- Use the test setup shown in the figure below. Initially, set both Voice Network Analyzers to BRDG, TEST, and OFF.
- Lift the No.1 telephone set off-hook. Dial extension 456. The No.2 telephone set will ring.
- Place the SETUP switch on the No.2 Voice Network Analyzer to TERM. The telephone will stop ringing.
- Place the SETUP switch on the No.1 Voice Network Analyzer to TONE, and disconnect the No.1 telephone from the Voice Network Analyzer.
- Display the Voice Status, as follows:
CLI> show voice channel status entry
- Observe the display on the asynchronous terminal and note the input level of the channel. If the reading is more positive than -4 dBm, apply attenuation (negative gain) in the amount that this reading is above -4 dBm.
Normally, this will require the Input Level Gain to be set between -2 and -4 dBm depending on cabling loss. (Note: If the Input Gain is currently set for 0 and the Input Level is below -10 dBm, then the FXS channel should be evaluated for a problem.)
To adjust the input level for the No.1 FXS channel, adjust the Input Level Gain for the appropriate voice channel as in step 9 of PBX Tie Trunk Application Adjustments. After the input level gain adjustment is completed, record the setting used to bring the input level to -4 dBm.You will need it to set the other FXS channels. Save the new setting using the save configuration command.
- Move on to the voice Output Level Attenuation configuration for FXS channel No. 2.
- Read the value of the receive level on the No.2 Voice Network Analyzer display. The receive level should be approximately -12 dBm. Set the output attenuation until the receive level display is -12 dBm +2 dBm, as in step 10 of the PBX Tie Trunk Application procedure. Record the setting, and save, using the save configuration command.
- You have now established the input level gain setting on the No.1 channel, and the output level attenuation setting on the No.2 channel. Next, adjust the input level gain setting on the No.2 channel, and the output level attenuation setting on the No.1 channel. To do that, set the input level of the second channel to the value recorded in step 7, and set the output level of channel 1 to the value recorded in step 9. As an alternative, repeat this procedure in the opposite direction, using the second voice channel as the input end and the first voice channel as the output end.
- Now that both channels are adjusted, test the voice quality. To do that, place both Voice Network Analyzer SETUP switches to BRDG, take one telephone off-hook and lift the other telephone off-hook when it rings. Talk to verify that there are no echoes. If there are echoes, increase the output level attenuation setting on the distant channel.
- Restore both channels to system controlled Busy.
- Remove any and all test equipment, such as Voice Network Analyzers and telephone sets, and restore the system to normal service.
End Of Topic
