In some counties, PSTN provider will send the message indicator signal after you hang up the call. This makes MyPBX identify it as a call. However it would show "Unknown" on your phone display.
Firstly and usually you can add a "X." in the Caller ID Number field of inbound route to eliminate the issue.
However if your line doesn't owns a caller ID service, this method doesn't make sense.
Fortunately you can try to utilize the following guide to solve the issue.
Please follow the procedure to figure it out:
1. Verify if you have the get the similar log in the Asterisk CLI mode.
[2015-02-09 13:51:03] NOTICE: chan_dahdi.c:9966 ss_thread: CallerID number: (null), name: (null), flags=44
[2015-02-09 13:51:03] NOTICE: chan_dahdi.c:10145 ss_thread: MWI: Channel 1 no message waiting!
Follow this guide to enter the Asterisk CLI mode: Enter Asterisk CLI mode
Make a test call, answer it and then hang up. Wait for several seconds, when the unknown calls comes out.
Watch the log to check if you can see logs. "Flags=44" is the key mark.
If you can see the mark, you can go ahead.
2. Customize the users.conf
1) Get a brief understanding about how to customize the configuration file in MyPBX with this link: User Defined Configuration Modification
2) Login the SSH and enter command mode by following Enter Command mode.
Input command: vi /persistent/custom-cfg/users_custom.conf.
3) Add the content like the following:
mwimonitor = rpas
mwimonitor = rpas
Note: "trunk_1" means pstn1, you can adjust the content according to how many lines you have.
4) Save this file users_custom.conf, reboot MyPBX to make this modification take effect
4. Test the call again.
Hello everyone. I use S20 series and I don't find : /persistent/custom-cfg/users_custom.conf
I need your help please....