Cisco 7925 is the leading model with best characteristics, firstly of all it has to be used by a company’s top management team, (Cisco UC Phone 7975, Gig Ethernet, Color).
Citel PBXgateways are installed at the central PBX location, and EXTenders are deployed at branch offices, call centers, or at home offices over managed IP connections, DSL, cable, or analog circuits