International Business Machines Corporation

Stephen W Babin

Michael Lee Masterson

John D Kari

Provided is a method for maintaining a Virtual Private Network (VPN) connection between a mobile device and a server over a wireless network in a manner that conserves the power supply of the mobile device and is suitable for connections that employ server-initiated traffic. After a successful login to a VPN server, a VPN client establishes a Transport Control Protocol (TCP) connection and a UDP connection with the server. After a power timeout, the server calculates the elapsed time between the current transmission and the last tunnel traffic. If the elapsed time exceeds a power timeout value, the VPN server transmits a simple control message to the client via the TCP channel. The client then reestablishes the UDP connection to the client and the server resumes transmission on the reestablished UDP channel.

Using a transmission control protocol (TCP) channel to save power for virtual private networks (VPNs) that use user datagram protocol (UDP)

Provided is a method, system and programming product for maintaining a connection between a mobile device and a server over a wireless network in a manner that conserves the power supply of the mobile device. The claimed subject matter addresses the transmission of regular 'keep-alive' packets to refresh a network address translation (NAT) server and the scanning for and connecting to faster, higher priority network connections. A configurable parameter, or power timeout, specifies an idle time. When a period of time equal to the parameter has passed with no traffic between the mobile device and the server, in either direction, periodic roaming scans and keep-alive messages are halted. As soon as traffic is resumed through the tunnel, the mobile device roams to the highest priority connection and roaming scans and keep-alive messages are resumed.

Pausing keep-alive messages and roaming for virtual private networks on mobile computing devices to save battery power

Provided is a method for maintaining a connection between a mobile device and a server over a wireless network in a manner that conserves the power supply of the mobile device. The claimed subject matter addresses the transmission of regular 'keep-alive' packets to refresh a network address translation (NAT) server and the scanning for and connecting to faster, higher priority network connections. A configurable parameter, or power timeout, specifies an idle time. When a period of time equal to the parameter has passed with no traffic between the mobile device and the server, in either direction, periodic roaming scans and keep-alive messages are halted. As soon as traffic is resumed through the tunnel, the mobile device roams to the highest priority connection and roaming scans and keep-alive messages are resumed.

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Cedar Park, TX, United States of America

Stephen W Babin