The revolution in telecommunications is happening around us with the convergence of voice, fax, and multimedia services on unified, packet-based networks. Between now and 2002 the number of call minutes (including voice, fax and data) transmitted using IP telephony (IPT) systems is expected to have a compound annual growth rate of 325%, and sales of Voice over Internet Protocol (VoIP) are expected to increase exponentially.
Internet Protocol networks (IPs), whether public, dedicated, or private corporate, have become the next generation telephone networks. IPs are rapidly becoming the new standard for both consumer and enterprise telecommunications. They carry voice, fax and other data - all on a single backbone network - and can interconnect with other networks.
IP telephony refers to the transmission of voice and fax communications as packet-switched media streams over IPs. In the past, telephone traffic was exchanged over a circuit-based network commonly referred to as the public switched telephone network (PSTN). This is comprised of a network of circuits connected by the switching systems of the many local and long distance telephone companies worldwide. A voice conversation requires an end-to-end connection which stays in place and uses up bandwidth on the circuit for the duration of the call. During the call, the signal may be converted from analog to digital form and back to analog at the distant end.
Essentially, IPT is implemented through a gateway switch that serves as an interface between IPs and PSTNs. The gateway transmits the voice conversation by breaking up the signal into digital packets and sending it over the data network. The gateway at the receiving end decompresses the call and returns it to a circuit-switched network or PBX to complete its route to the destination telephone.
IPT solutions revolutionize business communications by using a single network to support voice, fax, and data applications. Benefits include:
* drastically reduced cost of internal and external telephone and fax calls worldwide
* improved flexibility, manageability, and ease of use of communications technology
* a foundation for integrated communications services and applications - from unified messaging to multimedia and video
* seamless integration with existing routers and PBXs
* extending call management features provided by Centrex to remote sites, home offices and telecommuters
* allowing for a more efficient use of bandwidth because packets of other types of transmission, such as computer data, are interleaved with the voice packets
Over the last few years IPT gateways have experienced astounding growth and development. Businesses can expect to see enhanced applications that offer unified messaging, video, web-enabled call centers, and wireless.
Today's network architecture has to bridge the legacy PSTN with the IP network - essentially taking telephony traffic from existing PSTN switches and PBXs and converting it to packet-based transmission. In the future, IPT will evolve to complete, end-to-end packet-based transmission. Voice and fax traffic will originate and terminate in packet-switched devices such as IP Phones, Terminal Adapters (MTAs) and wireless devices.
This evolution will lay the foundation for integrated, high speed voice and data access for businesses, households, and consumers worldwide. It will also allow service providers and enterprises to manage their networks and add applications seamlessly through distributed, Web-based control tools. Services and applications, which today are controlled and configured using proprietary, difficult to manage PBX interfaces, will migrate to flexible, easy-to-use software based on open, industry standard protocols.
Clarent Corporation may be reached at 700 Chesapeake Drive, Redwood City, CA 94063; tel. 888-CLARENT; fax: 650-368-6330; email: agatha.chang@clarent.com; or visit www.clarent.com.