Chapter 1

Data Communications Industry

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.

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.

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

Data Communications Industry

Forces that derive the data communication as an industry: The Regulatory Process The Standards Process Manufacturing, Research and Technology

Data Communications Industry

Interacting components in data communication industry:

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

Judicial Political / Legislative

Standards making organizations

Vendors / Consultants

Technology / Research

Carriers

Regulatory Agencies

Manufacturers

Data communications

Residential customers

Business customers

GOLDMAN & RAWLES: ADC3e FIG. 01-01

Internet Service Providers

Figure 1-2 Systems Relationship of Regulatory Agencies and Carriers

Carriers Regulatory agencies

Proposals

Rulings

GOLDMAN & RAWLES: ADC3e FIG. 01-02

The Regulatory Process

The Regulatory Process

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

Figure 1-3 Basic Telecommunications Infrastructure

Phone Local loopC.O.

P.O.P.

Phone

C.O.P.O.P.

Local loop

Inter-exchange circuit

Belongs to IXC (Inter-eXchange Carrier)

Belongs to LEC (Local-Exchange Carrier)

LATA - A

LATA - B

GOLDMAN & RAWLES: ADC3e FIG. 01-03

Figure 1-4 Area Codes vs. LATAs

Indianapolis

Evansville

South Bend

Attica

Terre Haute

Rising Sun

GaryMichigan City

New Albany

Fort Wayne

Richmond

West Lafayette

Area Code Map LATA Map

Columbus

(219)

(317)

(812)

Indianapolis

Evansville

South Bend

Attica

Terre Haute

Rising Sun

GaryMichigan City

New Albany

Fort Wayne

Richmond

West Lafayette

Columbus

(765)

GOLDMAN & RAWLES: ADC3e FIG. 01-04

Russiaville Russiaville

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

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

Organizations

Standard making organizations are two categories

Officially-sanctioned Ad-Hoc (task force, user group, interest

group…etc.)

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

Figure 1-8 Technology Development and Standards Creation

lopment

Time

Le

vel o

f d

eve

lop

me

nt

Ready for market introduction

Introduction of first generation technology

Standards making lag time

Standards finalized Introduction of second generation technology

GOLDMAN & RAWLES: ADC3e FIG. 01-08

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”

Manufacturing, Research and Technology

Supply and demand as driving forces of data communications.

Technology push / Demand pull

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

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

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

Figure 1-10 The Top-Down Model

BUSINESS

RE

QU

IRE

ME

NT

S

SO

LU

TIO

NS

APPLICATION

DATA

NETWORK

TECHNOLOGY

GOLDMAN & RAWLES: ADC3e FIG. 01-10

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

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.

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.

Figure 1-12 Interfaces, Protocols, and Compatibility

NOS Driver Software - Windows

using NDIS communication

Ethernet 10 Base-T Network Interface

Card (NIC)NDIS

Serial portSerial cable

DB-25

Hardware to Hardware Interface

Physical interface: Serial cable to serial port

Mutually supported protocol: DB-25

Software to Hardware Interface

Interface: Network Operating System (NOS) driver to Network Interface Card (NIC)

Mutually supported protocol: Network Driver Interface Specification (NDIS)

NDIS

Software to Software Interface

'91 '92 '93 '94 '95 '96

100

200

300

400

500

600

yearspr

ofits

(in

mill

ions

)

EXCEL.XLS WORD.DOC

OLE

'91 '92 '93 '94 '95 '96

100

200

300

400

500

600

years

prof

its (

in m

illio

ns)

Six Year Profits

This graph depicts the Company's growth over the past 6 years. We have experienced massive gains in every corporate category.

Implementing mutually supported protocols allows interfacing hardware and/or software technology to communicate, thereby insuring compatibility.

Incorporate a Microsoft Excel graphic within a Microsoft Word document.

The serial cable is compatible with the serial port.

Software interface: EXCEL to WORD

Mutually supported protocol: OLE2 (Object Linking and Embedding)

GOLDMAN & RAWLES: ADC3e FIG. 01-12

Compatibility

Compatibility is possible because we have Protocols

A Protocol is a set of rules about how communicating components can talk to each other.

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”

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

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

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

Figure 1-14 Internet Suite of Protocols vs. OSI

1

2

3

4

Physical

5

6

7

Data Link

Network

Transport

Session

Presentation

Application

Application

Transport or

Host-Host

Internet

Network Access

Transport Protocol Packets

IP Diagrams

Frames

Messages or

Streams

TELNET FTP

TFTP SMTP SNMP CMOT MIB

TCP UDP

IP

Layer OSI INTERNET ProtocolsData Format

GOLDMAN & RAWLES: ADC3e FIG. 01-14

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.

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.

Required Skills

1. Speak the language of Business2. Demonstrate the ability to solve business problems in a

partnership role3. Demonstrate the ability to look outside their own expertise for

solutions4. Understand the need for lifelong learning5. Demonstrate the ability to evaluate technology as to cost/benefit6. Understand comparative value and proper applications of

available network services7. Communicate effectively, both verbally and orally, with both

technology oriented people and business management personnel

Figure 1-16 Critical Skills for Data Communications Professionals

Technological skills

Communication and

understanding

Interpersonal skills

Business knowledge

Data communications

professionalsCommunication and

understandingCommunication and

understanding

GOLDMAN & RAWLES: ADC3e FIG. 01-16

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