Telephone numbering plan

The service uses the E.164 numbering plan. A number is made up of the country code (CC), the nation destination code (NDC) and the subscriber number (SN). Numbers have a ‚+‘-sign prefix. The calling party‘s number is found in the From: header field and the called party‘s number in the To: field.

Value

SIP Header

Format

Example

Caller ID (A number)

From:

+

+49231123456

Called party (B number)

To:

+

+49231123456