Presence_CallInfo Module

The module does not currently implement any authorization rules. It assumes that publish requests are only issued by a third-party application and subscribe requests only by subscriber to call-info and line-seize events. Authorization can thus be easily done by OpenSIPS configuration file before calling handle_publish() and handle_subscribe() functions.

To get better understanding on how the module works please take a look at the follwing figure:

   caller       proxy &   callee        watcher        publisher
alice@example  presence  bob@example  watcher@example
                 server                       
     |             |           |           |              |
     |             |<-----SUBSCRIBE bob----|              |
     |             |------200 OK---------->|              |
     |             |------NOTIFY---------->|              |
     |             |<-----200 OK-----------|              |
     |             |           |           |              |
     |--INV bob--->|           |           |              |
     |             |--INV bob->|           |              |
     |             |<-100------|           |              |
     |             |<-----PUBLISH(alerting)---------------|
     |             |------200 OK------------------------->|
     |             |------NOTIFY---------->|              |
     |             |<-----200 OK-----------|              |
     |             |           |           |              |
     |             |<-180 ring-|           |              |
     |<--180 ring--|           |           |              |
     |             |           |           |              |
     |             |           |           |              |
     |             |<-200 OK---|           |              |
     |<--200 OK----|           |           |              |
     |             |<-----PUBLISH(active)-----------------|
     |             |------200 OK------------------------->|
     |             |------NOTIFY---------->|              |
     |             |<-----200 OK-----------|              |
     |             |           |           |              |

			

In this mode, the module requires the "dialog" module to be loaded into OpenSIPS. All the publishing will be automatically done (the modules will exchange data directly via C API).

From presence perspective, the OpenSIPS script must be configured to handle the SUBSCRIBE requests only (there is no need for PUBLISH handling as there is no SIP publishing in this mode). So be sure to use the "handle_subscribe()" function (from presence module) in the script.

To trigger the internal publishing (from the dialog module) for a certain call, use the "sca_set_calling_line()" or "sca_set_called_line()" functions from the script when handling a new call. These functions will do all the work (creating dialog, setting the internal publishing, etc) - you just need to use them and eventually specify the name of the line (if other then the one from the SIP INVITE) - see the below documentation.

LIMITATIONS : in this mode, the module does not really check if the line exists or not (like defined) - it blindly trust the traffic; also there is no check on how many indexes are for each line. Such information (lines and indexes) are not provisioned into the module, but the module will dynamically accept and handle any line and index based on the SIP traffic.

The following modules must be loaded before this module:

None.

Enables or disables call_info event timeout notifications.

Default value is “1” (enabled).

...
modparam("presence_callinfo", "call_info_timeout_notification", 0)
...
			

Enables or disables line_seize event timeout notifications.

Default value is “0” (disabled).

...
modparam("presence_callinfo", "line_seize_timeout_notification", 1)
...
			

Disables the internal publishing of the "call-info" events (generated by the dialog module). The publishing is expected to be done via SIP PUBLISH from a third-party. See the wroking mode described in the beginning of this document.

Default value is “0” (not disabled).

...
modparam("presence_callinfo", "disable_dialog_support_for_sca", 1)
...
			

Allows you to controll the size of the internal hash table used for storing the information about the lines and indexes (in the internal publishing mode).

The value must be a power of 2. You may consider increasing the value if using a large set of lines (>1000).

Default value is “64”.

...
modparam("presence_callinfo", "line_hash_size", 128)
...
			

The function (to be used only in internal publishing mode) is setting for the current new call (initinal INVITE) the outbound line - the line used for calling out.

If no parameter is provided, the name of the line is taken from the SIP FROM header of the INVITE. You can override that by providing the name of the line as a string parameter - be careful as the value must be a SIP URI !

This function can be used from REQUEST_ROUTE.

...
	if (is_method("INVITE") and !has_totag()) {
		sca_set_calling_line();
	}
...

The function (to be used only in internal publishing mode) is setting for the current new call (initinal INVITE) the inbound line - the line the call was received on.

If no parameter is provided, the name of the line is taken from the SIP RURI of the INVITE. You can override that by providing the name of the line as a string parameter - be careful as the value must be a SIP URI ! Variables are accepted.

This function can be used from REQUEST_ROUTE.

...
	if (is_method("INVITE") and !has_totag()) {
		sca_set_called_line();
	}
...