With a SIP telephone you utilise the advantages of the world wide internet: you are always connected, regardless of your location. Your SIP telephone can travel with you. Away from the office, you can connect you phone to the internet when on vacation, and in seconds you are back at your workplace, accessible with the same telephone number.

Or take another example, you commute between a central and branch office and want to always be reachable under one telephone number; with a SIP telephone you no longer need to forward calls to your mobile telephone to be reached.