IS 311 – IT IN BUSINESSVoice over Internet ProtocolRobert HegerDana NarteaAssaf MaozNovember 19, 2002VOICE OVER INTERNET PROTOCOLBackgroundInternet ModelThe Internet’s 5-Layer Model (top – down hierarchy)Application: used by application program - the start of the five - layer process.Transport: establishing end-to-end connections, translates domain names into numeric addresses, and segments messages (also known as the TCP layer)Data Link: deals with message delineation, error control & network accessPhysical: defines how information will be transmitted through the networkVoIP – How Does It WorkStandards InvolvedVoIP ApplicationsDisadvantages of VoIPConclusion – Expected Growth and Future of the VoIP TechnologyVoice over IPIS 311 – IT IN BUSINESSVoice over Internet ProtocolRobert HegerMichelle LeDana NarteaAssaf MaozNovember 19, 20020Voice over IPVOICE OVER INTERNET PROTOCOLBackgroundU.S. government agencies realized the importance and the potential of internet technology several years ago. The potential of internet technology was generously funded by the Advanced Research Projects Agency (ARPA) resulting in a global Internet. Part of the ARPA technology was to create a set of network standards that specify the details of how computers communicate as well as a set of conventions for interconnecting networks and routing traffic. Officially this standard is called TCP/IP and is the standard by which computers communicate across any set of interconnected networks, whether they are connected internally all within one network or connected through networks that span geographic distance. Therefore, TCP/IP is the base technology for the global Internet that connects over 170 million individuals in homes, schools, corporations and government labs in virtually all populated countries. The global Internet allows subscribers to share information with anyone around the world as easily as they share it in the next room. An outstanding success, the Internet demonstrates the viability of the TCP/IP technology and shows how it can accommodate a wide variety of underlying network technologies. Transmission control protocol and Internet protocol work differently making the feasibility of this standard to handle a wide variety of underlying networking needs possible. TCP is aconnection orientated circuit that gets established between two hosts and exchanges streams of data. TCP is considered a reliable protocol because it guarantees both the delivery of the data and the order of the packets that it is sending. However this connection requires constant bandwidth to maintain the connection. Internet protocol is a connection-less orientated circuit that works at the packet, also known as datagram level and is considered to be an unreliable protocol. IP specifies the format of packets and the addressing scheme. Most networks combine IP with the higher-level protocol TCP. Internet protocol is considered unreliable because it allows IP packets (datagrams) to be sent in any order and be received in any order. By utilizing this protocol, several individual packets can be sent and switched in bulk to their forward location. The true benefit of IP is that several types of information can be encapsulated with individual IP packets. For the purpose of this paper, we will look at the encapsulation of voice and their transmission using an IP packet. Internet Model The most common standard now for open connectivity amongst networks is the 5-layer Internet model. The Internet model provides a flow from the application level where it begins to the physical layer where information is sent in and out of the computer. The Internet model has standardized the assent and decent of a datagram in transmission. 1Voice over IPThe Internet’s 5-Layer Model (top – down hierarchy)• Application: used by application program - the start of the five - layer process. • Transport: establishing end-to-end connections, translates domain names into numeric addresses, and segments messages (also known as the TCP layer) - Network: responsible for end-to-end addressing and routing, determines destination address if unknown (also known as IP layer)• Data Link: deals with message delineation, error control & network access • Physical: defines how information will be transmitted through the network VoIP ConceptsThe Internet is once again changing the way people communicate through the use of Voice over Internet Protocol (VoIP) technology. Every month millions of people worldwide are discovering and harnessing the power of the Internet. According to Global Reach, as of March 2002, there were over 561 million Internet users in the world making VoIP more commonplace. Recently, according to the International Engineering Consortium (IEC), the Internet is composed of more than 130,000 networks worldwide.VoIP is the transmission of voice traffic in packets (Black, 1). In simple terms, it is the transmission of voice using IP. In some cases, two computer users who are logged onto the Internet will run a program that has VoIP capability. Depending on the VoIP application, a user may be required to input an IP address of the computer to which he or she wishes to connect. Other software may provide users with “Buddy Lists,” which show their contacts and whether they are online or not. Depending on the software, if a remote user on the buddy list is online, a user may simply select the user with whom he or she wishes to chat with and send them a request to chat (with most applications). When a buddy list is used, theIP address does not need to be known by the user because the IP was determined by the application itself. Some very common, and popular software, which either come standard with most Microsoft operating systems, with Internet Explorer, or are free to download and use, are the following:- Microsoft NetMeeting- MSN Messenger- ICQ- AOL Instant Messenger- Yahoo Messenger 2Voice over IPVocaltec Inc. was the first company to introduce VoIP in February of 1995 with their Internet Phone software. This initial software was developed for 486 Mhz machines with a sound card, speakers, microphone and a modem. The Internet Phone software simply compressed the voice signal into Internet Protocol (IP) packets and transmitted them across the Internet to another user. This transmission was between a PC and a PC, and would only function when both users were using the same software. People