Voice gateway and route selection

A gateway apparatus selecting a route for transmitting voice through gateways connected an IP network, comprising:

• means for multicasting a connection request to receiver gateways along routes running through the receiver gateways;
• means for receiving responses to the connection request from the receiver gateways;
• means for finding a network delay time and a device delay time of each of the receiver gateways according to the responses, calculating the sum of the network delay time and device delay time of each receiver gateway, and calculating a compression or decompression allowance time of each route of the receiver gateways by subtracting the calculated sum from a preset allowable delay time;
• and
• means for selecting one of the routes that employs a compression rule whose compression or decompression time is shorter than the calculated compression or decompression allowance time of the corresponding receiver gateway.