A method of performing communication by using a plurality of network interfaces mounted on a communication terminal apparatus and a communication terminal apparatus are provided. The method includes allocating different Internet protocol (IP) addresses corresponding to the plurality of network interfaces to a plurality of applications of the communication terminal apparatus, relaying data transmitted or received between the plurality of applications and the plurality of network interfaces based on the allocated IP addresses, and simultaneously performing communication with an external network by the plurality of network interfaces through the relaying of the data.