Terminal Equipment and Call service system based Internet Protocol

摘要

The present invention provides an Internet protocol based call service based on a communication network in which the network state can be changed, such as a wireless network, the Internet capable of appropriately performing call processing in response to a network obstacle using a keep alive message A terminal device for a protocol-based call service and an Internet protocol-based call service system, wherein the terminal device performs a call process corresponding to any one of a call connection, a call, and a call connection end with a call control device, while a wireless channel Depending on the signal strength and whether the bearer is changed, the operating conditions of the keep-alive message including one or more of the transmission cycle of the keep-alive message, the number of re-transmissions of the keep-alive message, and the expiration time for waiting for a response are varied, and accordingly, the keep-alive message Net by operating a message The call processing procedure can be efficiently processed in consideration of the work obstacle.