AVPops (AVP-operations) module implements a set of script functions which allow access and manipulation of user AVPs (preferences). AVP means attribute-value-pair and it could be seen as a variable which can have integer or string ID and integer or string value. In OpenSER, an AVP is linked to SIP request or SIP transaction, if OpenSER is in stateful mode. The AVP is automatically deallocated when the processing of the SIP request ends.

AVPs introduces in OpenSER many new opportunities for implementing services and preferences per user or domain. With AVPops module they are usable directly from configuration script, allowing the administrators to customize the VoIP service in a more flexible way. Offering capabilities to load dynamically AVPs from databases, many situations that required to restart OpenSER due to configuration changes can be avoided.

The AVPops module exports functions for interfacing DB resources (loading/storing/removing AVPs from database), functions for swapping information between AVPs and SIP messages, functions for testing/checking the value of an AVP.