Invocation of the Advice of Charge service is performed by the originating node; thus, this feature should be enabled from the service provider or SIP server side. Once AoC is invoked, the originating node receives charging information using supplementary service data structures.
This guide describes types of AoC how to use the Advice of Charge (AoC) service, and some screenshots showing the AoC information received during and at the end of calls.
Two AoC types are available, each type determines AoC information to be returned at a different point in the call:
- AoC during the call (AoC-D): AoC-D provides the user with information about cost of the call during the call. For example, a subtotal of the cost could be sent to the user on an interval basis.
- AoC at the end of the call (AoC-E): AoC-E provides the user side with the total cost of the call at the time the call is ended (or later).
The most popular AoC values are:
- Basic communication details (Call duration, Current call charge, Final call charge …).
- Price per time unit.
- Flat rate.
Users may request to their service providers some supplementary service operations or a user-to-user information transfer which include the following charge rate values:
- Price per time unit and time unit.
- Flat rate (a fixed currency value per event).
- Special charging code.
- Price per volume unit and volume unit.
AoC information should be included in SIP messages respecting XML format. Call originating GXP phones will fetch data received and display it on the LCD screen.
During an active call, service provider or SIP server (with AoC-D service enabled) may send charging information embedded in periodic SIP INFO messages including current consumption or other charging data.
Please refer to the following Wireshark capture showing AoC-D information in SIP INFO message:
At the end of a call, service provider or SIP server (with AoC-E service enabled) may send charging information embedded in a SIP BYE or 200 OK messages including summary of ended call (duration, costs, final charge and price per time).
When the phone originating the call is not the one ending the call, AoC-E information will be included in SIP BYE as shown in the following Wireshark capture:
When the phone originating the call is the one ending the call, AoC-E information will be included in SIP 200 OK message (response to BYE message). Please refer to the following Wireshark capture showing AoC-E information in SIP 200 OK message:
Following screenshots show how AoC-D and AoC-E information are displayed in each one of GXP and GXV models:
Following table shows Grandstream products supporting Advice of Charge feature:
|Model||Supported||Active by default||Firmware|
22.214.171.124 or higher
126.96.36.199 or higher
188.8.131.52 or higher
184.108.40.206 or higher
220.127.116.11 or higher