Integrated Voice and Data System

Agencies have three ways to deploy voice-over-IP (VOIP) services. Each isdesigned to support a specific network configuration and type of customer.


A gateway sits between a telephone system, such as a PBX or a centraloffice switch, and a data network, such as the Internet, and translatescalls from one format to another. Gateway functionality can be packagedin a number of different ways: dedicated devices, add-on cards for voiceproducts and software for local-area network servers.

Because there is such a large installed base of voice equipment, manyvendors have focused on this approach first. Established companies suchas Cisco Systems Inc., Lucent Technologies, Nortel Networks Inc. and NokiaLtd., as well as newcomers such as Clarent Corp. and VocalTec CommunicationsLtd., offer those products. Although the devices can be used within enterprisesor on carrier networks, the initial emphasis has been on the carrier segment.

Internet Protocol Private Branch Exchange

An IP, or software, PBX is a specialized computer system that replacesa company's traditional voice system. The devices — which usually are installedwhen a company makes a dramatic change, such as moving into a new building— support IP voice transmissions all the way down to a user's desktop. Companiessuch as AltiGen Communications Inc. and Artisoft Inc. have been in the marketfor about five years. Cisco and 3Com Corp. gained entry by acquiring smallstart-up firms during the past year. Recently established PBX vendors suchas Lucent and Nortel have been adding this functionality to their systems.

The devices have been geared to small- and medium-size enterprises.Scalability has been an issue with these products; their top capabilityhas been a few hundred users. Recently, vendors have begun to deliver systemsthat can support tens of thousands of users.

Integrated Voice and Data System

Integrated voice and data systems treat VOIP as just another applicationon a corporate LAN. These systems often have a number of functions, suchas messaging, in a device geared to handle a company's data and voice needs.Praxom Inc. and Vertical Networks Inc. are two of the leading suppliersin this space. These systems can be used in small organizations (a few hundredemployees) and a large agency's branch offices.


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