> For the complete documentation index, see [llms.txt](https://help.sipgate.de/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.sipgate.de/trunking/en/wie-setze-ich-bei-sipgate-trunking-die-absenderrufnummer.md). # How do I set the caller ID in sipgate trunking? If you want to transmit your caller ID number, you must configure your system so that the desired phone number in the **E.164 format** (international format, without leading zeros or plus sign) as **P-Preferred-Identity** header of the INVITE is passed: ``` P-Preferred-Identity: ``` If your system does not support this, the number can alternatively be transmitted in quotation marks as **display name of the FROM header** in the same **E.164 format** be transmitted: ``` FROM: "49211123456789" ``` Incorrect formats that prevent transmission of the desired outgoing caller ID number include, for example: * leading plus: +49211123456789 * Missing country code: 211123456789 * 00 in the country code: 0049211123456789 * Leading zero in the area code: 490211123456789 * Spaces: 49 211 123456789 ## Hide caller ID If you want to suppress the caller ID completely, enter in the INVITE header **privacy:id** in: ``` FROM: "49211123456789" Privacy: id ``` ## Caller ID display for call forwarding You can also signal that a call was forwarded. Please use the header **DIVERSION** and transmit the number again in the **E.164 format**: ``` Diversion: <49211123456789@sipconnect.sipgate.de> ``` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://help.sipgate.de/trunking/en/wie-setze-ich-bei-sipgate-trunking-die-absenderrufnummer.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.