Companies and organizations all over the world are rapidly migrating from traditional systems, such as PBXs and video conferencing based on ISDN, to systems that use a fundamentally different architecture under which voice, data, video, and fax are all converged on a single platform and a single, Internet Protocol network.

Converged systems have been available for only a few years but already account for a majority of all spending on business communications systems. Leading manufacturers have all but discontinued production of traditional systems.

Why are businesses moving to convergence so rapidly? According to a survey conducted by Sage Research, the two reasons most often cited are cost savings and productivity gains.

Although most buyers focus on purchase prices, the initial cost of a traditional telephone system, for example, is only about half of the total cost of ownership (TCO). Thus, the TCO for a $25,000 system could easily be $50,000 over the full life cycle of the equipment.

Read more...

IP-PBXs are rapidly replacing traditional PBXs and key systems. There are a number of reasons for this trend, but our purpose here is to explain how IP-PBXs work.

Requirements

For an IP-PBX to work, it needs to replace the key functions of a traditional PBX:

• Call Control
• Interface with the public switched telephone network (PSTN)
• Support user phones

  Read more...

As of this writing, security threats to VoIP are more hypothetical than real; there have been no significant instances of breached VoIP security. This is because most VoIP deployments are closed systems; almost no organization exposes its VoIP system to the Internet. However, once organizations begin to publicize SIP addresses on business cards and Web sites, for example, security will become an issue.

The history of the Internet teaches that it is wishful thinking to believe there will never be threats to VoIP. So use this time to build defenses that will work when the security threats arrive.

Although a number of threats have been identified, four are most significant:

• Spam over Internet Telephony (SPIT)
• Denial of Service (DoS) attacks
• Toll fraud
• Eavesdropping

  Read more...

Most networks today use TCP/IP. With TCP/IP, networks are “default-open” - any device that is connected to the network can connect to any other device on the network, and two (or more) networks can easily be connected with each other. There is little need for management or control.

The virtue of TCP/IP networks is that they give users access to the information they need, when they need it, and where they need it. But these features also make it easy for hackers, worms and viruses to invade the network.

The rise of abuse has shown that default-open, while ideal, is simply not practical. In response, vendors have developed a variety of network security solutions. For the most part, these solutions address discrete points of network vulnerability.

Read more...