The ADTRAN MX3208 Controller Card is a plug-in unit for the MX3 Chassis that provides eight DSX-1 drops from up to two DS3s. The remaining DS1s may be routed between the DS3s or to optional drop modules in the MX3 Chassis. Two MX3208 Controller Cards are used together to provide a redundant circuit.This product includes: 1189001L1 (1) - A 1RU, 19-inch chassis allows DS1 to be routed between the two DS3 interfaces with access to 14 DS1s at any node. Chassis houses DS3 controller cards and other cards including 4-port router with terminal server; 189002L1 (2) - The DS3 card with 8 DSX-1 ports is a hot-swappable plug-in unit for the 19-inch ADMX chassis. It provides DS1 drop and insert capability for DS3 networks.