Call Policy

There exists multiple ways to constrain calls performed through the Wazo platform.

Call duration

A common need is to constrain the maximum duration of calls.

Calls consume resources on a system, and are expected to eventually conclude and free those resources. A call that is never hung up will continue consuming resources indefinitely, which limits the capacity of the system to support more calls.

Calls that remain connected indefinitely can be the result of technical issues, such as the system thinking both ends of the call are still connected when they are not. They can also occur if both ends are actually connected on the call indefinitely, such as a user agent(softphone or hardware phone device) connected to the call being left unattended .

Multiple settings can be used to avoid such scenarios and control the maximum duration of calls.

The available options can depend on the type of user lines being used.

SIP endpoints

A user line or a trunk using the SIP protocol is associated with a SIP endpoint.

SIP endpoints support a number of configuration options that can affect call duration.

Those options are supported by way of the Asterisk pjsip driver endpoints configuration.

SIP endpoint options can be configured in two ways:

1. through SIP templates, which can be applied to all or a subset of SIP endpoints in a tenant; each tenant has a global SIP template which represent common options which can apply to all SIP endpoints. Other templates can specify options for a specific subset of SIP endpoints. See SIP templates documentation for information on how to query and configure SIP templates.

2. directly through a SIP endpoint's individual configuration; individual endpoint configuration can be changed through the /api/confd/1.1/endpoints/sip/{sip_uuid} REST API endpoint. See API reference for details.

SIP endpoint options relevant for controlling call duration include

• rtp_timeout: this option sets a timeout(in seconds) when no RTP traffic is flowing to this endpoint(meaning no audio or video path is functionally established between this endpoint and its peer) while off hold
• rtp_hold_timeout: this option sets a timeout(in seconds) when no RTP traffic is flowing to this endpoint(meaning no audio or video path is functionally established between this endpoint and its peer) while on-hold
• set_var: TIMEOUT(absolute)=<seconds>: here the set_var option of SIP endpoints can be used to set an Asterisk channel variable TIMEOUT(absolute), which limits the absolute maximum duration of a call with that SIP endpoint; this affects any call, no matter its particular state at the expiration of the timeout(i.e. whether there is any kind of activity or not on the call)

Note: since wazo platform release 24.08, a set_var: TIMEOUT(absolute)=36000 option is included in global SIP templates, thus limiting all calls using SIP endpoints to 10 hours by default. This timeout value can be changed by changing this option in the endpoint options of the global SIP template of a tenant.