Introduction
After watching the 1975 film Three Days of the Condor the other night, it was interesting to see the main character Joe Turner (played by Robert Redford) utilize a telephone test set to listen in on a phone call. You can see this in the picture below. After serving in the United States Army Signal Corps as a phone maintenance specialist, Turner graduated from the City College of New York before going onto Bell Labs and the CIA. He’s a computer geek who would not feel out of place in today’s Silicon Valley.
Here’s an explanation of the tool being used. When connected to a line using the 2 leads, a test set is essentially indistinguishable from regular subscriber equipment. It can perform the following: monitor an active call, answer incoming calls, and make outgoing calls.
The great thing about such movies is it makes you think about the skills needed in computer science, information technology and electrical engineering to troubleshoot issues and solve problems.
Traditional Analog Phone Lines
Many people believe telephone wiring is difficult to do by themselves. Actually, the way it works is rather simple if you’re familiar with the ways electrical signals work over copper wire. All you need is 2 pairs of wires - one is called the Tip and the other Ring which complete the telephone circuit. In terms of polarity, Tip (+) is the nickname for the electrically positive wire and Ring (-) is the nickname for the electrically negative wire. Tip is the Green wire and Ring is the Red wire in a 4 conductor wire seen in an RJ-11 cable.
Modern Phone Systems (VoIP)
Today our options to call someone in another state or even another country are easier and more affordable than ever before.
- SIP providers such as Voip.ms are a low cost alternative to paying for a traditional phone line.
- Also with software such as Zoiper supporting any VoIP service provider, you can receive calls to your number from anywhere in the world. It is a Unified VoIP communications solution which handles Audio, Video, Fax, Presence and Instant Messaging.