XCAL-MPM4 is the smallest and yet most flexible of Accuver’s network benchmarking solution. The XCAL-MPM4 scales four ports (supporting four simultaneous phones). Each port comes with its own individual sound control, allowing independent standard-based voice quality (MOS) testing that can be used for both mobile-to-mobile or mobile-to-landline test scenarios. The unique feature of this tool is that any phone that supports Bluetooth, can be used for voice quality analysis ? proving that high quality, scalable and robust network benchmarking tools need not cost the earth.