IPmux-1/1E Installation and Operation Manual Chapter 4 Troubleshooting and Diagnostics
Diagnostic Tests 4-25
4.4 Diagnostic Tests Maintenance capabilities include external and internal loopbacks.
E1/T1
External Loop
IPmux-1 can be set to an external loop to test the connection between the E1/T1
port and the PBX (refer to IPmux-1 E1/T1 Configuration in Appendix E). In this
mode, data coming from the PBX is both looped back to the PBX and transmitted
forward to the IP network (see Figure 4-5).
This mode can also be achieved by a T1 FDL line loopback command.
PBX IPmux-1
Figure 4-5. IPmux-1 External Loop
Internal Loop
The E1/T1 module can be set to an internal loop to test the connection between
the E1/T1 port and the IP network (refer to IPmux-1 E1/T1 Configuration in
Appendix E). In this mode (E1/T1 only), data coming from the IP network is both
looped back to the IP network and an AIS pattern is transmitted forward to the
PBX connected to the E1/T1 port (see Figure 4-6).
PBX AIS IPmux-1
Figure 4-6. IPmux-1 Internal Loop
To run a loopback test:
• Press the <Spacebar> on your keyboard to toggle between the values:
Internal/External /Disable.
− Internal: Data received from the IP network side is looped back to the
network transmit line. An unframed all ‘1’ code (AIS) is transmitted in the
E1 Tx path toward the PBX. Incoming data from the PBX is ignored.
− External: Data received from the PBX at the receive E1 line is looped back
to the E1 Tx path (toward the same PBX), and continues its way to the
IP network. Data coming from the IP network is ignored.
− Disable: No loopback. Regular operation.
Default value: Disable
Main Menu
↓
2. Configuration
↓
2. E1/T1
Configuration
↓
3. Loopback
State