Application Note: Set SIP Privacy headers when using SIP trunks from multiple operators

Goal

When a SOP is configured to use SIP trunks from multiple providers, it might require different SIP Privacy headers to be set, such as the Privacy header and the P-Asserted-Identity header. This documents aims to explain how this can be realized.

Implementation

Connect to the SMP.

Routes

• If you already have a route going the SIP trunk you can edit it with the values explained below.
• If you don't : create a new one by clicking on the Add button.
  • Set your telephony route.
  • Select your route group.
  • Select the latest version of MapNumber.

Example:

Map Number

On the routes list, look up for the route that you just created and click on MapNumber.

• Manipulate number : strip all digits
• Add prefix : select an avaible callflow root extension (in this example *158)
• Variable : NumberToDial
• Restriction Group : select one of the restriction groups.

Example:

Callflow editor

Add a new call flow by clicking on the Add button.

• Root Extension : Select the root extension that you have set in the MapNumber configuration (*158 in this example).
• First Action : Select the latest version of SetVar.

SetVar

On the callflow list, click on the call flow that you just have created. Edit SetVar action and set the variables

• SipPrivacyHeader
• SipPrivateAssertedIdentityNumber

The value of SipPrivacyHeader will be set to the Privacy header, the value of SipPrivateAssertedIdentityNumber will be set to the P-Asserted-Identity. The values are specified by your SIP provider.

CallInterfaces

Add CallInterfaces >= 1.4 to the next action possible on the callflow.

• Number to dial : ${NumberToDial} as set in the MapNumber configuration.
• Interface 1: Name of your SIP trunk.
• Caller ID policy : As set in Global Parameters.

Example: