Activating P-Asserted Identity (RFC 3325) for SIP Gateway Trunks (kb4028)

The information in this article applies to:

  • SwyxWare v6.20

[ Summary | Information ]


Since Quickfix 4 for SwyxWare 6.20 it is now possible to use the "P-Asserted Identitiy Header" for SIP-Gatewaytrunks.

This article describes the configuration of Swyxxware via the Windows registry to activate the header.


For SIP-calls it is useful to distinguish between asserted and trusted calling line identities (CLIP).

As reference for this, a wellknown function from the ISDN has been used. In ISDN you can use the "User-Provided-" and the "Network-Provided-ID".
Analogue to this method there are the SIP headers "P-Preferred-" und "P-Assereted-Identity" regarding to RFC 3325.

SwyxWare makes use of the P-Preferred Header per default for internal and external SIP connections. Quickfix 4 for v6.20 provides a possibility to make use of the P-Asserted header additionally to the P-Preferred Header. This might be a compatibility advantage when using third-party SIP-gateway products with SwyxWare.


Activating the header is been realized by adding a special key into the Windows registry. Please proceed as follows:
Open the Registry-Editor of your SwyxWare Server. (Start -> Run -> RegEdit)

Navigate to this registry-tree:

Create a new DWORD named:  "SIPUsePAssertedIdentityHeaderForGW"
(right mouseclick -> New...)

The value "1" activates the header, the value "0" deactivates it.

Afterwards close the RegistryEditor and all Swyx-regarding Applications.
Restart the SwyxConfigDataStore Service.

Thats it.


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