MDO-15 Rackmount PDH utilizes rack configuration to increase spatial utilization ratio and improves the performance of network management system. 16E1, 8E1 and dual 4E1 slots can be inserted hybridly, offering users a more convenient, effective and quicker way to establish and manage the whole networks in the point-to-point networking. Each slot has the same functions like 16E1/ 8E1 /4E1 terminal transceiver(desk-top). Therefore, they can be mutually exchanged and used to build up point-to-point and point-to-multipoint networks with small transportation volume, large net cell number, high reliable and perfect auxiliary functions, such as military, mobile, telecom, electric power, road and airline point-to-point and point-to-multipoint private wire networks.