Patent ID: 9537821
Date: 2017-01-03
CPC Classifications: H04L,H04W

Claim:
1. A method for a network communication system comprising a user equipment, a gateway comprising a Policy and Charging Enforcement Function, an application function, a Policy and Charging Control Function and a Network Address Translator; where wherein the Policy and Charging Control Function communicates with the Policy and Charging Enforcement Function and the application function; wherein the user equipment connects to a network, wherein a Gx session is started between the Policy and Charging Enforcement Function and the Policy and Charging Control Function; wherein the user equipment starts a service session with the application function such that service signaling passes via the application function, wherein an Rx session is created between the Policy and Charging Control Function and the application function, and wherein a Network and Port Address Translator is positioned between the user equipment and the application function for handling the service session, characterized in that a message is sent to the Policy and Charging Control Function every time a new Network Address Translator binding is created or an old Network Address Translator binding is removed, such that the Policy and Charging Control Function is aware of any Network Address Translator bindings of the user equipment, the message comprising information associating a first IP address and a first port assigned to the user equipment for a network connection with a second IP address and a second port provided by the Network Address and Port Translator, wherein the gateway and Network Address Translator and the Policy and Charging Control Function use a common algorithm to determine what port numbers are assigned to the user equipment on the outside of the Network Address Translator, wherein using a common algorithm to determine what port numbers are assigned to the user equipment on the outside of the Network Address Translator comprises generating port ranges based at least in part on a monotonically increasing counter, such that each time a session for a specific IP address is created, the gateway and Network Address Translator and the Policy and Charging Control Function increase the counter by one.