TX 4000 PCI SS7 Network Interface Board Installation Manual | Establishing network connections |
Testing in loopback mode
You can connect the board in loopback mode to test the digital trunk application without connecting to the telephone network. The following illustration shows the loopback configuration that connects trunk 1 and trunk 2 with crossover cable on a TX 4000 board:
Crossover cable 
Trunks 1 and 3
Trunks 2 and 4
11
22
44
55
W i r i ng diagram of crossover cable
The crossover cable connects the transmit signals from one trunk to the receive signals on another trunk by connecting the pins as shown.
If your board configuration uses two optional trunk adapter cables to access trunks 3 and 4, you can connect the adapter cables in loopback mode. Use the crossover cable to connect the transmit signals on one of the adapter cables to the receive signals on the second adapter cable as shown in the following illustration:
Dual T1/E1 120 ohm
adapter cables
T r u n k s 1 and 3
Trunks 2 and 4
Ethernet 1
Ethernet 2
Shielded RJ - 4 5 c ables
TX 4000 board
Dialogic Corporation | 33 |