T1/E1 circuit emulation, voice and data integration, and WAN optimization. It is commonly used in enterprise and service provider networks to connect branch offices, remote sites, and service provider access networks.