This requires you to modify the 3CX databases. While I have done this several times without issue, please be aware that you take full responsibility for your own PBX and you use this info at your own risk. You should make sure to have a good backup on hand. As well, it is likely 3CX would not support these changes and either will I.
OK, here we go....
- Download pgadmin III to use for modifying the database. http://www.pgadmin.org/download/
- Install pgadmin on your 3CX box, the defaults should be fine
- Launch pgadmin and go to 'File->Add Server'
- For 'Name' and 'Host' enter '127.0.0.1'
- For 'Port' enter '5480'
- For 'username' enter 'phonesystem'
- For 'password' we need to perform the following....open your ini file located at c:\program files\3cx phonesystem\bin\3cxphonesystem.ini. Do a Find and look for the string 'dbPassword'. You should find a long alphanumeric string with hyphens. Copy the alphanumeric string and paste into 'password' in pgadmin
- Make sure the 'connect now' option is ticked
- Hit OK.
You are now connected to your 3CX database with full admin rights. At this point, you can completely mung it up.
Now, in pgAdmin....
- Navigate to 'databases->phonesystem->schemas->public->tables'
- Expand tables
- Right click the 'parameter' table and select 'view data->view ALL rows'
- Scroll to the bottom of the table
- We are going to create a new row by typing values in the row marked with '*'
- In column 1 enter 'ALLOWUSEBUSYOPTFORGROUP'
- In column 2 enter 'allow group busy'
- In column 3 enter '0' (thats a zero not an O)
- In column 4 enter '1'
- At this point, the last column has nothing in it
- Click in another field elsewhere in the table (in other words, click off this new row). this commits the row
- Now, click the refresh button at the top of the window. This will autopopulate the last column with the proper next seq num.
- Exit pgadmin
Now, go back to 3CX and restart all services. Once everything comes back up your old 'allowUseBusyOptForGroup' should be working again.