A clearinghouse server for routing multi-media communications, including telephony calls, between a source device and a destination device via a distributed computer network, such as the global Internet. The clearinghouse server can authorize the completion of a communication from a source device to a destination device and collect usage-related information for the completed communication. In response to an authorization request issued by an enrolled source device, the clearinghouse server can identify one or more available destination devices available to accept a communication from an authorized source device. The clearinghouse server can provide a list of the identified destination devices, typically organized in a rank order, by sending an authorization response to the source device. In turn, the source device can use this list to select a destination device and contact that selected device via the computer network to complete the communication.

A peering authority or settlement clearinghouse can be used to control access, collect session accounting information, and provide financial settlement of interconnect or session fees among anonymous Internet Protocol (IP) peers or networks. The addition of peering policy criteria, such as price and quality of service, to peer to peer route discovery mechanisms enable a trusted intermediary, such as the settlement clearinghouse, to authorize acceptable interconnection or peering sessions between anonymous IP peers. Any financial settlement transactions which result from the peering sessions may be subsequently executed by the settlement clearinghouse.

The present invention proposes a method for generating a real time billing information in a packet switching based network and a network element for implementing Interworking between a circuit switching based network and a packet switching based network, wherein a call is set up between a user of said packet switching based network and a user of a circuit switching based network, and a billing server is informed of at least a billing rate and an interval of billing, said method for generating a real time billing information comprising: generating a first message with a first token indicating the billing rate upon receiving a first charge message containing said billing rate from said circuit switching based network and based on said first charge message, and the billing server is informed of said billing rate; once said call having been set up, generating a second messages with a second token indicating the interval of billing upon receiving a subsequent charge message containing said interval of billing and based on said subsequent charge message, and the billing server is informed of said interval of billing; and generating a real time billing information by said billing server.