Asterisk Advanced Retry-Dial and Callback funtionality

One of the biggest drawbacks should a newcomer to an Asterisk PBX find, migrating from legacy analog one is the callback behaviour.

Current developments simulate that callback by placing the callback reversely, starting at the callee phone, and ending at the caller one. This behaviour is inverse to what the user has been using for a long time, and in the short term can produce multiple problems.

User got used to pressing one button to activate the service, thus "capturing" the line, so when the called party hangs, a call is placed between them. For example, on the popular Spanish IBERCOM PBX, this behabiour is known as "retrollamada" and it is obtained when user press *6.

In order to address this, we need a script/code that would follow this approach:

1. Calling party, after calling busy destination, listens to a hearing pointing the possibily to activate the callback by pressing 6.

2. When called party hangs, our script gets an event, and searches through the database, checking if there is a callback service activated.

3. If affirmative and being under the callback expiry time, the script then checks if the parties are available. Should any of them be busy, the callback is postponed.

4. If either of them are idle, then the callback is placed with a caller id as follows:

Callback from ext1. to ext2.

where ext1 is the calling party and ext2 is the called one.

A custom code has been developed at Asterisk Arena to get the behaviour described above. Detailed description of the service, forums and code, can be obtained here

More info at and directly here


EuropeSIP Communication SL
tel: +34-91-6719179
fax: +34-91-6695578

Tierra de Barros 2
28820 Coslada, Madrid

Created by: agorosti, Last modification: Fri 04 of Dec, 2009 (04:34 UTC) by admin
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