VoIP Calls Can Be Intercepted

Can VoIP telephony packets on a computer network be intercepted? Yes, they can. What does it take to intercept VoIP packets? The same equipment and access that it takes to intercept computer data packets. How feasible is it? Not very.
After spending millions of dollars, the FBI developed a system called Carnivore that is essentially built on earlier network management technology known as a protocol analyzer. Basically, the device (a souped-up computer) plugs into a network much like any other network addressable device. It sits there and collects packets as they race by at the speed of light. The packets can then be analyzed for threats and other information, or so the theory goes.
If you’re worried about such a device, keep the following in mind:
A government agency at least as powerful as the FBI is required to gain access to a given network (excluding a trusted person doing it).
Access must be physical. The person must have a key to the telecommunications closet or access to an office where they can plug into the network.
Access is achieved through the network operating system, so the person must have a network access account.
Network managers today have a variety of techniques to protect their packetized network traffic.
After all this, if you’re still concerned about VoIP packet interception and security, consider the fact that anyone on the street can tap a POTS telephone line with a simple analog handset and a few wires. All they need is physical access to your line. They do not have to be inside your company; they can access the line from the street or in tunnels where the public access lines run.
A solid argument can be made that a packetized network has more security than the older circuit-switched network, particularly because you can also implement data encryption for VoIP.