Digital Telephone Systems and VoIP
A Dedicated IP Phone for Any Broadband Line
A common question when people first enter the world of VoIP and digital telephony services is: What’s the difference between the VoIP service and digital phones? What’s an IP Phone? We’ll attempt to answer those questions here.
For generations a phone was connected to a dedicated ‘land line’ or telephone line. Essentially, a standard telephone line is a copper wire that runs into your house. This line, gathered with all the other lines from houses and businesses, formed a telecom network. That telecom network was owned by a giant phone company, e.g. AT&T. Several of these telephone companies had a monopoly on the market. Consequently, a bill passed by the United States Senate caused the breakup of these giant companies. While these companies were reorganizing their networks an unassuming network was quietly being rolled out to households across America: Cable television. Originally, Cable TV was intended for community access to an antenna for television reception. The advent of the Internet transformed these networks into something even more powerful.
Broadband and internet technologies mean it’s not so simple anymore. In most cases, the same copper wires now connect to a wide band fiber-optic network that could be owned by one of many companies.
Today, most city dwellers have at least two lines running into their households: a telephone line and a Cable TV line. Even if you don’t subscribe to Cable, chances are it’s there or the network exists in the neighborhood and can easily be added to the Cable Company’s grid. You have two high-speed (broadband) data service providers to choose from, cable and telephone. The two competing systems are referred to as Cable or DSL. Both are capable of providing digital or VoIP telephony services without the other service being present.
Digital Telephony Services: This is simply VoIP or Voice over IP. This specifically refers to the service where your voice, over either a PC or telephone, is transmitted digitally over the internet and is able to break into a phone company’s telecom service. This means you can use your digital service through the internet to ring someone’s telephone. Hence, digital telephony is a means of bridging two distinct networks: the high speed data transmission provided by Cable TV or your local phone company.
What Digital Telephony is Not: Digital telephony is not simply the act of sending your voice over the internet to someone else who is also using the internet at the same time. This service is performed by software like "Net Meeting." It’s more advanced than Instant Messaging in that your voice is often accompanied by a live video feed during communication. The parties who are communicating require a PC or another digital device, and both parties must be running the same or compatible software applications to allow for this.
Digital Telephony has nothing to do with using your regular analogue telephone through a standard phone service, even if you subscribe to DSL or have high-speed internet access. You must specifically subscribe to a VoIP service to use a digital phone or conduct digital-phone conversations.
Digital to Digital: Digital to digital telephone communications occur when both parties are using a broadband internet line to communicate from a digital network using VoIP. In this instance, it’s possible that the phone conversation may never be routed through a PSTN (Public Switched Telephone Network) and might occur completely through the internet. Since most of the VoIP services try to be completely seamless, you may never know if you’re communicating to another VoIP subscriber and breaking into the telecom network.
The confusion arises with the hardware involved with VoIP. There are three things needed to use VoIP. The first two things you will need are a telephone and a high-speed internet connection. The final requirement goes by many terms: a digital phone adaptor, VoIP gateway, or digital/analogue converter. This last requirement is not needed if you have what’s called an IP phone or a digital phone system.
Digital Phone Systems: Are simply a telephone like any other, but they’re capable of connecting to the internet and obtaining an IP address all by themselves. A true digital phone doesn’t require a gateway, a digital/analogue converter, or any of the other hardware you hear associated with VoIP. A serious, long-time VoIP user might be well advised to use an IP phone for its ease of use and convenience. Depending on your VoIP service, you can travel with your VoIP phone and connect it to any high-speed internet connection.
911: It should be noted that through a digital phone service you’re responsible for providing power to your telephone equipment even in the event of a power outage. For this reason, you must have some form of backup in place in case you need to make a call an emergency phone call.