Sunday, May 15, 2005

Columbitech Securing WiFi VoIP

Tom Keating - VoIP Blog

Since I've been talking about dual mode WiFi cellular quite a bit lately (see this and this for starters) I thought I'd share this news release which claims "seemless" handoff of calls from cellular to WiFi and vice-versa. It also addresses securing wireless VoIP.
Columbitech Adds VPN Support for Securing Wireless VoIP Applications
Users can roam between networks without dropping calls
Wireless security software developer Columbitech today announced wireless VPN support for securing wireless voice applications (wVoIP). This new release contains security framework enhancements that provide protection for making reliable and robust VoIP calls. Users who have wVoIP capabilities are able to securely check e-mail and voicemail, and have access to corporate files. Columbitech takes a holistic approach to secure the converged IP networks with no limitations to bandwidth or applications.
The Columbitech WVPN provides built-in support for Session Persistence – that is, the ability to maintain a session while being out of wireless coverage. The most important requirement when it comes to wVoIP is to maintain the session, so that the call will not be cut off. For users, this means that once initiated, a call will not be cut off because of a disruption of network coverage, like poor WLAN signal strength. The Columbitech WVPN makes it possible to resume and continue a call that was initiated at a WLAN hotspot over a public 3G network or over any packet switched IP network. The Columbitech WVPN is a session-based VPN.
The solution also provides TCP connection multiplexing to prevent flooding the wireless link with redundant TCP retransmissions during handover. In short, the available bandwidth will be used to transport actual traffic instead of redundant TCP retransmissions. If the entire link capacity is utilized for retransmissions, TCP will eventually break down due to lack of new user data on the link. However, if all data were multiplexed over one TCP Session, there would be plenty of room for new data to reach the receiver and the applications would be more likely to survive a bad connection.
When moving between WLAN and a packet switched public WAN, such as GPRS, the difference in bandwidth can vary by a ratio of 1000. Therefore, to adapt the speed to the road conditions, Columbitech uses TCP’s built-in mechanisms for flow control, together with proprietary messages between client and server, to ensure that the call will not be cut off and to make network roaming as smooth as possible.
In order to offer the user the best performance possible, large data packets such as file transfers are compressed, typically doubling the perceived performance. Columbitech WVPN intelligently chooses when and what to compress in order to reduce the amount of data sent over the air. Since Columbitech Wireless VPN is designed to support adaptive compression, it is possible to distinguish between wVoIP traffic and data applications and apply appropriate actions.
“Data and voice convergence are very compelling from an application point of view, but very challenging from a security point of view,” said Ã…sa Holmstrom, President of Columbitech. “The same security threats that enterprises have been facing regarding data are now also a reality for voice. With the Columbitech Wireless VPN, enterprise users can protect both their voice and data applications and resources with a solution that is optimized for wireless networks.”
Many enterprises depend on real-time access to data and applications. The growing convergence of voice and data networks only exacerbates the security risks of cyber attacks. The Columbitech Wireless VPN has been designed to secure not only data, but also voice. VoIP networks are subject to a number of security weaknesses, such as virus attacks on IP PBXs, hackers breaking into VoIP gateways to make free calls and eavesdropping through VoIP phones. Columbitech’s solution provides a secure solution to this problem.
About Columbitech: Recognized as a leader in Wireless LAN and WAN security, Columbitech develops and markets software products for secure wireless access to corporate data without sacrificing performance and ease-of-use. There have been more than 4,500 server and 250,000 client licenses sold. Users include service technicians, retailers, all levels of military and government branches, and other mobile staff who require proven reliability and security for their wireless communications. The company’s proven and standards-based technology is OEM licensed by leading companies, including Symbol Technologies, Hewlett Packard and Ericsson. Columbitech's solution also has FIPS 140-2 certification and is in the process of being evaluated for NIAP Common Criteria Certification. Columbitech’s products are built from the ground up for the wireless world, offering end-to-end security, convenient always-on connectivity, and optimized performance. Privately-held Columbitech has offices in Stockholm, Sweden and in New York, USA. For more information, please visit


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