Voice over IP (VoIP) lets you manage all your voice and data traffic over one network system. The VoIP model is appealing to those who manage a complex telecom infrastructure in which telephone calls cost as much as, if not more than, the cost of running the existing data network. Although VoIP is still a new technology, it shows great promise as a future industry standard.
The products listed in this Buyer's Guide are back-end switches that enable VoIP over your entire network and will let you replace your traditional PBX and phone-switch telecom infrastructure with a unified voice and data network. These products are not standalone Internet telephone-call software products, which let you connect either to another user with the same software or to an Internet-connected phone switch to make long-distance telephone calls.
One common denominator among the VoIP products listed in this Buyer's Guide is the H.323 standard set by the International Telecommunications Union (ITU), which sets standards for multimedia communications over LANs that don't provide a guaranteed Quality of Service (QoS). The H.323 standard provides a foundation on which audio, video, and data communications can collaborate across IP-based networks, including the Internet. The H.323 standard provides interoperability between multimedia products and applications from multiple vendors, allowing users to communicate without concern for compatibility.
Before deploying a VoIP solution, you need to attend to concerns such as the cost of telephony service versus data service, how to integrate the VoIP solution with existing PBX systems, and how to integrate the VoIP solution with virtual PBX systems such as Centrex that use equipment to which you don't have access. Furthermore, the problems you can encounter when deploying VoIP solutions require that you have a strong relationship with your VoIP infrastructure hardware vendor. Contacting the vendors listed here will put you on the right path to VoIP research and deployment.