Patent ID: 8649819

Claim:
A method for providing PBX functionality for mobile phones, the method comprising: intiating, by a mobile phone, a phone call to an IP phone, the mobile phone associated with a mobile phone ID and the IP phone associated with an extension number; sending, by the mobile phone, the extension number to an integration device; sending, by the integration device, the extension number and the mobile phone ID to a mobile phone proxy, the integration device for allowing the mobile phone to use PBX functionality; translating, by the mobile phone proxy, the extension number into a PSTN number and determining, by the mobile phone proxy the IP phone that is being called; sending, by the mobile phone proxy, a connection number to an IP network, the connection number for the integration device to utilize to connect the phone call between the mobile phone and the IP phone; sending, by the IP network, the connection number to the integration device; causing, by the integration device, a mobile voice network to establish the phone call with the mobile phone; associating, by the mobile phone proxy, the phone call with the mobile phone and connecting the phone call with the IP phone; establishing a call control path between the mobile phone and a private branch exchange, the call control path including the mobile voice network; receiving, at the private branch exchange via the call control path, a call control command requesting to perform a PBX function from the mobile phone via the mobile phone proxy; and using the call control path between the mobile phone and the private branch exchange to perform the PBX function.