This invention relates to the field of Internet Protocol communications. More particularly, this invention is a method for setting up, authorizing, maintaining, and terminating an IP telephony session with quality of service across the Internet by combining session initiation protocol, resource reservation protocol, common open policy service, and open settlement protocol. The method of this invention allows an IP telephony session to benefit from all these protocols. With reference to the figure, an embodiment of this invention involves an SIP client (115, 130, 135, 136) that uses SIP and RSVP; SIP proxy servers (150, 151) that use SIP and COPS; policy servers (140, 141, 142) that use COPS and OSP; a clearing house server (180) that uses OSP; and several routers that use RSVP and COPS (e.g., 160, 161, 170).

METHOD FOR PROVIDING IP TELEPHONY WITH QoS USING END-TO-END RSVP SIGNALING

In one embodiment, a network system of the present invention includes at least a first router and a second router coupled to an upstream link to permit data flow from the first router to the second router across the upstream link. The second router includes a control plane and a data plane having an input port coupled to the upstream link and an output port connectable to a downstream link. The control plane includes a virtual pool having a capacity corresponding to a resource capacity of the first router and an admission control function. In response to a request to reserve resources for a flow through the data plane from the input port to the output port, the admission control function performs admission control for the upstream link by reference to resource availability within the virtual pool. In one embodiment, the request is a request to reserve resources for an Integrated Services flow, and the capacity of the virtual pool corresponds to a resource capacity of a Integrated Services service class supported by the first router.

Pool-based resource management in a data network

A data network may include an upstream router having one or more data handling queues, a downstream router, and a policy server. In one embodiment, the policy server includes processing resources, a communication interface in communication with the processing resources, and data storage that stores a configuration manager executable by the processing resources. The configuration manager configures data handling queues of the upstream router to provide a selected bandwidth to one or more of a plurality of service classes of data flows. In addition, the configuration manager transmits to the downstream router one or more virtual pool capacities, each corresponding to a bandwidth at the upstream router for one or more associated service classes among the plurality of service classes. In one embodiment, the configuration manager configures the data handling queues on the upstream router only in response to acknowledgment that one or more virtual pool capacities transmitted to the downstream router were successfully installed.

Policy-based synchronization of per-class resources between routers in a data network

The quality of service existing in a data packet network during the course of communication of a voice call through a data network, such as the Internet, is monitored. A minimum acceptable level of service may be predefined with a threshold quality level stored in the user's Call Processing Record (CPR) in the AIN Integrated Services Control Point (ISCP). If the monitored quality is maintained in excess of the stored threshold, communication of the call continues through the established course of transmission. If the measured quality of service on the data network is not satisfactory, the routing of the call is changed to communication solely through a voice telephone network connection, which may include an Interexchange Carrier link, without terminating the call. The packet data network is thereby bypassed to obtain voice grade quality while maintaining the call.

Packet data network voice call quality monitoring

A switched telephone network is arranged in a manner to enable packet voice communication between telephone terminals via multiple redundant packet switched networks. The packet switched networks may utilize different protocols, be operated by different entities, and have primary functions other than voice communication. One example of such a network may be internetworked networks, such as the Internet. One example of an alternate packet switched network may be a network whose primary function is control of a circuit switched telephone network. The common channel interoffice switching system (CCIS) of a public switched telephone network (PSTN) is a preferred example. A voice communication link may be established from telephone terminal to telephone terminal via the Internet, the quality of voice communication may be monitored, and the link may be transferred to the common channel interoffice signaling network if and when the quality of voice communication deteriorates beneath a pre-established norm. There is provided a means for monitoring the links of the common channel interoffice signaling system carrying the packetized voice communication and collecting the information needed to permit charging for the voice communication by time duration or by cells used to carry the packetized voice signal. The customer may be provided with the option of establishing the norm for diversion of the communication, or may elect which path is to be selected as the primary path.

Telephony communication via varied redundant networks

Currently two approaches to provide quality of service in the Internet are being discussed. An early one is the Resource Reservation Protocol, RSVP, (IETF RFC 2205) based on an end to end approach. Recent and ongoing activities in the IETF's Differentiated Service Working Group are focused on methods for providing quality of service in backbones. This paper presents a concept for the integration of both integrated and differentiated services, describes a prototype implementation, and presents evaluation results. Additionally the paper discusses business aspects arising from this service translation.

F. Baumgarter

Papers

A concept for RSVP over Diffserv