1. ITU-T Recommendation G.711. General Aspects of Digital Transmission Systems. Terminal Equipments. Puse Code Modulation (PCM) of Voice Frequencies. 1988. Online verfügbar unter [ITU-Web].
2. www.itu.int Webseite der International Telecommunication Union.
3. ITU-T H.323 Series H: Audiovisual and Multimedia Sustems. Infrastructure of Audiovisual Services - Systems and Terminal Equipment for Audiovisual Services Packet-Based Multimedia Communications Systems. 2009. Online verfügbar unter [ITU-Web].
4. Franks, J., P. Hallam-Baker, J. Hostetler, S. Lawrence, P. Leach, A. Luotonen und J. Stewart: HTTP Authentication: Basic and Digest Access Authentication. IETF RFC 2617, 1999. Online verfügbar unter [IETF-Web].
5. www.ietf.org Webseite der Internet Engineering Task Force.