Change SIP Header

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How to adapt the SIP Header from pascom 19.03. onwards?

PJSIP only allows SIP headers to be manipulated in so-called predial handlers. So the dialplan apps created earlier will no longer work!

Overview

Sometimes it is necessary to adapt SIP Headers. Examples: different ringtones depending on the caller, CLIP no screening settings etc. Below you will find Examples of the types of SIP headers that can be adapted for some scenarios.

Via the Trunk Options

The simplest method is to use the options field in the Trunk Account Settings. A pascom specific syntax makes it easier to set headers. Sip Headers set in the options always automatically beat the values set by the trunk (e.g. CLIP=auto).

Example: Clip no screening.

header/P-Asserted-Identity=<sip:09916666666@provider.des.kundens>

As of pascom 19.03. the options field can be used flexibly with variables. A more complex example:

header/P-Asserted-Identity=<sip:{{{048pee_username}}}@{{{048pee_domain}}}>


Variables are evaluated very late in the dialplan. So you can also e.g. put the dialed number or values from labels in a header ($(EXTEN)etc.).

Via a Outbound Script

Of course, as you know it so far, you can use an outbound script to manipulate SIP headers

Example: Set/overwrite a header

Set(HASH(__SIPHEADERS,P-mein-header)=mein-wert)

Example: Remove a header

Set(HASH(__SIPHEADERS,Alert-info)=remove)

For Endpoints

For Endpoints you still have to use a script or actions. The syntax is identical to the outbound script.

Example: Set/overwrite a header

Set(HASH(__SIPHEADERS,Alert-info)=<http://www.notused.de>\;info=alert-group\;x-line-id=0)

Example: Remove a header

Set(HASH(__SIPHEADERS,Alert-info)=remove)

Updated on 19 Feb 2020