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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
Introduction to TCP/IP
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
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What is TCP/IP
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Transmission Control Protocol/Internet Protocol
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TCP/IP refers to an entire suite of networking
protocols, developed for use on the Internet
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
TCP/IP Characteristics
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TCP/IP provides the services necessary to
interconnect computers and to interconnect networks,
creating the Internet
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Independence from underlying network topology,
physical network hardware, and OS
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Unique IP Address
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Universal connectivity throughout the network
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Standardize high-level protocols
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
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TCP/IP Internetworking
Token
Ring
FDDI
Private Nets
and Internet
Router
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
LAN and Devices
LANs are designed to :
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Operate within a limited geographic area
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Allow multiaccess to high-bandwidth media
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Control the network privately under local administration
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Provide full-time connectivity to local services
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Connect physically adjacent devices
ATM
Switch
Ethernet
Switch
Bridge
Hub
Router
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
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Wide-Area Networks and Devices
WANs are designed to :
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Operate over geography of telecommunications carriers
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Allow access over serial interfaces operating at lower speeds
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Control the network subject to regulated public services
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Provide full-time and part-time connectivity
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Connect devices separated over wide, even global areas
ATM
Switch
Router
Modem
CSU/DSU
TA/NT1
S
X.25 or
Frame Relay
Switch
Comm.
Server
Multiplexor
stat
mux
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
TCP/IP Networking Software
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TCP/IP protocol suites define a set of universal
communication services
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Services can be implemented in a standardized
manner in the networking software, normally bundled
with OS
TCP/IP
Comm.
Software
Internet
TCP/IP
Comm.
Software
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TCP/IP and Internet
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1957 USSR sputnik, USA established ARPA
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1969 ARPA funded ARPANET
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1971 Network with 15 nodes
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1974 Cerf/Kahn Protocol
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1973 Ethernet (Ph.D Disssertation Bob Metcalfe)
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1982/83 TCP/IP as a core protocol
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
Internet growth
Year #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
1/97 16M
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Internet Technical Bodies
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ISOC - Internet Society.
Professional society to
promote the use of Internet for research and scholar
communication and collaboration
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IAB - Internet Archtecture Board.
Technical
oversight and coordination, falls under ISOC
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IETF - Internet Engineering Task force.
Current
protocols and specifications for standardization.
Meets 3 times a year, organized in working groups
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IRTF - Internet Research Task force.
Research
oriented for future.
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
Internet Administrations
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DDN
-
the USA Defense Data Network is the government
organization that has overall responsibilty for administrating the
Internet
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DDN NIC (Network Information Center)
assigns unigues names and addresses
collects and distributes information about TCP/IP protocols
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IANA Internet Assigned Numbers Authority
assigns valur for network parameters, name of services,
identifiers
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NOC (Network Operations Center)
manages communication links
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
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IAB Standard Tracks
RFC
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 independence and interoparable
implementation that test all specification
funcions
have had significant field use and clear
communinity interest in production use.
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
Protocol Status Levels
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All TCP/IP protocol have one of the following five
status levels
Required
Recommended
Elective
Limited use
Not recommended
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Internet documents
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RFC
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number with RFC XXXX, more than 1700 nows
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updated RFCs are published with ne RFC numbers
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not all RFCs describe protocols. not all RFCs are used
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ftp://ds.internic.net
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STD (STandDard)
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official Internet standard
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FYI (For Your Information)
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
Sample Documents
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RFC
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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)
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1879 I B. Manning, "Class A Subnet Experiment Results and
Recommendations", 01/15/1996. (Pages=6) (Format=.txt)
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FYI
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0023 Guide to Network Resource Tool. EARN Staff. March 1994.
(Format:TXT=235112 bytes) (Also RFC1580)
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0028 Netiquette Guidelines. S. Hambridge. October 1995.
(Format: TXT=46185 bytes) (Also RFC1855)
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
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TCP/IP Architectural Layers
Application
Transport
Internet
Network
Physical
Network
Applications
End-to-end
Services
Routing
Transmission
Network Interface
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
Physical
TCP/IP and OSI
Application
Presentation
Session
Transport
Network
Data Link
Physical
Application
Transport
Internet
Network
TCP/IP
OSI
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TCP/IP majors protocols
Physical
Application
Transport
Internet
Network
FTP TELNET SMTP TFTP NFS NTP SNMP NNTP
DNS BOOTP DHCP HTTP X-windows
TCP UDP
IP
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
Communications Protocols
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A Communication protocol that provides a data
transfer service can be either connection-oriented
or connectionless
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Connection-oriented --A connection is generated
before the data is exchanged (e.g. TCP)
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Connectionless -- Try its best to delivery data, no
need to establish connection (e.g. UDP)
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
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FTP
Server
Client-Server Relationships
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One application component,
called Server, provides a
well-defined services for application
components running, called client
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Clients make a request for a
services by transmitiing data to
the server.
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Servers reply by sending data
back to the client
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How the server knowns type of
services ?
TELNET
Server
TELNET
Client
FTP
Cleint
FTP
Cleint
FTP
Client
TELNET
Server
TELNET
Client
FTP
Server
FTP
Server
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)73 3URWRFRO
)73 3URWRFRO
7(/1(7 3URWRFRO
7(/1(7 3URWRFRO
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Department of Computer Engineering, Kasetsart University 204325 Introduction to Computer Communications and Networks
Port Assignments
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Servers are known by ports number
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FTP 20, TELNET 23, SMTP 25, HTTP 80
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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
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Unix store general used port in /etc/services
Applications
Transport
Network access
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