• No results found

MULTIMEDIA APPLICATION DEVELOPMENT Unit 1 Multicast

Fluckiger. (1994). Understanding Networked Multimedia, Prentice Hall

Sloane, (2002). Multimedia Communication, McGraw Hill.

(ISBN 0-077092228)

J. Vince, (1995).Virtual Reality Systems, Addison Wesley, (ISBN 0-201-87687-6)

Vaughan, Tay, 1998, Multimedia: Making It Work (fourth edition), Osborne/

McGraw-Hill, Berkeley.

Shuman, J. G. (2002). Multimedia Elements. Multimedia In Action. Vikas Publishing House Pvt Ltd.

Watkinson, (2004). The Art of Digital Audio, -Heinmann. Synthesizer Basics, GPI Publications.

MODULE 4 MULTIMEDIA APPLICATION DEVELOPMENT

6.0 Tutor Marked Assignment 7.0 References/Further Readings

1.0 INTRODUCTION

In this unit, we will learn the basics about Multicast process in the transfer of Information and then go on to study about some other Multimedia protocols in the Multimedia System.

2.0 OBJECTIVES

What you would study in this unit, would enable you:

• Explain what a Multicast is

• Understand the Mbone Concept.

• Identify the major characteristics of an Mbone

3.0 MAIN CONTENT 3.1 MULTICAST

In computer networking, multicast is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from source and creating copies automatically in other network elements, such as routers.

Multicast is most commonly implemented in IP multicast, which is often employed in Internet Protocol (IP) applications of streaming media and Internet television. In IP multicast the implementation of the multicast concept occurs at the IP routing level, where routers create optimal distribution paths for datagram sent to a multicast destination address.

In multicast communication, there is one source and a group of destinations. The relationship is one-to-may. In this type of communication, the source address is a unicast address, but the destination address is a group address, which defines one or more destinations. The group address identifies the members of the group.

A multicast packet starts from the source S1 and goes to all destinations that belong to group G1. In multicasting, when a router receives a packet, it may forward it through several of its interfaces.

At the Data Link Layer, multicast describes one-to-many distribution such as Ethernet multicast addressing, Asynchronous Transfer Mode (ATM) point-to-multipoint virtual circuits (P2MP) or Infini band multicast.

3.1.1 MULTICAST APPLICATION

Multicasting has many applications today such as access to distributed databases, information dissemination, teleconferencing and distance learning

Access to Distributed Databases

Most of the large databases today are distributed. That is, the information is stored in more than one location, usually at the time of production. The user who needs to have access to the database does not need to know the location of the information. The user’s request is multicast to all the database locations, and the location that has the information responds Information Dissemination

Businesses often need to send information to their customers. If the nature of information is the same for everyone, the information can be multicast. For example, a software update can be sent to all purchasers of a particular software package.

Dissemination of News

In a similar manner, news can be easily disseminated through multicasting. One single message can be sent to those interested in a particular topic. For example, the statistics of the championship of a college tournament can be sent to the sports editor s of many newspapers.

Teleconferencing

Teleconferencing involves multicasting. The individuals attending a teleconference all need to receive the same information at the same time. Temporary or permanent groups can be formed for this purpose.

Distance Learning

One growing area in the use of multicasting is distance learning. Lessons taught by one single professor can be received by a specific group of students. This is especially convenient for those students who find it difficult to attend classes on campus.

3.2 MBONE

Mbone (short for "multicast backbone") is a virtual network invented by Van Jacobson. The purpose of “Mbone” is to minimize the amount of data required for multipoint audio/video-conferencing. Since most Internet routers have IP multicast disabled due to concerns of bandwidth tracking and billing, the Mbone evolved to connect multicast-capable networks over the existing Internet infrastructure. The commercialization of multicast routers is difficult because there are no efficient access control capabilities to the multicast trees (multicast routers and their protocols), and because Internet service providers have difficulty computing charges for multicast traffic.

Some of its major characteristics are

Topology: combination of mesh and star networks

IP addresses: 224.2.0.0; routing schemes: DVMRP, MOSPF Session registration: IGMP

Mbone uses a network of Mrouters that can support IP multicast, and enables access to real-time interactive mulreal-timedia on the Internet.

SELF ASSESSMENT EXERCISE

Give a concise description of the term ‘Multicast’

__________________________________________________________

__________________________________________________________

__________________________________________________________

4.0 CONCLUSION

In this unit, we learnt that multicast is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from source and creating copies automatically in other network elements.

5.0 SUMMARY

In multicast communication, there is one source and a group of destinations. The relationship is one-to-may. In this type of communication, the source address is a unicast address, but the

destination address is a group address, which defines one or more destinations. The group address identifies the members of the group.

6.0 TUTOR MARKED ASSIGNMENT

1).Describe the basic characteristics of an Mbone?

2) What is multicasting?

3) List and describe the different aspects of multicasting

REFERENCES/FURTHER READINGS

Ash, Gerald (1997). Dynamic Routing in Telecommunication Networks. McGraw-Hill.

ISBN 0070064148.

Doyle, Jeff and Carroll, Jennifer (2005). Routing TCP/IP, Volume I, Second Ed..

Cisco Press. ISBN 1587052024.Ciscopress ISBN 1-58705-202-4

Doyle, Jeff and Carroll, Jennifer (2001). Routing TCP/IP, Volume II,. Cisco Press.

ISBN 1578700892.Ciscopress ISBN 1-57870-089-2

Huitema, Christian (2000). Routing in the Internet, Second Ed.. Prentice-Hall.

ISBN 0321227352.

Kurose, James E. and Ross, Keith W. (2004). Computer Networking, Third Ed..

Benjamin/Cummings. ISBN 0321227352.

Medhi, Deepankar and Ramasamy, Karthikeyan (2007). Network Routing: Algorithms, Protocols, and Architectures. Morgan Kaufmann. ISBN 0120885883.

UNIT 2 ROUTING