Method of maintaining a connection and electronic apparatus using the same

A method of maintaining a network connection, used between an electronic apparatus and a server, the method comprising:

• (a) sending an Nth test packet to the server, wherein the Nth test packet requests that the server reply to the electronic apparatus after waiting for an Nth time interval, wherein N is a positive integer;
• (b) determining whether a reply for the Nth test packet is received, wherein the reply is sent by the server;
• (c) repeating sending the Nth test packet to the server if the reply for the Nth test packet is received;
• if the reply for the Nth test packet is not received, repeatedly sending an (N−1)th test packet and determining whether replies for all the (N−1)th test packets which are repeatedly sent by the server are received;
• (d) if the replies for all the (N−1)th test packets repeatedly sent by the server are received, calculating a time from the (N−1)th test packet being sent to the reply from the server being received as a period;
• if not all the replies for all the (N−1)th test packets repeatedly sent by the server are received, calculating a time from an (N−2)th test packet being sent to a reply for the (N−2)th test packet from the server being received as the period;
• and
• (e) sending a keep-alive packet to the server according to the period for maintaining a connection between the electronic apparatus and the server when the electronic apparatus is switched to a standby/sleep mode.