Asterisk and FreePBX Caller Initiated Blind Transfers
If you place a call and perform a blind transfer Asterisk will continue dialplan execution with a result of ANSWER. This causes an issue with FreePBX as it thinks dialing on the trunk failed. The transfer will go through, but you receive the all circuits are busy message.
The first time I reported this issue to FreePBX I didn’t get far as they has tested with an Asterisk 1.4 release that didn’t exhibit issue. After reporting the issue with Asterisk somebody mentioned that this started with Asterisk versions after 1.4.21.
My solution was to add lines to the FreePBX generated dialplan to deal with the ANSWER status and hangup the call accordingly. FreePBX acknowledged the issue and has patched their upcoming 2.7 release. I back ported the patch for the 2.6 release.
You can patch your FreePBX 2.6 with the following
cd /var/www/html/admin/modules/core wget http://www.excaliburtech.net/wp-content/uploads/2010/02/freepbx-18.104.22.168-core-functions.patch patch < freepbx-22.214.171.124-core-functions.patch
After the patch is applied open the FreePBX WebGUI, save a page, and click Apply Configuration Changes so the dialplan will be rebuilt to include the patch.