HWIC-1DSU-56K4-RF - Cisco 1-Port 4-Wire 56/64Kb/s CSU/DSU WAN Interface Card

Cisco 1-Port 4-Wire 56-/64-kbps CSU/DSU WAN Interface Card - DSU/CSU - HWIC - 64 Kbps - refurbished - for Cisco 1905, 1921, 1921 4-pair, 1921 ADSL2+, 1921 T1, 1941, 2901, 2911, 2921, 2951 The Cisco 1-Port 4-Wire 56-/64-kbps CSU/DSU WAN Interface Card (HWIC-1DSU-56K4) performs the channel service unit/data service unit (CSU/DSU) functions for both digital data service (DDS) and 4-wire switched 56-kbps (56K) data networks. In addition, it provides an all-rate synchronous interface to any dedicated DDS point-to-point or multipoint network compatible.