Open Charging and QoS Interfaces for IP Telephony

IP (Internet Protocol) Telephony requires the support of guaranteed services and charging to provide a valuable service for potential customers. It has to be considered carefully, that the quality of long-distance telephony calls via the Internet is heavily affected by the load of the links which the call has to traverse. As these different quality requirements of users will exist, the Internet has to support different service classes. Therefore, an advanced services network model is required. In turn, and that is the main motivation for this work, if at least two traffic classes will exist in the Internet, there must be the right incentive for any user to choose the traffic class which optimally fits his requirements and will be the most efficient one in terms of prices to be payed. Therefore, the integration of charging and Quality-of-Service (QoS) interfaces for IP telephony are important to stimulate future use of the Internet. This papers gives a first overview of OCIT (Open Charging Interfaces for IP Telephony), an experimental platform for standardsbased IP phones that are enhanced with QoS and charging support.