The HDLC MIB for the Unisphere Networks enterprise. This MIB provides a means for configuring HDLC interfaces on top of various types of interfaces, such as packet over SONET (POS) and high speed serial interfaces (HSSI). Management objects are provided to query for an available interface index, and to create/delete interfaces of this type. Creating/deleting this interface type using this MIB has the side effect of creating/deleting corresponding entries in the IF-MIB.ifTable, the IF-MIB.ifXTable, and the Unisphere-Data-IF-MIB.usdIfTable.