I have seen hotels using mitel 3300 with PMS without a 5550 console. Is the 5550 been replaced with all its features by these 5540/1000 consoles or do they co-exist. If they do then who handles the calls , the 5550 or the 5540/1000. How does the mitel 3300 interfaces to the PMS and sends call details without the 5550 console