according to this phenomenon, need our channel partner to do the test as below:
1. do the intra-office calling(remove AT0 effect)，test ok.
2. remove U1930, directly use phone to connect to AT0 to make incoming and outgoing calls, test ok.
3.U1930 connection to AT0 with IP phone 7910, no matter the incoming call or outgoing calls,nearly after 2 minutes, the caller and callee are automatically hang up,before we meet the issue like this: 7910 under PBX makes a outgoing call to mobile phone, sometims can get through, sometimes can not. after upgrade 7910 version to SPC700, the issue is resolved. so for this site issue, we also upgrade 7910 to SPC700 and test, issue can not be resolved, the result is as follows:
4.Further communication and understanding with channel partner:U1930 does not have this problem, in the SPC600 version of the scene, after upgrading to SPC800, the channel partner makes a outgoing or incoming call , if two parties long time don't talk, after 2 minutes the phone will automatically hang up. But when they continuously talk once the calling is get through, after long time test, the two sides do not hang up.
5.I doubt this is a new version SPC800 of U1930 for the AT0 connection opening silence detection by default. Login to the U1930 command line,do the following command:
show at0 silence detection parameter
SilenceDetEnable=1 means open,SilenceDetEnable=0 means close.
check that the silence detection is open.
do the command to close the silence detection:
config at0 silence detection switch off
test again, if two parties long time don't talk, calling will not be hang up.