Patent ID: 7333500
Filing Date: 2008-02-19
Classification: H04L

Abstract:
1. A method of determining a presence of a Network Address and Port Translator between a Telephony Service Provider Network and a network comprising a Media Gateway, said Telephony Service Provider Network comprising a Media Gateway Controller, said method comprising: the Media Gateway Controller instigating a test call between a first virtual endpoint on the Media Gateway Controller acting as a calling party, and an endpoint on the Media Gateway acting as a called party by transmitting a Create Connection message to the endpoint on the Media Gateway; receiving a reply comprising a local Session Description Protocol of the endpoint of the Media Gateway at the Media Gateway Controller; receiving an empty/noise media packet from the Media Gateway at the first virtual endpoint of the Media Gateway Controller; and comparing source IP address and port of the empty/noise media packet received at the first virtual endpoint of the Media Gateway Controller with IP address and port contained in the received local Session Description Protocol of the endpoint of the Media Gateway, wherein if the IP addresses are different or the ports are different then a Network Address and Port Translator is determined to be present, otherwise, if the IP addresses are the same and the ports are the same then a Network Address and Port Translator is determined not to be present.