user has upgraded the u1910 to V200R003C20SPC900 and after upgrade all outgoing calls through the AT0 trunk dropped after 3 second
- confirm that all used AT0 trunk are active and calls are working fine when connecting the AT0 trunk direct to analog phone without connecting the pbx
- review the used dial and busy tone parameters and confirm its ok by comaring with different sites uses AT0 on the same country
- collecting the call logs using ssh during test the same affected call
the root cause why the outgoing call disconnected is the U1910 incorrectly detects the peer signal as a congestion tone( once the U1910 detect a congestion tone , the call will be disconnected )
1- adjust the configuration of the congestion tone of U1910.
3- Choose the congestion tone which are configured on this U1910 site.
Then click automatic detection to adjust the parameter of the congestion tone.