Patent ID: 8514847
Filing Date: 2013-08-20
Classification: H04L,H04M

Abstract:
1. A method for a switch to maintain connection with an Internet protocol phone operating behind a firewall, the method comprising: registering the Internet protocol phone in response to receiving a first registration request from the Internet protocol phone, the first registration request including first registration information, the first registration information including a first public Internet protocol address associated with the firewall; storing the first registration information; reregistering the Internet protocol phone in response to receiving a second registration request from the Internet protocol phone due to the firewall experiencing a public Internet protocol address change, the second registration request including second registration information different from the first registration information, the second registration information including a second public Internet protocol address associated with the firewall, the second public Internet protocol address being different from the first public Internet protocol address; and in response to detecting a failure associated with call processing for the Internet protocol phone after the reregistering of the Internet protocol phone using the second registration information, reverting to the stored first registration information to process calls associated with the Internet protocol phone.