Intercom to single extension feature in Asterisk?

I was wondering if there is any easy, standard way to get intercom working in Asterisk. Specifically, intercom to a single extension. It is known by different names. On the phone end it is usually called “autoanswer”. From what I gather, some phones can do this and some can’t but I can’t find a listing or any instructions on how to configure Asterisk.

I know that some phones like the Grandstream GXP2000 have a configurable feature called autoanswer but all that does is automatically answer ALL incoming calls in speakerphone mode after 1 ring. I only want it to answer this way when instructed to by Asterisk. Say *+number+local ext.

This is a VERY common feature in a lot of cheap phone systems and I know a LOT of small businesses would want to use this.

Auto-answer is not part of the SIP specification (and thus nothing Asterisk can do will help), so you’re at the mercy of your phone vendor. If you don’t like the way your phone supports it, you’ll have to find a different manufacturer or beg your current one to make it more usable in a future firmware version.

At least one person on the wiki’s reporting you can set up auto-answer on a per-line basis on the GXP2000, but I can’t comment (and neither does the GXP2000 user guide).

Snom, Cisco, and Polycom SIP phones make it relatively easy to selectively auto-answer calls.

The wiki has sample configurations for both Cisco and Polycom phones that can readily be adapted. The administrator’s guide for any phones you’re using is also a good first stop to learn more about setting up intercom functionality.

[quote=“colinm”]Auto-answer is not part of the SIP specification (and thus nothing Asterisk can do will help), so you’re at the mercy of your phone vendor. If you don’t like the way your phone supports it, you’ll have to find a different manufacturer or beg your current one to make it more usable in a future firmware version.

At least one person on the wiki’s reporting you can set up auto-answer on a per-line basis on the GXP2000, but I can’t comment (and neither does the GXP2000 user guide).

Snom, Cisco, and Polycom SIP phones make it relatively easy to selectively auto-answer calls.

The wiki has sample configurations for both Cisco and Polycom phones that can readily be adapted. The administrator’s guide for any phones you’re using is also a good first stop to learn more about setting up intercom functionality.[/quote]

Actually, after thinking about it a bit more, I suppose the GXP2000 will work ok for this. The phone has 4 configurable virtual lines with individual settings for various things. One of the settings in Autoanswer. It is either on or off so I would need to set one virtual line in the phone as a dedicated intercom extension that ALWAYS autoanswers in speakerphone mode when that extension is dialed. It’s a lot simpler than the hacks I see posted on the Asterisk wiki for the Cisco and Polycom phones.

I can even give that dedicated intercom extension a unique ring tone. I have a GXP2000 and can confirm this works. The phone rings once and then answers in speakerphone mode when the “autoanswer” feature is enabled. :smiley: