As IP Telephony product portfolios mature, and organizations see more examples of the real costs and benefits of implementing IP Telephony, one of the last major inhibitors to adoption is security. Voice is, after all, a critical infrastructure component for most organizations, and such a dramatic change is frightening enough just to implement, without even considering how a successfully implemented system could be susceptible to attack.
You may be in a position where you've been asked to identify the security risks and demonstrate a capability to mitigate these risks before an organization will be willing to take a chance on IP Telephony. This can be quite a challenge because of the distributed nature of the softswitch, since call control, voice, management, and all sorts of telephony traffic must traverse the IP network between gateways, stations, servers, proxies, etc. There is, frankly, no shortage of places to attack the system.
While many readers of searchnetworking.com tips are capable of dealing with individual threats on a technical level, it's often difficult to come up with a comprehensive plan that resonates with management on how to deal with IP Telephony security without being too nuts and bolts.
Fortunately, there are several places to go to get good high-level information. One example is the METAGroup's IPT Conceptual Model and their IPT Security Reference Framework. These documents can really help ensure you have a well-thought-out
Thomas Alexander Lancaster IV is a consultant and author with over ten years experience in the networking industry, focused on Internet infrastructure.
This was first published in August 2003