While theoretically not absolutely necessary, a broadband Internet connection is what makes your Internet phone calls reliable and understandable. VoIP uses a traffic engineering term called Quality of Service (QoS) that refers to the implementation of controls to ensure that delay sensitive IP packets are prioritized as they flow through the pipe. To forgo these controls would result in acoustic problems like jitter and echo, as well as dropped calls. Because a broadband pipe is much larger than a dial up connection, there is much more throughput capacity, or space, to allow us to prioritize.

There are basically three ways for the residential consumer to obtain a broadband Internet connection – from your cable television provider, your telephone company, or a wireless network. With these options becoming increasingly wider spread, utilizing the Internet to route your phone calls has also become a viable and cost saving alternative to traditional landline telephony. Now the question becomes, which type of broadband service is best suited for voice over IP telephony.

The Cable Broadband Connection

Since the advent of cable television, cable companies have contributed enormously to the development of the worlds Wide Area Networks (WAN), adding broadband Internet to their list of services offered. Indeed, with the development of VoIP, they have blurred the lines of the telecommunications Industry. The coax cable linking the household to a fiber optic trunk has ushered the Internet into the Jet Age with Internet service at the speed of light.

A cable company WAN consists of neighborhoods connected to nodes, each node having its allotted amount of bandwidth. The coax pipe is about the largest to be had for the residential consumer, and is plenty big enough for the clearest of VoIP phone calls. However, the bigger the neighborhood grows, and the more people that connect to the pipe, the less bandwidth is available for each household. Cable companies are generally good about distributing bandwidth and will add more nodes when necessary. Their network is, after all, their bread and butter. Just be aware that at peak traffic times, VoIP call quality can degrade.

Digital Subscriber Lines

The Digital Subscriber Line (DSL) is the residential broadband solution offered by traditional telephone companies like AT&T, the regional bells and others. For years the Telco’s have had the upper hand in the business community, connecting their networks to the outside world via a T1 line, which is the equivalent bandwidth wise to a cable modem.. DSL is somewhat slower than a cable broadband, and in fact, in some communities is offered at 2 speeds. It also tends to be cheaper. Nevertheless, there is still ample bandwidth to implement VoIP successfully.

DSL is not affected by node saturation like cable networks, but it is distance sensitive. The further you are from your telephone company’s switching station the more signal degradation you will have, the maximum distance being 18,000 feet. Telco’s can and do use remote switching stations to expand their service where they see a market opportunity.

The fatal flaw of DSL when considering the use of VoIP, is that most companies require you to subscribe to their traditional telephone service as well. Naked DSL, the unbundling of broadband and telephone service is possible, but is offered by only a few local phone companies. Perhaps because of the competition from cellular and the cable companies creeping onto their turf, the Telcos need to get the revenue where they can.

In January ’07, the Senate reintroduced the Internet Freedom Preservation Act. One of the provisions called for is that all broadband service providers offer consumers standalone broadband service. If this Net Neutrality bill passes, DSL could prove to be a viable option for those wishing to switch to VoIP as their primary phone service.

The Wireless Networks

Wireless networks also provide ample bandwidth for VoIP telephony, and their value is most appreciated in the life of the Road Warrior. People who constantly travel, weather for business or pleasure, are finding Wi-Fi hotspots popping up everywhere. Most modern hotels have their own wireless network, and Internet cafes are becoming an international phenomenon. Travelers that find a hotspot have the choice of using their laptop and a headset to communicate over the Internet, or to use one of the many Internet Phones found on the market today.

If you’ve visited a college campus recently, you may have noticed tiny antennas sticking up from the rooftops every few meters. Campuses today have their own Wi-Fi mesh networks, connecting numerous wireless access points at appropriate distances, that allow students, faculty and administrators to transfer data and make VoIP phone calls via their laptop, or an Internet phone, from anywhere on campus. Wi-Fi mesh networks have also been implemented by law enforcement in urban areas to link patrol cars to their database at the central station. Just now emerging is a new technology calledWiMAX that is proving to be much better suited for situations like these.

Wireless Internet service providers (WISP) are just now beginning to proliferate worldwide. The emerging technology known as WiMAX is proving much cheaper to implement than a traditional wireline network, bringing broadband access and VoIP to underdeveloped areas around the world. Like the cellular networks, one base station can cover about a three mile radius. Base stations with backhauls to a fiber optic backbone can be daisy chained to form a Metropolitan Area Network (MAN), providing high speed voice, video, and data to a large city and its suburbs.

Clearwire Wireless is a company that has pioneered WiMAX with its proprietary technology to cover cities and suburbs, even whole regions of the U.S and other countries. Clearwire and Sprint Nextel currently own most of the spectrum available for WiMAX technology in the U.S..

For the Cellular Networks in particular, WiMAX is a disruptive technology. The broadband pipe is much better suited for data, video, and voice than their current technologies, and with the rollout of Mobile WiMAX expected in 2008, faster handoffs between base stations are expected to make the technology a formidable competitor in the cell phone industry. While most of the Celcos in the US are continuing on their own path, Sprint Nextel owns the largest share of the spectrum by far, and is building its next generation 4G network based on WiMAX technology.

After Finding the Right Broadband Connection

Once the broadband pipe has been decided upon, there is still the issue of picking a VoIP service provider. Cable companies, Telco’s, and increasingly cellular companies all offer their own VoIP service to consumers, and since their service is over their own networks, they are in an excellent position to deal with Quality of Service issues.

You are not, however, under any obligation to use your broadband service provider as your VoIP service provider. Pure play VoIP providers, companies that offer only VoIP service, have grown in number, and could be said to be responsible for the low rates associated with VoIP telephony. Vonage, with around 53% of the residential VoIP market, is one pioneer in the industry that offers calling plans as low as $15 a month. SunRocket, Packet8, and the peer to peer VoIP company Skype, have calling plans for even less. Cable and Telco plans on the other hand, are bound to cost more, starting at around $35 or $40.

Whatever VoIP service provider you choose, and for whatever reason, the most important factor in determining the quality of the call is the quality of the pipe. Test your broadband connection for VoIP suitability at http://www.testyourvoip.com .

revised 6/2/07