The cost effectiveness of voice over Internet Protocol (VoIP) undoubtedly evokes, at a minimum, curiosity on the part of corporate decision makers considering how to strategically proceed toward the goal of cost effective – yet robust – voice communication. However, is VoIP technology really the best solution for startups, or even established companies? The cost effectiveness is plainly evident, but are there other items, such as security, that should be considered prior to a VoIP implementation? Network architects, system administrators and security specialists would be wise to account for the following issues prior to leaping into the emerging world of VoIP. (To learn more about VoIP trends, see The Global VoIP Revolution.)
Traversing the Firewall
When configuring an organization’s network boundary in a typical data network, a logical first step is inserting the proverbial 5-tuple information (source IP address, destination IP address, source port number, destination port number and protocol type) into a packet filtering firewall. Most packet filtering firewalls examine the 5-tuple data, and if certain criteria is met, the packet is either accepted or rejected. So far so good, right? Not so fast.