VoIP can facilitate tasks and provide services that may be more difficult to implement or expensive using the more traditional PSTN. Examples include:

• The ability to originate phone calls by clicking a phone number on your computer display. Receiving FAX messages as emails instead of using paper, toner, and electricity to print them (and the convenience of receiving the FAX when not in the office).
• The ability to transmit more than one telephone call down the same broadband-connected telephone line. This can make VoIP a simple way to add an extra telephone line to a home or office.
• 3-way calling, call forwarding, automatic redial, and caller ID; features that traditional telecommunication companies (telcos) normally charge extra for.
• Secure calls using standardized protocols (such as Secure Real-time Transport Protocol.) Most of the difficulties of creating a secure phone over traditional phone lines, like digitizing and digital transmission are already in place with VoIP. It is only necessary to encrypt and authenticate the existing data stream.
• Location independence. Only an internet connection is needed to get a connection to a VoIP provider. For instance, call center agents using VoIP phones can work from anywhere with a sufficiently fast and stable Internet connection.
• Integration with other services available over the Internet, including video conversation, message or data file exchange in parallel with the conversation, audio conferencing, managing address books, and passing information about whether others (e.g. friends or colleagues) are available online to interested parties.

A Network Sketch

Your network sketch doesn't need to be anything fancy; a simple diagram on a sheet of paper is fine. Your main goal is to be able to visualize your system and to select proper equipment and locations for your phone system.

Use symbols to map out your devices. You can use the diagram I have included as a guide for symbols and formatting, or make up your own ( Figure 3.1 ). You are the only one who needs to be able to understand your map.

Figure 3.1 A basic network diagram showing the orientation of network devices

Filling in Vital Statistics

As you complete your drawing, fill in details such as Internet connection bandwidth and location of devices ( Figure 3.2 ). You will use this information in your evaluation of your readiness for VoIP.

Figure 3.2 The network diagram with location and bandwidth information added

It is a good idea to test your bandwidth in addition to knowing what you are supposed to have. Almost all Internet connections perform at somewhat less than the speed advertised. You can test your bandwidth at a bandwidth site such as www.bandwidthplace.com or www.dslreports.com/stest.

Let's look at the phones

You might only have a single phone that you will be using with your service. If so, great! If you would like to connect more than one phone to your Internet phone system, take a quick look at your current configuration.

Mapping out your phone system is also important to your planning effort ( Figure 3.3 ). You should have a clear picture of how you plan to connect any existing phones you have to your new telephone adapter. As you map your system, note the location of each phone jack.