Chapter Objectives

After completing this chapter you will be able to:

Describe the history of TCP/IPDescribe the history of the InternetOutline the different functions of the Internet organisations

(IAB, IETF, IRTF, IANA)Describe Request for Comments (RFCs)Outline the OSI 7-layer modelOutline the TCP/IP protocol stack

History of TCP/IP

1969: ARPANET went into operation

– four packet-switched nodes at three different sites

– connected together via 56 kbit/s circuits

– using the Network Control Protocol (NCP)

– funded by the U.S. Department of Defence

1974: TCP/IP designed by Vinton G. Cerf and Robert E. Kahn

1979: IP version 4 documented

History of TCP/IP (Contd)

1979: the Internet Control and Configuration Board (ICCB) formed

1979: BSD Unix with TCP/IP supplied to Universities

1980: ARPA started converting machines to TCP/IP

1983: mandate that all computers connected to ARPANET use

TCP/IP

1983 ARPANET split into two separate networks,

– ARPANET for further research

– MILNET for the military

History of the Internet1985: the ARPANET was heavily used and congested

1986: NSFNET developed to replace ARPANET

– universities and research organisations connected to regional networks

– regional networks connected to a main backbone

– six nationally funded super-computer centres connected to backbone

– The original links were 56 kbit/s.

1988: Links upgraded to T1 (1.544 Mbit/s)

– The NSFNET T1 backbone connected a total of 13 sites

1991: NSF decided to move the backbone to a private company

1993: New Internet backbone, ANSNET, with T3 (45 Mbit/s) links

1993: Final NSF solicitations

Today's Internet

Distributed architecture operated by commercial Network Service Providers (NSPs)

Connected together at Network Access Points (NAPs)

– high-speed switch to which a number of routers can be connected for the purpose of traffic exchange

– allows Internet traffic from the customers of one provider to reach the customers of another provider.

ISPs provide Internet services to end customers

Connection point between a customer and an ISP is called a point of presence (POP)

ISP networks exchange information with each other by connecting to NSPs that are connected to NAPs, or by connecting directly to NAPs

San Francisco

National Center forAtmospheric Research

San DiegoSupercomputer Center

Houston

Denver

Ameritech NAP

Chicago

National Center forSupercomputingApplications

Cleveland

Perryman, MD

Sprint NAP

MFS NAP

PittsburghSupercomputing

Center

Los Angeles

Atlanta

New York City

vBNS Backbone Network Map

Boston

Washington, DC

Seattle

R

R

R

R

RR

R

R

R

R

R

R

R

R

R

R

Router

ATM Switch

NAP

R DS-3

OC-3C

OC-12C

OC-48

R

R

R

Internet Architecture Board (IAB) Organisation

The IAB Board

IRSG IESG

Research groups Working groups

IRTF IETF

The IAB organisation

Active IETF Working Groups

Applications

Internet

Operations and Management

Routing

Security

Transport

User services

General

Internet Research Task Force

Active IRTF Research Groups– End-to-End

– Information Infrastructure Architecture

– Internet Resource Discovery

– Network Management

– Reliable Multicast

– Routing

– Secure Multicast

– Services Management

Internet Assigned Number Authority (IANA)

IANA

RIPE Reseaux IP Europeen

APNIC AsiaPacificNetworkInformation Centre

ARIN American Registry for Internet Numbers

RFC Standards Track Process

DraftPaper

RFCSpec

ProposedStandard

Standard

Review by IETF and IESG not to exceed two years

IESG recommends promotion to proposed standard. RFC publishes as RFC. Otherwise it is sent back to the IETF work group.

Implementation and test for a minimum of 6 months

DraftStandard

Evaluation of implementation for a minimum of 4 months

Important RFCs

1 2500 Internet Official Protocol Standards

STDNumber

RFCNumber

Name

Requirements for IP Version 4 Routers

Requirements for Internet hosts

Assigned Numbers

3

17002

18124*

11221123

www.rfc-editor.org/rfc.html

OSI 7- Layer Model

PHYSICAL

DATA LINK

NETWORK

TRANSPORT

SESSION

PRESENTATION

APPLICATIONInterfaces directly with application programs running on the devices.

Provides code conversion and data reformatting.

Co-ordinates interaction between end-to-end application processes.Provides end-to-end data integrity and quality of service.Switches and routes information to the appropriate network device.Transfers units of information to the other end of the physical link.

Transmits/Receives on the network medium

OSI 7- Layer Model and Internetworking Devices

Repeater

Bridge/Switch

Router

Data

Data

Data

Data

101100011110101010010

Data

DataT

A

N

S

P

D

Data

Data

Data

Data

101100011110101010010

Data

DataT

A

N

S

P

D

SYSTEM A SYSTEM B

Internet Protocol Suite and OSI Reference Model

DATA LINK

PHYSICAL

NETWORK

TRANSPORT

SESSION

APPLICATIONPRESENTATION

NETWORK INTERFACE(LAN - ETH, TR, FDDI)

(WAN - Serial lines, FR, ATM)

INTERNET PROTOCOL (IP)

TRANSPORT (TCP or UDP)

APPLICATION (FTP, TELNET, SNMP,

DNS, SMTP )

ICMP, IGMP

ARP, RARP

TCP/IP Protocol Stack Based on Data Flow

OSPF EGP TCP UDP ICMP IGMP

IP RARPARP

RIP BGP

Ethernet, Token Ring, PPP, and so on

Telnet, FTP, TFTP,HTTP,SNMP,SMTP, and so on

Port Number

Protocol Number

Type code

Application Layer

Data LinkLayer

InternetLayer

TransportLayer