1. A control arrangement for a communication switching system having first and second communication networks configurable independently from each other separately to provide first and second communications, respectively, for terminal logical channels of the system, the system further including first and second network control means for configuring the first and the second networks, respectively, in response to receipt of requirements signals, the control arrangement comprising: first program controlled means cooperative with both the first and the second network control means and operable in response to receipt of requirements signals and associated signals indicating the first communications for generating requirements signals for controlling the operation of the first network control means to configure the first network into at least one of (a) physical communication channels corresponding to the logical channels, and (b) physical communication paths betweenthe physical channels and corresponding to logical communication paths, and being further operable in response to receipt of requirements signals and associated signals indicating the second communications for generating requirements signals for controlling the operation of the second network control means to configure the second network into at least one of (a) physical communication channels corresponding to the logical channels, and (b) physical communication paths between the physical channels and corresponding to logical communication paths; and second program controlled means independent in program from the first program controlled means and operable in response to receipt of call signals and associated signals indicating either one of the first and the second communications for any one of the logical channels for processing call information to generate, both independently of and for association with the first or the second communication indicating signals, the requirements signals for controlling the operation of the first program controlled means to establish the logical communication paths between the one logical channel and another at least one logical channel, independently of both the first and the second networks and the first and the second network control means.