CLI Procedure for Adjusting E&M Voice Channels

Use the test setup shown in the figure below. Initially, set both Voice Network Analyzers (VNA) to BRDG, TEST and OFF. The PBX station numbers, trunk access code, and network extension numbers in the figure below are fictitious, used here for reference only.

1. Select the first two E&M voice channels within the local unit to be adjusted. Set any additional voice channels to forced On busy condition to insure that the test calls operate only through the channels under test. It is assumed that the signaling format for the E&M voice channel is configured for DC.
2. Place a call from the No.1 telephone to the No.2 telephone. To do that, lift the No.1 telephone off-hook, wait for the dial tone, and dial the tie trunk access code (typically 80). A second dial tone should be heard from voice channel 1.
3. Dial network extension 16. You should hear a third dial tone from the PBX.
4. Dial PBX station 456. The No.2 telephone set will ring.
5. Place the SETUP switch on the No.2 Voice Network Analyzer to TERM. The telephone will stop ringing.
6. Place the SETUP switch on the No.1 Voice Network Analyzer to TONE, and disconnect the No.1 telephone from the Voice Network Analyzer.
7. From the Command Line Interface, display the input level status of E&M voice channel 1. To do that, enter:

CLI> show voice channels entry limb1

Assuming that E&M voice channel 1 is in channel 1 of logical interface module B, you will receive the following typical display:

CLI> show voice channel status table

8. Observe the display on the asynchronous terminal and note the input level for the channel. If the reading is more positive than -4 dBm, apply negative gain (input attenuation) until this reading is above -4 dBm.

Example:

The reading is -1 dBm. The Input Level Gain setting in the associated voice profile is -2 dB.

Add three increments of negative gain by changing the setting to -5 dB.To do that, you must first find the profile ID number associated with that channel, then change the input level setting of that profile.

To find the profile ID number, enter:

CLI> show voice parameters table

You will receive the following typical display for both E&M voice channels:

Note and write down the Profile ID number. In the above example, both channels 1 and 2 are assumed to be in logical interface module b (limb), and both use Profile ID 1.

Next, access the CLI>set voice profile inputLevelGain menu. Use 1 for the Profile integer, then add or subtract gain as necessary by changing the InputLevelGain integer. Finally, update the configuration using the CLI>save configuration command.

After the input level gain adjustment is completed, note and write down the setting used to bring the input level to -4 dBm. You will need it for setting the second E&M channel. Finally, update the configuration using the CLI> save configuration command.

9. Move on to the voice Output Level Attenuation configuration for the E&M channel No. 2 (the channel that is connected to the channel just adjusted).
10. Read the value of the receive level on the No.2 Network Analyzer display. The receive level should be approximately -12 dBm. Set the output attenuation until the receive level display is -12 dBm +2dBm, using the following command:

CLI>set voice profile outputLevel

Use 1 for the Profile integer, then add attenuation if and as necessary by changing the OutputLevelAttenuation integer. After the output level adjustment is completed, note and write down this value. You will need it for setting the output level of the first E&M interface channel. Finally, update the configuration using the CLI>save configuration command.

Perceived voice quality is not significantly affected until the receive level drops below -16 dBm.

11. You have now established the input gain setting on the No.1 channel and the output level attenuation setting on the No.2 channel.

Next, you may either repeat this procedure to adjust the input level gain setting on the No.2 channel, and the output level attenuation setting on the No.1 channel, or you may set the input level and output levels of the remote channel to the settings recorded in this procedure.

End Of Topic