Understanding The Advantages And Disadvantages Of

Abstract

This paper provides an outline to our Learning Team C's Project, Understanding the Advantage and Disadvantages of Voice over Internet Protocol (VoIP). This outline will cover the following areas: Provide a detail description of what is VoIP; Identify what technology is involved with VoIP; Provide future trends in VoIP; Provide example of companies involvement with VoIP; Identify regulatory issues surrounding VoIP; and identify any global implications of VoIP.

1. What Is Voice Over Internet Protocol (VoIP)

a. VoIP, or Voice over Internet Protocol, is a method for taking analog audio signals, like the kind you hear when you talk on the phone, and turning them into digital data that can be transmitted over the Internet. VoIP is a revolutionary technology that has the potential to completely rework the world's phone systems.

2. Technology Involved With VoIP

a. Once people realized that they could use a computer to send traditional telephone traffic over the Internet, there was no looking back. Voice over Internet Protocol (VoIP) got its start around 1995 when hobbyists started testing the concept (http://www.voipreview.org/news.details.aspx?nid=51). The VoIP industry didn't really start until 1998 when the first companies started offering PC to phone service thereby allowing a PC user to call a traditional landline telephone. AS time passed and larger companies like Cisco and Lucent started getting involved in the industry, in 2000 VoIP services accounted for 3% of the voice traffic (http://www.whichvoip.com/voip/articles/voip_history.htm). As these larger players came on board there was much discussion and development of competing technologies.

b. There are many varieties of VoIP. A VoIP calls consists of 2 parts. One part is the signaling that will control the call flow like sending a busy message or hanging up the call. Another part is the media, also known as RTP (Real Time Protocol), which is the actual voice part of the call. Each part has many ways to be implemented. While some manufacturers have tried to make their protocol the standard, most follow the guidelines of the IETF (Internet Engineering Task Force) and ITU (International Communications Union). The two prevalent signaling protocols today for consumer use are SIP (Session Initiation Protocol an IETF standard via RFC 3261) and H.323 (an ITU standard) which is constantly evolving. Most companies will use SIP to the consumer location and H.323 protocols for inter Telco (Telecommunication company) communication. As far as media goes, many codecs exists for conversion from analog to digital. These codecs determine the bandwidth and potentially the quality of the call. The codecs in use most today for consumers are G.729 and G.711 (http://www.globalcrossing.com/pdf/services/VoIPconsid_tech.pdf#search=%22%20voip%20most%20popular%20codecs%22). Other codecs that are quickly becoming widespread are Skype and iLBC (Internet Low Bitrate Codec). Also of note is the T.38 standard for sending faxes. As you can see there are many ways to send a so called VoIP call that most people do not think about.

c. VoIP technology is also used a many ways. We have already explored the consumer market which includes companies like Vonage and Skype. Businesses also use VoIP for interoffice and intraoffice communications. Many products exist on the market to handle this traffic. Two of the most popular are the Cisco Call Manager and the free Asterisk product Linux operating systems. The great thing about the products is that they run on normal computer systems and therefore can be provisioned and monitored by the companies IT department. Another use of VoIP includes communication between telcos. So the customer would place a call from their PSTN through their telco, the telco would convert the call to VoIP signaling and media to send to a vendor for termination. The vendor could receive the call and convert it back to PSTN to send to the dialed number. Once the call is established, part will be PSTN and part will be VoIP, but both ends may never know VoIP is being used.

d. Cisco Call Manager and Asterisk act like a gateways and can handle VoIP calls in a variety of formats. The two PBX systems can link various protocols including standard telephone lines like POTS and PSTN with VoIP protocols like SIP, MGCP, iLBC, SCCP, G.729, G.711, and H.323. These systems also handle traditional services such as voicemail, call waiting, and three-way calling.

e. VoIP technology still has some drawbacks to overcome. The main ones are voice quality and echo. The great news is that there are many companies trying to make it better in terms of quality, price, and integration abilities. You can already see that with the free products offered like GoogleTalk that offer free phone calls to standard phone lines. The future for VoIP and its associated technologies is bright indeed.

3. Future Trends with VoIP

a. Less than fifteen years ago, internet access was a service provided by our public switch telephone network (PSTN), and today the roles has be reversed; voice has become a service to the internet.

b. When VoIP was introduced to the market there were many obstacles that needed to be addressed. For years the world has used traditional phone lines to communicate with one another. The companies that owned and operated these phone lines have always provided a reliable service. The new VoIP companies would have to establish a reputation of providing the same reliable service.

c. As the VoIP companies began to become established in the market, a new obstacle arose. Consumers using VoIP services were not able to be located by 911 services. In May of 2005 the FCC ordered that all providers offering VoIP services have a solution that enabled a caller's location and telephone number is available for emergency reasons. If providers did not comply with this, they would have to stop offering services. Since then solutions have been developed for this functionality but are still not widely implemented.

d. As VoIP begins to become reliable and offer more advanced features, more and more consumers are signing up to take advantage of VoIP services. VoIP is offering consumers an inexpensive and reliable method of communication to people all over the world. Both businesses and personal homes are now frequently utilizing these services.

e. With the adoption of VoIP services increasing, many companies have started to offer these services. Cable companies are now offering a bundled package offering cable television, high speed internet and unlimited phone services all in one monthly bill. Many smaller