1. Chapter 1 Data Communications Industry

2. Objectives of Chapter 1 To understand the meaning of data communications To study the basic components of data communications as an industry To understand standards and regulations To have a general idea of the data communications industry challenges and solutions. GOAL: introduce you to the industry of data communications.

3. What is Data Communication Subset of Telecommunications. It is the encoded transmission of data via electrical, optical or wireless means between computer or network processors.

4. You will never know all there is to know about data communications

5. Data Communications Industry Forces that derive the data communication as an industry: The Regulatory Process The Standards Process Manufacturing, Research and Technology

6. Data Communications Industry Interacting components in data communication industry:

7. Figure 1-1 The Data Communications Industry: A Series of Interacting Components

8. Figure 1-2 Systems Relationship of Regulatory Agencies and Carriers The Regulatory Process

9. We must understand first the basic telecommunications infrastructure and the components of PSTN

10. Figure 1-3 Basic Telecommunications Infrastructure

11. Figure 1-4 Area Codes vs. LATAs

12. The Standards Process A Standard is an agreed upon protocol Thanks to standards users can be confident that devices will operate as specified and will interoperate successfully

13. Standardization Process 7 Steps to make standards: 1. Recognize the need for a standard 2. Formation of a committee 3. Information gathering 4. Tentative standards issued 5. Feedback on tentative standards is gathered 6. Final standards issued 7. Compliance with final standards

14. Organizations Standard making organizations are two categories Officially-sanctioned Ad-Hoc (task force, user group, interest group…etc.)

15. Organizations Usually vendor-initiated ad-hoc standard making organizations are organized into opposing camps with users left as victims between multiple standards for a single operation. Most often the development of a new technology precedes its standardization. Standardization process can be very political

16. Figure 1-8 Technology Development and Standards Creation

17. Confusion in standards Two issues can lead to confusion and might cause bad purchase decisions: 1. Standards Extension 2. The Jargon Jungle. “There is no data communications police”

18. Manufacturing, Research and Technology Supply and demand as driving forces of data communications. Technology push / Demand pull

19. Manufacturing, Research and Technology Technology should tie business demand for network services to carriers supply of these services: Business demand + available technology = emerging network services

20. Challenges and Solutions In the business of data communications there are lots of challenges. Network analyst must identify key challenges to succeed in data communication field We will address two challenges: Investment Vs. Productivity (Productivity Paradox) Data Compatibility

21. Investment Vs. Productivity Something is wrong with an analysis and design process which recommends technology implementation that fails to meet the strategic business objective of increased productivity. We need a structured methodology to insure that the network implemented actually meets the business objectives For this we introduce: The Top-Down Approach

22. Figure 1-10 The Top-Down Model

23. Benchmarking How can we measure the impact of the implemented network on the business process, in other words, how can we be sure that eventually the implemented network really meets the business requirements. We use Benchmarking: tying network cost to business value

24. Benchmarking Examine and document quantifiable improvements to business process Measure customer satisfaction, maybe by surveys Compare actual implementation cost with the cost of purchasing similar services from outside vendor (outsourcing), or examine other companies in the same market to compare cost.

25. Connectivity and Compatibility Compatibility: Bridging the communications gap between two or more technology components (HW or SW) This gap is referred to as Interface, it can be HW-to-HW or SW-to-SW or HW-to-SW.

26. Figure 1-12 Interfaces, Protocols, and Compatibility

27. Compatibility Compatibility is possible because we have Protocols A Protocol is a set of rules about how communicating components can talk to each other.

28. Protocols Protocols can be proprietary or open They can also be officially sanctioned or market driven (de facto) The sum of all protocols employed in a particular computer is referred to as “protocol stack”

29. Protocols The problem with protocols is that they are too many. How can a network analyst keep track of all the potential interfaces and their associated protocols. So, protocols must be organized in some kind of framework or most likely known as “communications architecture” Two of the most popular communications architecture are: the 7-layer OSI model and the 4- layer Internet Suite of Protocols (or TCP/IP) model

30. The OSI model Open Systems Interconnection It is neither a protocol nor a group of protocols. It is a standardized empty framework into which protocols can be listed to perform effective network analysis and design Each layer depends on previous layer to perform some function (transparency) Protocol Conversion

31. Consists of 7 layers that loosely group the functional requirements for communication between two computing devices. Each layer relies on lower layers to perform more elementary functions and to offer total transparency to the intricacies of those functions. At the same time, each layer provides the same transparent service to upper layers.

32. 1. Physical Layer: responsible for the establishment, maintenance, & termination of physical connection between communicating devices “Point-to-Point data link”. 2. Data-Link Layer: responsible for the providing protocols that deliver reliability to upper layers for Point- to-Point connections established by physical layer protocols. To allow the OSI model to closely adhere to the protocol structure, & operation of a LAN, Data-Link layer was splitted into two sublayers. OSI Model

33. Media Access Control (MAC): interfaces with the physical layer & is represented by protocols that define how the shared LAN media is to be accessed by the many connected computers. Logical Link Control (LLC): interfaces to the network layer. The advantage of splitting the Data-Link layer & of having a single common LLC protocol is that it offers transparency to the upper layers while allowing the MAC sublayers protocols to vary independently. Data-Link Sublayers

34. 3. Network Layer: responsible for the establishment, maintenance, & termination of end-to-end network links. Network layer protocols are required when computers that aren’t physically connected to the same LAN must communicate. 4. Transport Layer: responsible for providing reliability for the end-to-end network layer connections. It provide end-to-end recovery & flow control. It also, provide mechanisms for sequentially organizing network layer packets into a coherent message. OSI Model cont’d

35. 5. Session Layer: responsible for establishing, maintaining, & terminating sessions between user application programs. 6. Presentation Layer: provide an interface between user applications & various presentation-related services required by those applications. An example is data encryption/decryption protocols. 7. Application Layer: it includes utilities that support end- user application programs but it does not include end- user application programs. OSI Model cont’d

37. Internet Suite of Protocols Known as TCP/IP protocol suite or TCP/IP architecture TCP/IP: Transmission Control Protocol / Internet Protocol Like the OSI model but it has 4 layers

38. Figure 1-14 Internet Suite of Protocols vs. OSI

39. I-P-O Model Input – Processing – Output Ex. Connecting the computer (serial port) to the printer (parallel port) Identify and document the process you want to make on the input and what kind of output it should provide.

40. The Data Communications Profession – Professional Development What critical skills are required for data communications professionals. To know the skills you must know the environment in which they will work, which is a knowledge- based economy. Data Communications professionals are thought of today more as partners or change agents rather than consultants.

41. Required Skills 1. Speak the language of Business 2. Demonstrate the ability to solve business problems in a partnership role 3. Demonstrate the ability to look outside their own expertise for solutions 4. Understand the need for lifelong learning 5. Demonstrate the ability to evaluate technology as to cost/benefit 6. Understand comparative value and proper applications of available network services 7. Communicate effectively, both verbally and orally, with both technology oriented people and business management personnel

42. Figure 1-16 Critical Skills for Data Communications Professionals

43. Professional Certification Why seek certification? It is an indication of mastery of a particular vendor’s technology, that may be important in some employment situations The problem with certification: The amount of material required to earn a certificate The amount of continuing education and experience required to retain this certificate Vendor-specific certifications do not provide the broad background required for today’s multivendor internetworks