All systems begin with the basic ability to send and receive local and long-distance calls world wide. Common features include call waiting, call forwarding, remote access, and caller ID. For business applications, phones must offer more. Perhaps one of the most useful features is the auto-attendant. When customers call in, they hear an automated menu of options. This may include instructions to press particular numbers to reach divisions within the business (press 1 to reach sales, press 2…etc.). Menus can be set up to automatically change after regular hours and on the weekends.

To avoid customers feeling as if they have been dropped into space while on hold, most systems have music on hold features. More sophisticated systems can allow different types of music to be programmed for different types of customers.

When the call is moved from the switch board to an employee, other features are important. The system should provide unlimited extensions. Each extension should have a message created by the employee that comes on when there is no one available to answer the phone. As well, there should be a means of identifying callers (caller ID), saving messages (voice mail), forwarding calls when the employee is at another desk, and sending calls when the employee is out of the office. Of particular value is the “hot desk” feature. This allows employees to move from desk to desk, taking their calls and voice mail with them.

To handle both voice and data transmissions, phone systems must have dedicated lines for each. A voice T1 system allows for 24 channels per phone line with 24 separate numbers. T1s are also used for Internet access. Internet download and upload speeds vary depending on the equipment used. Integrated T1 systems carry both voice and data on one line. VoiP (Voice over Internet Protocols) is a system for using the Internet to carry phone calls. There are a number of advantages to VoiP, including the ability to plug into the internet and make free calls from anywhere in the world.

It is essential that the phone system be able to handle conference calls. The proper phone bridge permits an unlimited number of internal participants and as many external callers as there are phone lines. Some systems even have the capability for handling unlimited external callers. With video conferencing more popular, phone lines can be used to carry both voice and video images.

There are many different systems available, and each one of them offer its own array of features especially suited for today's companies. Most can be easily upgraded with new components.