Telecom Network management

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EEE 582

Telecom Network management

Introduction

Instructors: Vikas Singh

Scope and Objective


Scope and Objective of the course


The course covers


management principles,


practices and technologies for managing telecommunication
and computer communication networks and services.


Discuss both theoretical and practical aspects of network
management.


SNMP
-
based protocols


TMN standards.


Network monitoring tools and systems.


RMON


web
-
based management.


Assignments

2

Vikas Singh, CSIS Dept. BITS Pilani

Text books and Reference


Text book


Mani Subramanian,
Network Management: Principles
and Practice
, Addison
-
Wesley, 2000.


Reference Books


Sallings, W.,
SNMP, SNMPv2, SNMPv3, and RMON 1
and 2
, Reading, MA: Addison
-
Wesley, 1998.


Divakara K. Udupa,
TMN Telecommunications
Management Network
, McGraw
-
Hill Professional Pub.,
1999

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Vikas Singh, CSIS Dept. BITS Pilani

Course Plan

Contd…



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Vikas Singh, CSIS Dept. BITS Pilani

Evaluation Scheme

Component

Duration

Weight

Test I

50 minutes.

20%

Test II

50 minutes.

20%

Assignments (Problem
solving, reading
assignments and Lab
work)

Regular

20%

Compre

3 Hrs.

40%

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Vikas Singh, CSIS Dept. BITS Pilani

Chapter 1

Data Communications

and

NM Overview

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Vikas Singh, CSIS Dept. BITS Pilani

Question


What is a network?


What is Network Management?


Why do we need Network Management?


What is the goal of network management?


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Vikas Singh, CSIS Dept. BITS Pilani

Network Management

What is it?


People and processes that coordinate and
plan

• Tools that assist in Reporting, Trouble
shooting, and Performance Analysis

• Applications that support a Network Services
Group in getting its job done


Why Network management?


• To keep network up and running

• Identify problems before they take the network
down.

• Minimize system downtime, thus increasing
productivity


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Vikas Singh, CSIS Dept. BITS Pilani

Goal of network Management


Goal of an NMS system is to ensure
that the users of network receive the
services with the quality of service they
expect


With minimum service interruptions

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Vikas Singh, CSIS Dept. BITS Pilani

Why use standards?


Without standards,


Network Management Systems from different
vendors would not be able to work together
without additional effort and integration


One is locked to a single vendor



Allows interoperability of Network
Management Systems from different vendors
of different network elements



Not restricted to single vendor for
compatibility and interoperability


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Vikas Singh, CSIS Dept. BITS Pilani

Outline

Chapter 1



Analogy of telephone network (section 1.1)



Data and telecommunication network (1.2)



Distributed computing environment (1.3)



Internet and TCP/IP based Networks (1.4)



Protocols and standards (1.5)



IT management(1.7)


Network management Goals , organization and Functions (1.8)



Network and system management (1.9)



Current status and future of network management 1.10

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Vikas Singh, CSIS Dept. BITS Pilani

Telephone Network

Chapter 1



Characteristics:



Reliable
-

does what is expected of it



Dependable
-

always there when you need


it



Good quality (connection)
-

hearing each


other well



Reasons:



Good planning, design, and
implementation



Good operation and management of


network

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Vikas Singh, CSIS Dept. BITS Pilani



Notice the hierarchy
of switches



Primary and
secondary routes
programmed



Automatic routing



Where is the most
likely failure?



Use of Operations
Systems to ensure
QoS

Telephone Network Model (1.1)

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Vikas Singh, CSIS Dept. BITS Pilani






Operations Systems / NOC



Monitor telephone network parameters



S/N ratio, transmission loss, call blockage, etc.



Real
-
time management of network



Trunk (logical entity between switches) maintenance


system measures loss and S/N. Trunks not meeting


QoS are removed before customer notices poor


quality



Traffic measurement systems measure call blockage.


Additional switch planned to keep the call blockage


below acceptable level



Operations systems are distributed at central offices



Network management done centrally from Network


Operations Center (NOC)

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Vikas Singh, CSIS Dept. BITS Pilani

Information Transmission


May be transmitted as:


Circuit switched mode


Message switched mode


Packet switched mode

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Vikas Singh, CSIS Dept. BITS Pilani

Communication Network

Network Communications

Tele
-
communication
network

Typically Circuit switched

Used for voice telecommunication

Also provide other services such as high
speed dedicated transmission

Such as E1 in India and higher


Data Communication
network

Typically Packet switched

Used for data transmission

May provide connection less or
connection oriented services

May also provide VOIP


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Vikas Singh, CSIS Dept. BITS Pilani



Data and Telecommunication Network (1.2)



Computer data is carried over long distance by telephone
(telecommunication network)



Output of telephone is analog and output of

Computers is digital



Modem is used to “modulate” and “demodulate”


computer data to analog format and back



Clear distinction between the two networks is


getting fuzzier with modern multimedia networks

PSTN

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Vikas Singh, CSIS Dept. BITS Pilani

IBM SNA Architecture



IBM System Network Architecture (SNA) is a major


step in network architecture



SNA is based on multitude of (dumb) terminals


accessing a mainframe host at a remote location


SNA architecture is a centralized architecture, and not used any more

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Vikas Singh, CSIS Dept. BITS Pilani

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Vikas Singh, CSIS Dept. BITS Pilani



DCE with LAN (section 1.3)

DCE.. Distributed Computing Environment



Driving technologies for DCE:



Desktop processor



LAN



LAN
-

WAN network


Questions: Why we need a LAN?


What are the advantages of a LAN network


What are the different networks you are familiar with?


Inter
-
LAN connectivity ?

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Vikas Singh, CSIS Dept. BITS Pilani

Notes





Major impacts of DCE:



No more monopolistic service provider



No centralized IT controller



Hosts doing specialized function



Client/Server architecture formed the core


of DCE network

LAN
-
WAN Network


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Vikas Singh, CSIS Dept. BITS Pilani



Post office analogy; clerk the server, and the


customer the client



Client always initiates requests



Server always responds



Notice that control is handed over to the receiving


entity.


What other analogies can you think of ?

Request

Response

Client/Server Model

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Vikas Singh, CSIS Dept. BITS Pilani



Client/Server Examples

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Vikas Singh, CSIS Dept. BITS Pilani

Internet and Protocols


What is Internet


A network of networks


Public networks peering with each other and
interconnected with each other


Each Network operating independently


A distributed Network


Uses packet switching


Based on TCP/IP protocols


Uses connection less network protocol for routing


Common applications: HTTP (Web browser), SMTP
(Simple mail transfer protocol) and FTP

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Vikas Singh, CSIS Dept. BITS Pilani

Internet Architecture

FTP

SMTP

TELNET

HTTP

TCP

UDP

IP ICMP

ARP & RARP

Ethernet

X.25

PPP

PMPP

Application

Transport

Network

Link Level

SNMP

Others

Voice

Over IP

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Vikas Singh, CSIS Dept. BITS Pilani

Internet Protocol Layers

APPLICATION

PRESENTATION

SESSION

TRANSPORT

NET

INTER

INTRA

DATA LINK

PHYSICAL

APPLICATION

FTP ,SMTP,

Telnet, HTTP, SNMP


TCP: Transport



IP: Internet Protocol

IEEE 802

X.25

HARDWARE

TCP/IP AND OSI: Functional Positioning of Layers

ISO/OSI Layered Model


for data communications

TCP/IP Model for

data communications

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Vikas Singh, CSIS Dept. BITS Pilani

TCP/IP Based Networks



TCP/IP is a suite of protocols



Internet is based on TCP/IP



IP is Internet protocol at the network layer level



TCP is connection
-
oriented transport protocol and ensures
end
-
to
-
end connection



UDP is connectionless transport protocol and provides
datagram service



Internet e
-
mail and much of the network mgmt.


messages are based on UDP/IP



ICMP part of TCP/IP suite. An example of


SNMP is application layer protocol


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Vikas Singh, CSIS Dept. BITS Pilani



Internet Configuration


LAN A

LAN B

LAN C

Bridge /

Router

Bridge /

Router

Bridge /

Router

LAN Y

LAN Z

LAN X

Bridge /

Router

Bridge /

Router

Bridge /

Router

Internet

Workstation

Mail Server

Figure 1.9 Internet Configuration

Mail Server

Workstation

Gateway

Gateway

Domain

Name

Server

Workstation

(Joe)

PC (Sally)

Private TCP/IP

Network

Also called

Intranet

Private
TCP/IP

Network

Also called

Intranet

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Vikas Singh, CSIS Dept. BITS Pilani

Internet Configuration


Domain

Name server

LAN B

LAN A

Mail

Server

B/R

B/R

B/R


LAN C


Gateway1

Internet

Gateway


LAN abc


B/R

B/R


LAN x


Mail

Server


Asha’s

Workstation

Anand’s

workstation

Asha’s email:
Asha@b
its
-
pilani.ac.in

Anand@dest.com

Intranet

Domain name:

bits
-
pilani.ac.in

Internet consists of
multiple domains

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Vikas Singh, CSIS Dept. BITS Pilani

Notes


Gateway: The Intranet or local network may have a
different set of protocols running as compared to Internet.
As an example the client network might be using Novell
LAN, which uses XNS protocol. Gateway 1 will provide
protocol translation from XNS to TCP/IP

30

Vikas Singh, CSIS Dept. BITS Pilani

Autonomous Systems

Internet Routing Architecture

R

R

R

R

R

Autonomous System A

Stub AS

Autonomous System B

R

R

R

Autonomous System C

R

R

R

R

Autonomous System D

Multi
-
homed AS

R

Border Router: also called gateway router

R

Interior Router

(Transit AS for AS B)

R

R

R

R

R

R

R

R

R

R

R

R

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Vikas Singh, CSIS Dept. BITS Pilani



Architecture, Protocols and Standards



Communication architecture



Modeling of communication systems, comprising



functional components and



relationship between those components


Defined by operations interfaces between them



Communication protocols



Operational procedures



intra
-

and inter
-
modules



Communication standards



Agreement between manufacturers on protocols


of communication equipment on



physical characteristics and



operational procedures



Questions: Examples of protocols?


Why do we need Protocols?


Why do we need standards?

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Vikas Singh, CSIS Dept. BITS Pilani



Communication Architecture



Inter
-
layer interface: user and service provider



Peer
-
layer protocol interface



Analogy of hearing
-
impaired student (protocol conversion)



Role of intermediate systems



Gateway: Router with protocol conversion as


gateway to an autonomous network or subnet

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Vikas Singh, CSIS Dept. BITS Pilani




Importance of the knowledge of layer structure in NM


OSI Reference Model

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Vikas Singh, CSIS Dept. BITS Pilani




OSI Layers and Services



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Vikas Singh, CSIS Dept. BITS Pilani

PDU Communication Model



What is the relevance of PDU model in NM?

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Vikas Singh, CSIS Dept. BITS Pilani



cc:mail from a station in Novel IPX network to an Internet
station with SMTP e
-
mail

1
-
21

Gateway Communications to a Proprietary Subnet

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Vikas Singh, CSIS Dept. BITS Pilani



SNA, OSI, and Internet



Similarity between SNA and OSI



Simplicity of Internet; specifies only layers 3 and 4



Integrated application layers over Internet



Commonality of layers 1 and 2
-

IEEE standard

1
-
22

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Vikas Singh, CSIS Dept. BITS Pilani



Application Protocols


Internet user



OSI user

Telnet



Virtual Terminal


File Transfer

Protocol

File Transfer Access & Mgmt


Simple Mail Transfer

Message
-
oriented Text


Protocol



Interchange Standard


Simple Network


Common Management

Management Protocol Information Protocol

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Vikas Singh, CSIS Dept. BITS Pilani



NM Case Histories



The case of the Footprint (topology)



Case of the crashing bridge

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Vikas Singh, CSIS Dept. BITS Pilani



Common Network Problems



Loss of connectivity



Duplicate IP address


(address management)



Intermittent problems



Network configuration issues



Non
-
problems



Performance problems

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Vikas Singh, CSIS Dept. BITS Pilani

Challenges of IT Managers



Reliability



Non
-
real time problems



Rapid technological advance



Managing client/server environment



Scalability



Troubleshooting tools and systems



Trouble prediction



Standardization of operations
-

NMS helps



Centralized management vs “sneaker
-
net”

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Vikas Singh, CSIS Dept. BITS Pilani

Network Management

System Functionality


OAM&P



Operations



Administration



Maintenance



Provisioning


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Vikas Singh, CSIS Dept. BITS Pilani




Network Management




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Vikas Singh, CSIS Dept. BITS Pilani



NM Functional Flow Chart

1
-
28

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Vikas Singh, CSIS Dept. BITS Pilani

Network and system management


System management: Includes the management of entire system, including the
applications


If a user can not access a web page or can not send his/her e
-
mail, it does not matter
to him where the problem is. The problem may be with the user’s client, e
-
mail
server etc. Or the problem may be in TCP/IP protocol.


Network management: problems in lower layers of the TCP/IP, ISO/OSI
architecture. Generally problems with network resources such as
hub/switches/routers, or connectivity problems


Usually each NE vendor has its own network management system


The network management system monitors all the network components, not
only a given NE.


Some examples are HP Ovenview, IBM Netview, Spectrum, Ciscoworks.


The trend is to integrate System and network management systems.

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Vikas Singh, CSIS Dept. BITS Pilani

Network Management architecture

(functional)

The common management messages consist of
management information data (such as the type,
id, and status of managed objects..)


Vendor A

Vendor B

Common
management
messages

1. The common messages: management and information data

Exchange of monitoring data

2. Management controls


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Vikas Singh, CSIS Dept. BITS Pilani

Services and protocols

Vendor A

objects

objects

Vendor B

objects

objects

Application
Services

Management
Protocol

Transport
Protocols

Application services: management related applications,
such as configuration management, fault management

Management protocols are SNMP and CMIP


-

CMIP is complex and not used very much


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Vikas Singh, CSIS Dept. BITS Pilani



NM Components

NMS: Manages multiple network elements, via
Network agents. Each Network element could have
multiple objects.

Note the Hierarchy

Same Domain

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Vikas Singh, CSIS Dept. BITS Pilani



Interoperability



Message exchange between NMSs managing different domains

Two cooperating domains provide some services which are joint.

The Communication between the 2 NMSs, allows NMS of Domain
A/B, to integrate the Management information from the other
domain

Domain A

Domain B

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Vikas Singh, CSIS Dept. BITS Pilani

Network management protocols


CMIP (Common Management Information
Protocol) for OSI model


SNMP (Simple Network Management Protocol)
for TCP/IP (internet)



TMN (Telecommunication Management Network)
standard for managing telecommunication
networks. Issues for managing telecom network
are little different, than TCP/IP network, so ITU
has come up with TMN framework and
architecture

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Vikas Singh, CSIS Dept. BITS Pilani



Status and Future Trends



Status:



SNMP management



Limited CMIP management



Operations systems



Polled systems



Future trends:


Service and policy management



Business management



Web
-
based management

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Vikas Singh, CSIS Dept. BITS Pilani

Appendix

Internet History

Internet History



Internet is a result of research funded by Defense Advanced Reassert
Projects Agency (DARPA) in the late sixties


This research was directed towards connecting different types of
computers with different interfaces and over different physical links


This technology includes a set of network standards, a set of
procedures/conventions for interconnecting networks and routing
traffic among them


Initially, this technology was used for computer communications
between research oriented US Federal Government departments, and
research institutes


Now, this technology is commercially used everywhere in the world,
and thousands of ISPs around the world provide Internet service


Internet in technical terms is a collection of networks that are
interconnected by Routers/Gateways


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Vikas Singh, CSIS Dept. BITS Pilani

Internet History



1962: RAND Paul Baran, of the RAND Corporation (a government agency), was
commissioned by the U.S. Air Force to do a study on how it could maintain its
command and control over its missiles and bombers, after a nuclear attack. His final
proposal was a packet switched network.


1968: ARPA awarded the ARPANET contract to BBN. BBN had selected a
Honeywell minicomputer as the base on which they would build the switch


Backbones: 50Kbps ARPANET
-

Hosts: 4


1972: he first e
-
mail program was created by Ray Tomlinson of BBN.

The Advanced Research Projects Agency (ARPA) was renamed The Defense
Advanced Research Projects Agency (or DARPA)


Backbones: 50Kbps ARPANET
-

Hosts: 23


ARPANET was currently using the Network Control Protocol or NCP to
transfer data.This allowed communications between hosts running on the same
network.


1973: Development began on the protocol later to be called TCP/IP, it was
developed by a group headed by Vinton Cerf from Stanford and Bob Kahn from
DARPA. This new protocol was to allow diverse computer networks to
interconnect and communicate with each other.


Backbones: 50Kbps ARPANET
-

Hosts: 23+


1974: First Use of term Internet by Vint Cerf and Bob Kahn in paper on
Transmission Control Protocol.


Backbones: 50Kbps ARPANET
-

Hosts: 23+

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Vikas Singh, CSIS Dept. BITS Pilani

Internet History (Cont’d)


1983: Internet Activities Board (IAB) was created in 1983.


On January 1st, every machine connected to ARPANET had to use TCP/IP. TCP/IP
became the core Internet protocol and replaced NCP entirely.


The University of Wisconsin created Domain Name System (DNS)


Backbones: 50Kbps ARPANET, 56Kbps CSNET, plus satellite and radio
connections
-

Hosts: 562


1984: Arpanet divided into MILNET and ARPANET. Upgrade to CSNET was
contracted to MCI. New circuits would be T1. IBM would provide advanced
routers and Merit would manage the network. New network was to be called
NSFNET (National Science Foundation Network), and old lines were to remain
called CSNET.


Backbones: 50Kbps ARPANET, 56Kbps CSNET, plus satellite and radio
connections
-

Hosts: 1024


1985: The National Science Foundation began deploying its new T1 lines, which
would be finished by 1988.


Backbones: 50Kbps ARPANET, 56Kbps CSNET, 1.544Mbps (T1) NSFNET, plus
satellite and radio connections
-

Hosts: 1961


1986:The Internet Engineering Task Force or IETF was created to serve as a forum for
technical coordination by contractors for DARPA working on ARPANET, US Defense Data
Network (DDN), and the Internet core gateway system.


Backbones: 50Kbps ARPANET, 56Kbps CSNET, 1.544Mbps (T1) NSFNET, plus satellite and radio
connections
-

Hosts: 2308


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Vikas Singh, CSIS Dept. BITS Pilani

Internet History (Cont’d)


1987: BITNET and CSNET merged to form the Corporation for Research and
Educational Networking (CREN), another work of the National Science
Foundation.


Backbones: 50Kbps ARPANET, 56Kbps CSNET, 1.544Mbps (T1) NSFNET, plus
satellite and radio connections
-

Hosts: 28,174


1988: Plans to upgrade the network


Backbones: 50Kbps ARPANET, 56Kbps CSNET, 1.544Mbps (T1) NSFNET, plus
satellite and radio connections
-

Hosts: 56,000


1990: Merit, IBM and MCI formed a not for profit corporation called ANS,
Advanced Network & Services, which was to conduct research into high speed
networking.



It soon came up with the concept of the T3, a 45 Mbps line. NSF quickly
adopted the new network and by the end of 1991 all of its sites were connected
by this new backbone.


While the T3 lines were being constructed, the Department of Defense
disbanded the ARPANET and it was replaced by the NSFNET backbone. The
original 50Kbs lines of ARPANET were taken out of service.


Tim Berners
-
Lee and CERN in Geneva implements a hypertext system to
provide efficient information access to the members of the international high
-
energy physics community.


Backbones: 56Kbps CSNET, 1.544Mbps (T1) NSFNET, plus satellite and
radio connections
-

Hosts: 313,000


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Vikas Singh, CSIS Dept. BITS Pilani

Internet History (Cont’d)


1991: CSN discontinued: The operational costs of CREN are fully met through
dues paid by its member organizations.


The NSF established a new network, the National Research and Education Network
(NREN). The purpose of this network is to conduct high speed networking research. It
was not to be used as a commercial network, nor was it to be used to send a lot of the
data that the Internet now transfers.


Backbones: Partial 45Mbps (T3) NSFNET, a few private backbones, plus satellite and
radio connections
-

Hosts: 617,000


1992: Internet Society is chartered.


World
-
Wide Web released by CERN.


NSFNET backbone upgraded to T3 (44.736Mbps)


Backbones: 45Mbps (T3) NSFNET, private interconnected backbones consisting mainly
of 56Kbps, 1.544Mbps, plus satellite and radio connections
-

Hosts: 1,136,000


1993:InterNIC created by NSF to provide specific Internet services: directory and
database services (by AT&T), registration services (by Network Solutions Inc.),
and information services (by General Atomics/CERFnet).

Marc Andreessen and NCSA and the University of Illinois develops a graphical
user interface to the WWW, called "Mosaic for X".


Backbones: 45Mbps (T3) NSFNET, private interconnected backbones consisting mainly
of 56Kbps, 1.544Mbps, and 45Mpbs lines, plus satellite and radio connections
-

Hosts:
2,056,000

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Vikas Singh, CSIS Dept. BITS Pilani

Internet History (Cont’d)


1994: No major to the physical network. The most significant thing that happened
was the growth. Many new networks were added to the NSF backbone. Hundreds
of thousands of new hosts were added to the INTERNET during this time period.


Pizza Hut offers pizza ordering on its Web page.


First Virtual, the first cyber bank, opens.


ATM (Asynchronous Transmission Mode, 145Mbps) backbone is installed on
NSFNET.


Backbones: 145Mbps (ATM) NSFNET, private interconnected backbones
consisting mainly of 56Kbps, 1.544Mbps, and 45Mpbs lines, plus satellite and
radio connections
-

Hosts: 3,864,000


1995: The National Science Foundation announced that as of April 30, 1995 it
would no longer allow direct access to the NSF backbone. The National Science
Foundation contracted with four companies that would be providers of access to the
NSF backbone (Merit). These companies would then sell connections to groups,
organizations, and companies.


$50 annual fee is imposed on domains, excluding .edu and .gov domains which
are still funded by the National Science Foundation.


Backbones: 145Mbps (ATM) NSFNET (now private), private interconnected
backbones consisting mainly of 56Kbps, 1.544Mbps, 45Mpbs, 155Mpbs lines
in construction, plus satellite and radio connections
-

Hosts: 6,642,000

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Vikas Singh, CSIS Dept. BITS Pilani

Internet History (Cont’d)


1996: Most Internet traffic is carried by backbones of independent ISPs, including
MCI, AT&T, Sprint, UUNet, BBN planet, ANS, and more.


Currently the Internet Society, the group that controls the INTERNET, is trying to
figure out new TCP/IP to be able to have billions of addresses, rather than the
limited system of today. The problem that has arisen is that it is not known how
both the old and the new addressing systems will be able to work at the same time
during a transition period.


Backbones: 145Mbps (ATM) NSFNET (now private), private interconnected
backbones consisting mainly of 56Kbps, 1.544Mbps, 45Mpbs, and 155Mpbs lines,
plus satellite and radio connections
-

Hosts: over 15,000,000, and growing rapidly



1996 to 2005: explosive growth, e
-
commerce, e
-
gov, e
-
verything

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Vikas Singh, CSIS Dept. BITS Pilani



A Brief summary of Internet

1968/69

ARPANet

With 4 nodes

BB Speed

50 Kbps

1972

First e
-
mail program

Agency renamed DARPA

BB 50Kbps Hosts: 23

On the same network

Protocol:NCP

Hosts on the same network




1973/74

Development began on
TCP/IP. First use of the
Term Internet By V.
CERF

BB 50Kbps Hosts: 23+


1976

Dr. Metcalf Developed

Ethernet

Backbones: 50Kbps
ARPANET,

plus satellite and

radio connections

-

Hosts: 111+

TCP/IP Experiments


USENET

Based on UUCP

developed by ATT

BITnet by IBM: first

store and forward network

Application: e
-
mail and


list serve

BB: same as in 1976


1979

1981

NSF created CSNet for

Connecting Institutions

CSNET and ARPAnet

Connectivity proposed

By Cerf. Backbones:

50Kbps ARPANET,

56Kbps CSNET,

plus satellite/ radio

Hosts: 213


1983

IAB created

Ist Jan: TCP/IP

Hosts: 562




1984

ARPAnet divided
Milnet and

ARPAnet

CSNET managed
by MCI, and
called NSFNet

NSFnet backbone

Will use T
-
1

Hosts: 1024


1986

IETF created

To
coordinate

The
development
by various
contractors

Hosts: 2308


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Vikas Singh, CSIS Dept. BITS Pilani



A Brief summary of Internet


1986 to 1991: Internet Hosts and back bone speeds continued to grow


1992: Tim Berners
-
Lee and CERN in Geneva implements a hypertext system to provide efficient
information access to the members of the international high
-
energy physics community.


Backbones: 56Kbps CSNET, 1.544Mbps (T1) NSFNET, plus satellite and radio connections
-

Hosts: 313,000


1993:InterNIC created by NSF to provide specific Internet services: directory and database services
(by AT&T), registration services (by Network Solutions Inc.), and information services (by General
Atomics/CERFnet).

Marc Andreessen and NCSA and the University of Illinois develops a graphical user interface to the
WWW, called "Mosaic for X".


Backbones: 45Mbps (T3) NSFNET, private interconnected backbones consisting mainly of
56Kbps, 1.544Mbps, and 45Mpbs lines, plus satellite and radio connections
-

Hosts: 2,056,000


1994: Pizza Hut offers pizza ordering on its Web page Hosts: 3,864,000


1995: The National Science Foundation announced that as of April 30, 1995 it would no longer allow
direct access to the NSF backbone. The National Science Foundation contracted with four companies
that would be providers of access to the NSF backbone (Merit). These companies would then sell
connections to groups, organizations, and companies.


BB speed from 56 kbps to 155 Mbps


Hosts: 6,642,000


1996: Most Internet traffic is carried by backbones of independent ISPs, including MCI, AT&T,
Sprint, UUNet, BBN planet, ANS, and more


Hosts: over 15,000,000, and growing rapidly


1996 to 2006: explosive growth, e
-
commerce, e
-
gov, e
-
verything and all countries


Lack of address space


62

Vikas Singh, CSIS Dept. BITS Pilani