An Admission Control Model Through Outband Signalling Management

A dynamic window model is developed which provides admission control for circuit switched networks through the signalling network. This model incorporates distributed processing while achieving desired global congestion control effects. It reflects the interaction between the circuit switched path in the telephone network and the packet switched path in the signalling network. The model is solved by applying the concept of parametric analysis to study the whole circuit switching subnetwork as a composite server. The variant service rate is derived for the composite server of the circuit switch trunk in the context of a closed chain where the arrival of call services is finite. To avoid the overtlow and the combinatorial complex problems, the computation is reduced into the Erlang recursive f m . Mean value analysis formulae are derived for the model. Examples are given to demonstrate the validation of the analysis. manner [14]. One example of current limited control is to recognize the incoming source address when the calling process finds no remaining link capacity available. Then an indication signal is sent to the upward node one hop ahead. Based on this indication, the previous node can block the other call requests. This kind of simple control solution is far from being satisfactory due to the arising potential problems. First looking at one hop ahead does not provide enough information along the whole path. Thus no real end-to-end control is available. Second there is the unfairness problem, because all call requests may be rejected with the same probability even if they are from a light traflic source which consumes less resources. Among other problems is the unmatched timing scale of the telephone networks and the control networks. Setting up a virtual circuit may take seconds of time while the processing of a call request is within milliseconds. Without p r o p control, the signalling network may accept more calls than the telephone network can deal with, thus congesting the &cuit switched network complet&r.