A communication system comprises a network server connected to a telephone at a customer premises via a subscriber line. The server is further connected to a cellular communication device through a cellular network. Upon installation of telephony equipment at the customer premises, a service technician uses a cellular communication device to communicate with the server of the network such that the server initiates a voice call to the telephone via the subscriber line. The technician then takes the telephone off hook, aligns a speaker of the cellular communication device with a microphone of the telephone, and aligns a microphone of the cellular device with a speaker of the telephone such that the telephone and the cellular device are acoustically coupled. A plurality of acoustic tones are communicated between the telephone and the cellular communication device in order to test the quality of the inbound and/or outbound connections for the telephone.