Abstract: With the help of a key management protocol, the transmitted key information is authenticated by at least one certificate signed by the terminals, and at least one fingerprint of the public keys or certificate, which were used for authenticating the key information, is added to the useful part of an SIP message. The identity information present in the header of an SIP message is additionally copied into a region of the header or the useful part, and a signature is produced by way of the fingerprint, the datum information presented in the header of an SIP message, the copied identity information, and optionally the certificate reference information, and is inserted into a further region of the header of the SIP message. The additional signature that is produced and inserted can remain uninfluenced during a transmission across several networks of different network operators.

Abstract: With the help of a key management protocol, the transmitted key information is authenticated by at least one certificate signed by the terminals, and at least one fingerprint of the public keys or certificate, which were used for authenticating the key information, is added to the useful part of an SIP message. The identity information present in the header of an SIP message is additionally copied into a region of the header or the useful part, and a signature is produced by way of the fingerprint, the datum information presented in the header of an SIP message, the copied identity information, and optionally the certificate reference information, and is inserted into a further region of the header of the SIP message. The additional signature that is produced and inserted can remain uninfluenced during a transmission across several networks of different network operators.

Abstract: With the help of a key management protocol, the transmitted key information is authenticated by at least one certificate signed by the terminals, and at least one fingerprint of the public keys or certificate, which were used for authenticating the key information, is added to the useful part of an SIP message. The identity information present in the header of an SIP message is additionally copied into a region of the header or the useful part, and a signature is produced by way of the fingerprint, the datum information presented in the header of an SIP message, the copied identity information, and optionally the certificate reference information, and is inserted into a further region of the header of the SIP message. The additional signature that is produced and inserted can remain uninfluenced during a transmission across several networks of different network operators.

Abstract: With the help of a key management protocol, the transmitted key information (si) is authenticated by at least one certificate signed by the terminals (A, B), and at least one fingerprint (fp) of the public keys or certificate, which were used for authenticating the key information (si), is added to the useful part of an SIP message (INVITE). The identity information (idi) present in the header (SIPH) of an SIP message is additionally copied into a region of the header (SIPH) or the useful part (B), and a signature (S) is produced by way of the fingerprint (fp), the datum information (di) presented in the header (SIPH) of an SIP message, the copied identity information (idi?), and optionally the certificate reference information (hz), and is inserted into a further region of the header (SIPH) of the SIP message (INVITE).

Abstract: In one aspect, a multi-media connection is established in a communications system based on packet oriented communication with at least a first station only supporting IPv6 data-packets, at least a second station only supporting IPv4 data-packets and at least a media relay station. A communication between the first station and the second station is at least partially established via the media relay station. A terminal and a media relay are also provided.

Abstract: In one aspect, a multi-media connection is established in a communications system based on packet oriented communication with at least a first station only supporting IPv6 data-packets, at least a second station only supporting IPv4 data-packets and at least a media relay station. A communication between the first station and the second station is at least partially established via the media relay station. A terminal and a media relay are also provided.