VoIP has long since arrived in modern office communication and many users telephone via VoIP without even realizing it. But unification of the IP and PBX networks offers far greater benefits than simply phoning on the Internet. Unified Communications (UC) is the watchword that has captivated the specialist press and congresses of late. Not a great deal is required to introduce a Unified Communications solution in a company: A VoIP PBX, IP phones (or clients), as well as a SIP provider. But what do you do if you wish to keep your existing telecommunications infrastructure, but still use the options Unified Communications has to offer?