P-Charge Header

The P-Charge Info Header in the SIP URI indicates the number which will be billed for a particular call. The P-Charge Info header is much like the Charge Number parameter in ISUP. The IMG 2020 supports interworking the P-Charge Info Header from both SIP to SS7/ISUP and the SIP INVITE message on incoming leg to SIP INVITE message on outgoing leg. Once the P-Charge Header has been inter-worked to the SS7/ISUP leg, it can be used to generate or interact with other entities to create billing records. See below for more information.

Call Flow Diagram

SIP to SS7

SIP to SIP

P-Charge Info Trace Example (SIP to SS7):

Example:

P-Charge Info: <sip:6425555555@10.10.10.10>;npi=ISDN;noa=2

noa = The Nature of Address in the SIP URI will be inserted to SS7/ISUP signaling without conversion.

npi = The Numbering Plan Indicator will be converted from SIP URI to SS7/ISUP as shown in table below.

Callers Number = 6425555555 - The callers number will be inter-worked into SS7/ISUP as shown in table below.

Configuration

To configure the IMG 2020 to interwork the SIP URI P-Charge Info Header, the SIP Profile object must be configured to enable the interworking to occur. The procedure below will explain how to configure the SIP Profile object and link it to a SIP channel group.

Initial Configuration

Before configuring, the IMG 2020 must have an initial configuration created on it. Follow the Basic Configurations procedure before proceeding. 

Create SIP Signaling Gateway Profile (SGP)

Create a SIP Profile object. Under the SIP Profile object, the SIP Headers object is created. The P-Charge is enabled/disabled there. Follow procedure below

• Create a SIP Profile. Right click on the Dialogic object and select New Profiles. The Profiles object is a parent or container object and no configuration is needed here.

• Right click on the Profiles object and select New SIP Profile. The first profile that gets created is a Default SIP Profile and cannot be modified. Disregard this profile.

• Right click on the Profiles object just created again and select New SIP Profile. Either enter a Name into the name field that identifies this profile or accept the default entry. Refer to the SIP Profile - SGP topic for more information on configuring each of the individual fields.

• Right click on the SIP Profile object just created and select New SIP Headers. Enable the SIP P-Charge feature by selecting Enabled from the drop down menu in the P-Charge-Info field. Refer to the topic for more information on configuring each of the individual fields in this object.

Create SIP signaling stack

• Right click on the IMG 2020 physical node and select New Signaling.  The Signaling object is a parent or container object and no configuration is needed here. Refer to the Signaling topic for more information on this object.

• Right click on the Signaling object created and select New SIP. In the IP Address field, select from the drop down menu which IP address will be used for SIP signaling. Refer to IMG 1010 - SIP Signaling Object topic for more information.

Create SIP Channel Groups

• Right click on the Dialogic object and select New Routing Configuration. The Routing Configuration object is a parent or container object and no configuration is needed here. Refer to the IMG 1010 - Configuring Routing topic for more information.

• Right click on Routing Configuration and select New Channel Groups. The Channel Groups object is a container object also and no configuration is needed. Refer to the Channel Groups topic for more information.

• Right click on Channel Groups object and select New Channel Group. Either enter a name that identifies this channel group or accept the default entry. In this example the Channel Group was labeled SIP_PCharge_ChGrp.

• Select SIP from the drop down menu of the Signaling Type field. Refer to the Channel Group topic for more information on configuring this object.

Create an External Gateway

The SIP Channel group needs to communicate with an external SIP entity. Create an external network element and then an external gateway that the SIP channel group will transmit messages to. Follow procedure below to communicate with a remote gateway.

• Right click on the Dialogic object and select New External Network Elements. The External Network Elements object is a parent or container object and no configuration is needed here. Refer to External Network Elements topic for more information.

• Right click on External Network Elements and select New External Gateways. The External Gateways object is a parent or container object also and no configuration is needed here. Refer to External Gateways for more information.

• Right click on External Gateways and select New External Gateway. Enter a name that identifies the gateway being configured. In this example the gateway was labeled SIP_MWI_GW

For more information refer to the External Gateway topic.

Insert SIP External Network Element into SIP Channel Group

• Right Click on the SIP Channel group created and select New IP Network Element. Within the IP Network Element field, select from drop down menu, the gateway created. See screen capture below.

• Click on the Channel Groups object again. The Channel Groups object will have a yellow exclamation point in place of the icon indicating the configuration has not been sent to the IMG 2020. Click on the Download Resource Tables button and the new configuration will be sent to the IMG 2020.

• At this point, the P-Charge header has been configured into a SIP Channel Group.

Additional Information

• Interworking of P-Charge Info Header and Charge number is available for SIP to SIP, SIP to ISUP, and ISUP to SIP. SIP to SIP and SIP to ISUP are described above. ISUP to SIP interworking is configured in the SS7 - Destination - ISUP Group - Parameter Filter topic.

• The P-Charge Info Header and Charge number are supported in ANSI only.

• P-Charge INFO Header, by default, is set to enabled.

• When P-Charge Info Header functionality and Diversion Header functionality are both present in the SIP INVITE, the P-Charge-Info Header shall have precedence. Below is a table displaying the different scenarios that would result from enabling/disabling the Diversion Header and P-Charge Info Header in a SIP to SIP call.