The present subject matter relates to methods, systems, devices, circuitry and equipment providing for communication service to be transported between first and second networks, and which monitors the communication service and/or injects test signals, and which can provide redundancy. At least one demarcation point or line is established between the first network and the second network, and/or between the first network, the second network and/or a third network. The Circuitry comprises a plurality of input amplifiers, output amplifiers, and multiplexer switches between a plurality of Port connectors. An SFP module or a WSFP module is inserted in the Ports.