Changdexun DT848 program-controlled telephone exchange 4 in 48 out 8 tow 64 56 40 32 Road 24 port 16 inside extension Hotel Hotel Hotel Group School Internal Network Computer Management
4 into 16 A- computer debugging 4 into the 24 A- computer debugging 4 into 32 A- computer debugging 4 into 40 A- computer debugging 4 into 48 out-computer debugging 4 into 56 A