capabilities may reside on an applications server that is part of the softswitch network described earlier. In particular, by leveraging IP technology, the voice media stream is truly separated from the signaling path. Thus a premise- based applications server can easily direct calls over the public network without having the call come into the premises and back out again. Placing Calls From The Computer Database Many individuals in the workplace have a computer data- base that includes names, addresses, telephone numbers and other information about contacts. These programs enable you to dial out by using the computer mouse to point and click on the tele- phone number on the screen, rather than having to dial the telephone. This is a natural application for third-party call con- trol. The PC requests he communications server to place the call to the desired party as well as the user's telephone, and then con- nects them. See www.edial.com for an example of such a service. IP Telephony IP Telephony is the collective set of applications providing PBX type services in an IP telephony environment. This can mani- fest itself in three ways: a. The PBX as a piece of Customer Premise Equipment - the telephones are connected through the same network (using the same pair of wires) as the computers whether 168 85 The Telecom Handbook CHAPTER 7 it is a local area network or wide area network connect- ing multiple sites. Administration of the telephones (making program changes, running reports on usage, etc.) can be done through any computer on the network (pro- vided it is authorized to do so). b. IP Centrex pairs a new concept using an old term. Tele- phone service is provided using IP from an applications server not located on the users premises. The applica- tions server can be located anywhere and support the connection of multiple locations as if all were on the same premise. This concept is also known as an ASP (Applica- tion Service Provider). IP Centrex applications may emulate traditional ca- pabilities like "do not