Share lines internally and externally and in between. Over the internet or over the LAN. Over the fixed Line networks or over Mobile networks. You do not need a full one to one map of lines with the associated cost. You could map one to many and share the cost.
Even Skype lines can be mapped into these phones. Other low cost VOIP lines can be mixed in with this combination.
Conference calls, Video calls, IVR, voice mail to email are just a few of the many possible features.
Group your users by their roles, departments, ranks and more. One user can belong to more than one group. Increased flexibility from the analog or digital keyphones or PBX/PABX.