Factory Function - Audio Loopback

Factory Function - Audio Loopback 

The factory function audio loopback test is integrated by default with Grandstream phones. The purpose of this test is to confirm the functionality of the handset, speakerphone, or headset. Both audio in and audio out of your Grandstream device will be assessed.

To conduct an Audio Loopback test from your Grandstream GXP 21XX series follow these steps below:

1. Press the Circle key (located in the center of the directional keys).
   
   
   
   
2. Using the Circle key, select System (shortcut by pressing 7 key).
   
   
   
   
3. Using the Circle key, select Factory Functions.
   
   
   
   
4. Using the Circle key, select Audio Loopback. 
   
   
   
   
5. Once selected, the Audio Loopback test will immediately begin using the speakerphone. By lifting the handset off-hook you will be able to speak into it and hear your voice repeated. This will allow you to test to see if the input or output of your handset, speakerphone, and/or headset are functioning properly. 
   
   
   
   
6. To exit the Audio Loopback test, select the corresponding Softkey located at the bottom left side of the Grandstream display.