Fully distributed message storage facilities in a distributed switching

Abstract

Storing messages intended for a communication terminal in a service circuit associated with the local network of a switch node serving the communication terminal. A switch node may have one or more local networks and can use a service circuit of these networks to store the message. If the switch node does not have capacity to store the message, the switch node will request that another switch node store the message. When it is necessary to process and store a message for a communication terminal connected to a local network, the service circuit associated with the local network may be busy and unable to process the call or the service circuit may not have sufficient memory to store a message. In which case, the switch node will attempt to find a service circuit with the ability to process the message and store the message on another local network controlled by the switch node. If the switch node cannot find a single service circuit that has both processing capability and storage capability, the switch node will attempt to find a service circuit on one local network that has processing ability and a service circuit on another local network that has storage capacity. The message is then stored on a local switching network of the other switch node. If the switch node request another switch node store the message, the other switch node uses the same procedures described above for identifying a service circuit and storage capability.