Abstract
This paper provides an outline to our Learning Team Cs 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 worlds 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 didnt 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
