This is the key attribute of the CscfTelephonyClass containing all the Telephony parameters. One instance of the CscfTelephonyClass with the key CscfTelephony=default is created at startup. It is NOT possible to create new instances. The default instance can not be deleted.
This parameter defines the originating S-CSCF handling of the phone-context parameter at originating requests including a request-URI containing a local telephone number in a SIPURI or TEL URI form.