: Contains the international E.164 number from the user, as obtained from CS Networks signalling.
: Contains the IP address or FQDN of the originating MGCF.
: The MGCF inserts the TEL URL containing the subscriber number, as received from the CS network.
: The MGCF inserts this header and populates the icid parameters with a globally unique value.
: SIP URI that contains the IP address or FQDN of the MGCF.
: Contains a preconfigured set of codecs supported by the MGW.