VoIP is a time sensitive technology

VoIP is a time sensitive technology. Calls must be set up and authenticated, and voice packets must arrive at their destination without interruption and on time. This requires a near continuous network stream, uninterrupted by less sensitive data transmissions. The implementation of Quality of Service techniques on wired LANs assure that these voice packets receive priority, and call quality issues such as latency, jitter, and packet loss have been sufficiently addressed.

Enter the standards based wireless network, a technology in an earlier stage of development, and more challenges occur. While today's wired network provides plenty of bandwidth for both voice and data to coexist, WLANs provide less bandwidth, and Quality of Service issues must be revisited. Security measures such as authentication and encryption must be implemented and can add to the problem by increasing the size of the voice packet. Additionally, users on the move will traverse wireless access points where handoffs must be quick and smooth.

Companies wishing to implement wVoIP must take security issues into consideration from the start. As in any IP network, the dangers of hackers, denial of service, highjacking and spam, all lurk in the shadows.

Because a wireless network uses radio frequencies as its transmission media, the security normally provided by a firewall in a wired network is not sufficient, simply because of the physics. Whereas to break into a wired LAN requires hackers to either physically be inside the network or to hack in through the Internet, in a WLAN they can grab network transmissions from the air while parked across the street. The security issues that network managers must consider in a VoWLAN are the privacy of conversations, and the protection of the network infrastructure.

For WiFi networks, security has had a shaky start with the implementation of WEP as its security mechanism. WEP provides for authentication and encryption between the user and the access point, and was found to be easily hacked. The 802.11i standard, adopted as WPA2 (Wireless Protected Access), provides for more robust security by requiring two way authentication between the user and the network, and uses AES (Advanced Encryption Standard) as its encryption engine.

As network managers plan the rollout of a wireless VoIP network, the greatest security threat they face is improper implementation. Building security into the design of the initial deployment can, and should affect the network topology, as well as material costs. Failure to do so could lead to further expenses in loss of services and network redesigns in the event of compromise.