CENG 3331 Introduction to Telecommunications and Networks

Ch. 1.1 Data Communications and Networking for Today’s Enterprise

Figure 1.1 Average Downstream Traffic per Internet Subscriber Figure 1.2 Past and Project Growth in Ethernet Data Rate Demand Compare to Existing Ethernet Data Rates Figure 1.3 Simplified Communications Model

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1.2 A Communication Model

How can a communications system be modeled?

– What are the components?

– What are the tasks?

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What is meant by data communications networking?

– What are WANS and LANs?

– What is circuit switching, packet switching, frame relay, and ATM?

What are network protocols and architectures?

1.2 A COMMUNICATIONS MODEL

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Fig.1-3 A Simplified Communications Model

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Components

– Source – Transmitter – Transmission system – Receiver – Destination

Communication Tasks

• Transmission System Utilization • Interfacing • Signal generation • Synchronization • Exchange management • Error Detection and Correction • Flow control • Addressing • Routing • Recovery • Message formatting • Security • Network management

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1.3 DATA COMMUNICATIONS Fig. 1.4 Simplified Data Communications Model

– 1 . Input information--m.

– 2. Input data--g(t) – 3. Transmitted data--s(t) – 4. Received Signal--r(t) – 5. Output data--g’(t) – 6. Output information--m’ •

Examples:

– Electronic mail--

discrete

information – Telephone conversation--

analog

information

1.4 Networks

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Wide-Area Networks

– Circuit Switching – Packet Switching – Frame Relay – ATM •

Local Area Networks (vs. WANs)

– 1. Smaller geographical “scope.” – 2. Owned by user organization.

– 3. Higher data rates are used.

• Wireless Networks

1.5 The Internet

• Figure 1.5 Key Elements of the Internet • Figure 1.6 Simplified View of Portion of Internet • Table 1.2 Internet Terminology (page 27)

1.6 An Example Configuration

• Figure 1.7 A Networking Configuration