Intercom Auto-Answer capability with Aastra 480i IP Phones..

This refers to FreePBX 2.2.0, Asterisk 1.2.14 and Aastra 480i firmware 1.4.1.1077.
FreePBX auto-generates extensions_additional.conf with the [ext-intercom] context containing a workable hands-free intercom section.
The problem is that the stock [ext-intercom] context won't trigger the auto-answer-alert splash tone on Aastra 480i phones using firmware 1.4.1.1077. That firmware requires a special SIP header to activate the splash tone.
To make it work, you have to REPLACE line 7:
exten => _*80.,n,Set(__ALERT_INFO=Ring Answer)
WITH:
exten => _*80.,n,Set(__SIPADDHEADER=Alert-Info: \;info=alert-autoanswer)
Unfortunately, every time that you use FreePBX to maintain extensions, it overwrites the changes.
I would like to know where in the FreePBX code this context is generated. I might be able to modify my copy of FreePBX, if I could just find the right module and the code.
Thanks in advance for any suggestions!



Intercom Auto-Answer capability with Aastra 480i IP Phones..
Can't you put the functionality and special line into extensions_custom.conf which FreePBX does not generate or modify and not even use the FreePBX intercom feature?
Intercom Auto-Answer capability with Aastra 480i IP Phones..
Thanks for the response.
I hadn't thought of that and so I gave it a try this afternoon. Unfortunately, your suggestion doesn't work. I can copy the ext-intercom context to extensions_custom.conf (which is included), but as soon as I disable the Intercom feature, ICOM calls fail.
Enabling Intercom changes more than just extensions_additional.conf and the other changes won't work in the extensions_custom.conf file. Nice try though :)
So, I would like to just find out what code generates the ext-intercom context in extensions_additional.conf. With that, I might be able to easily fix the syntax.
Thanks again!