Callback applications

Callback lets a caller avoid paying for the incoming leg: the switch calls them back and the outgoing calls are billed to their account at your rates. ANI Callback reacts to a call to an access number: it hangs up, calls the caller back and runs another application, usually a calling card. Two-way callback is requested by your own system: the switch calls party A, and when A answers, calls party B and connects them.

How it works

ANI Callback:

1. The caller dials the callback access number. The application recognises the caller’s number as a trusted number of an account, or falls back to Default Account Username.
2. It rejects the call with Hangup SIP Response Code, or lets it ring for Ringback Time, so the caller is not charged.
3. After Delay Before Callback it calls the caller back, retrying every Backoff Interval up to Max # Of Callback Attempts times.
4. When the caller answers, it runs the IVR Application set in its options, for example a calling card, as the caller’s account.

Two-way callback:

1. A callback request is created through the XML-RPC API, a CLD translation rule ani_2way_<number> on a connection, or a record in the switch’s callback request queue.
2. The switch calls the requesting number with the account’s identity.
3. When it answers, the application calls the destination number and connects the two calls. Both legs are billed to the account.

Set it up

ANI Callback:

1. Create the application to run after the callback, for example a Calling Card application.
2. In DIDs & IVR Apps → IVR Applications click Add New, enter Name and select Type ANI Callback.
3. Click Save, open Advanced Parameters and add IVR Application with the application from step 1.
4. Assign the callback access number’s DID to the ANI Callback application.
5. Register the callers’ numbers as trusted numbers of their accounts, or set Default Account Username for callers without one.

Two-way callback from the panel: an account user requests a callback on Services → Callback of their portal. From your own system use the callback methods of the API. To request it from a number, add a connection to the IVR service with the CLD Translation Rule s/.*/ani_2way_12345/ to call the caller back and connect them to 12345.

Options

ANI Callback options; two-way callback uses the same callback service.

Option	Default	Meaning
IVR Application		Application run after the caller answers the callback
Default Account Username		Account charged for callers without a trusted number
Force Default Account	false	Always use the default account as owner of the callback leg
Enable Anonymous Accounting	true	With false the default account is not charged for the callback leg
Disable CLI Authentication	false	Ignore trusted numbers; use with Default Account Username
Force CLI Authentication	false	Reject callers whose number is not a trusted number
Minimum Balance		Below this balance the default account is used instead of the caller’s
Delay Before Callback	5	Seconds before the first callback attempt
Backoff Interval	10	Seconds between callback attempts
Max # Of Callback Attempts	3	Attempts before the request is given up
Hangup SIP Response Code		SIP code used to reject the initial call
Ringback Time	0	Seconds to indicate ringing before rejecting
Ringback Type	indicate	indicate sends ringing, earlymedia plays it as media
Fixed CLI		Number presented to the caller on the callback leg
SIP Proxy For Callback Calls		Host and port the callback calls are sent to
Scan Interval	5	Seconds between checks of the callback request queue
Timeout	300	Interval in seconds for polling the internal queue
The Reason For Diversion	unconditional	Reason in the Diversion header

Note

A callback costs two outgoing calls. Price both legs in the account’s service plan, and keep Max # Of Callback Attempts low: every unanswered attempt to a mobile network may be charged by your vendor.

Related pages

• IVR applications
• Calling Card application
• Accounts (trusted numbers and services)