Introduction to TCP/IP

What is TCP/IPWhat is TCP/IP

Transmission Control Protocol/Internet Protocol

TCP/IP refers to an entire suite of networking protocols, developed for use on the Internet

TCP and IP are certainly two of the most important

TCP/IP CharacteristicsTCP/IP Characteristics

TCP/IP provides the services necessary to interconnect computers and to interconnect networks, creating the Internet

Independence from underlying network topology, physical network hardware, and OS

Unique IP Address Universal connectivity throughout the network Standardize high-level protocols

TCP/IP InternetworkingTCP/IP Internetworking

TokenRing

FDDI

Private Netsand Internet

Router

LAN and DevicesLAN and Devices

LANs are designed to :

Operate within a limited geographic area Allow multiaccess to high-bandwidth media Control the network privately under local administration Provide full-time connectivity to local services Connect physically adjacent devices

ATMSwitch

EthernetSwitchBridge Hub Router

Wide-Area Networks and DevicesWide-Area Networks and Devices

WANs are designed to :

Operate over geography of telecommunications carriers Allow access over serial interfaces operating at lower speeds Control the network subject to regulated public services Provide full-time and part-time connectivity Connect devices separated over wide, even global areas

ATMSwitchRouter

ModemCSU/DSUTA/NT1

S

X.25 orFrame Relay

Switch

Comm.Server Multiplexor

statmux

TCP/IP Networking SoftwareTCP/IP Networking Software

TCP/IP protocol suites define a set of universal communication services

Services can be implemented in a standardized manner in the networking software, normally bundled with OS

TCP/IP Comm. Software

InternetTCP/IP Comm. Software

TCP/IP and InternetTCP/IP and Internet

1957 USSR sputnik, USA established ARPA 1969 ARPA funded ARPANET 1971 Network with 15 nodes 1974 Cerf/Kahn Protocol 1973 Ethernet (Ph.D Dissertation Bob Metcalfe) 1982/83 TCP/IP as a core protocol 1983 4.2 BSD Unix with TCP/IP from UCB (univ. of

California @ Berkley)

Internet growthInternet growthYear #Hosts

69 4

84 1024

87 28174

90 313000

91 617000

92 1.1M

93 2.0M

94 3.8M

95 6.6M

96 12.8M

97 16M

Internet Technical BodiesInternet Technical Bodies

ISOC - Internet Society. Professional society to promote the use of Internet for research and scholar communication and collaboration

IAB - Internet Architecture Board. Technical

oversight and coordination, falls under ISOC IETF - Internet Engineering Task force. Current

protocols and specifications for standardization. Meets 3 times a year, organized in working groups

IRTF - Internet Research Task force. Research oriented for future.

Internet AdministrationsInternet Administrations DDN - the USA Defense Data Network is the government

organization that has overall responsibilty for administrating the Internet

DDN NIC (Network Information Center) assigns unique names and addresses collects and distributes information about TCP/IP protocols

IANA Internet Assigned Numbers Authority assigns value for network parameters, name of services,

identifiers

NOC (Network Operations Center) manages communication links

IAB Standard TracksIAB Standard TracksRFC

Internet Draft

Proposed Standard

Draft Standard

Official Standard

Circulated technical documents call Request For Comments

Revision RFC

protocol specifications should be stable technically and should have no bugs or holes.

at least 2 independent and interoperable implementations that test all specification funcions

have had significant field use and clear community interest in production use.

Protocol Status LevelsProtocol Status Levels

All TCP/IP protocols have one of the following five status levels Required Recommended Elective Limited use Not recommended

Internet documentsInternet documents

RFC number with RFC XXXX, more than 1700 now updated RFCs are published with new RFC numbers not all RFCs describe protocols. not all RFCs are used ftp://ds.internic.net

STD (STandDard) official Internet standard

FYI (For Your Information) RFC series that do not contain protocol specifications

Sample DocumentsSample Documents

RFC 2030 I D. Mills, "Simple Network Time Protocol (SNTP)

Version 4 for IPv4, IPv6 and OSI", 10/30/1996. (Pages=18) (Format=.txt) (Obsoletes RFC1769)

1879 I B. Manning, "Class A Subnet Experiment Results and Recommendations", 01/15/1996. (Pages=6) (Format=.txt)

FYI 0023 Guide to Network Resource Tool. EARN Staff. March 1994.

(Format:TXT=235112 bytes) (Also RFC1580) 0028 Netiquette Guidelines. S. Hambridge. October 1995.

(Format: TXT=46185 bytes) (Also RFC1855)

TCP/IP Architectural LayersTCP/IP Architectural Layers

ApplicationApplication

TransportTransport

InternetInternet

NetworkNetwork

PhysicalPhysical

NetworkApplications

End-to-endServices

Routing

Transmission

Network Interface

PhysicalPhysical

TCP/IP and OSITCP/IP and OSI

ApplicationApplication

PresentationPresentation

SessionSession

TransportTransport

NetworkNetwork

Data LinkData Link

PhysicalPhysical

ApplicationApplication

TransportTransport

InternetInternet

NetworkNetwork

TCP/IPOSI

TCP/IP majors protocolsTCP/IP majors protocols

PhysicalPhysical

ApplicationApplication

TransportTransport

InternetInternet

NetworkNetwork

FTP TELNET SMTP TFTP NFS NTP SNMP NNTPFTP TELNET SMTP TFTP NFS NTP SNMP NNTPDNS BOOTP DHCP HTTP X-windowsDNS BOOTP DHCP HTTP X-windows

TCP UDPTCP UDP

IPIP

Network Driver SoftwareNetwork Driver Software

Communications ProtocolsCommunications Protocols

A Communication protocol that provides a data transfer service can be either connection-oriented or connectionless

Connection-oriented --A connection is generated before the data is exchanged (e.g. TCP)

Connectionless -- Tries its best to delivery data, no need to establish connection (e.g. UDP)

FTP Server

Client-Server RelationshipsClient-Server Relationships One application component,

called Server, provides well- defined services for application components running, called client

Clients make a request for services by transmitting data to the server.

Servers reply by sending data back to the client

How the server knowns type of services ?

TELNET Server

TELNET Client

FTP Cleint

FTP Client

TELNET Server

TELNET Client

FTP Server

FTP Protocol

FTP Protocol

TELNET Protocol

TELNET Protocol

Port AssignmentsPort Assignments

Servers are known by ports number FTP 20, TELNET 23, SMTP 25, HTTP 80

Port numbers are generally allocated by 0 --not used 1-255 --Reserved ports for well-known services 256-1023 --Other reserved ports 1024-65535 --user-defined server ports

Unix stores general used ports in /etc/services directory

Applications

Transport

Network access

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