Abstract: A method of providing for customer selection of a circuit selection algorithm for use in a public network comprises the steps of storing a plurality of circuit selection algorithms in public network memory, translating a routing number for a call into customer data, matching the customer data with a trunk block circuit selection algorithm and controlling the delivery of calls to a customer in accordance with the trunk block circuit selection algorithm. The customer may also custom design their own circuit selection algorithm and input their custom designed algorithm into public network memory along with others for selection in accordance with their customer criteria, for example, time of day or day of week, low traffic period, high traffic period or other criteria.

Abstract: In a communication network, a method and apparatus is provided to detect the presence of loopback errors over facilities interconnecting switches of the network. According to the test protocol, an originating switch generates a tone on a forward trunk associated with the facility and monitors the return trunk for the presence of that tone. If the return trunk contains the tone, the originating switch fails the facility for a loopback condition. The loopback test protocol complements conventional continuity tests and results in greater reliability of communications networks.

Abstract: A method of providing for customer selection of a circuit selection algorithm comprises the steps of storing a plurality of circuit selection algorithms in memory, translating a routing number for a call into customer data, matching the customer data with a trunk block circuit selection algorithm and controlling the delivery of calls in accordance with the trunk block circuit selection algorithm. The customer may also custom design their own circuit selection algorithm and input their custom designed algorithm into memory along with others for selection in accordance with their customer criteria, for example, time of day or day of week, low traffic period, high traffic period or other criteria.

Abstract: In a large switching system, a complete record of a call through a network can be collected by having each switch that processes the call, record pertinent data and return the collected data to a particular switch where the collected data is stored. A complete call history simplifies network maintenance and permits precise identification of calling and called parties on a call-by-call basis.