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Introduction to TCP/IP. What is TCP/IP. T ransmission C ontrol P rotocol/ I nternet P rotocol 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 Characteristics.
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What 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 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
FDDI TCP/IP Internetworking Router Token Ring Private Nets and Internet
LAN 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 Ethernet Switch ATM Switch Bridge Hub Router
X.25 or Frame Relay Switch Modem CSU/DSU TA/NT1 Comm. Server ATM Switch Router Multiplexor S stat mux Wide-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
Internet TCP/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 TCP/IP Comm. Software
TCP/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 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 97 16M
Internet 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 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 Tracks Circulated technical documents call Request For Comments RFC Internet Draft Revision RFC protocol specifications should be stable technically and should have no bugs or holes. Proposed Standard at least 2 independent and interoperable implementations that test all specification funcions Draft Standard have had significant field use and clear community interest in production use. Official Standard
Protocol Status Levels • All TCP/IP protocols have one of the following five status levels • Required • Recommended • Elective • Limited use • Not recommended
Internet 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 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 Layers Application Network Applications End-to-end Services Transport Internet Routing Network Network Interface Physical Transmission
Application Presentation Session Transport Network Data Link Physical TCP/IP and OSI OSI TCP/IP Application Transport Internet Network Physical
TCP/IP majors protocols Application FTP TELNET SMTP TFTP NFS NTP SNMP NNTP DNS BOOTP DHCP HTTP X-windows Transport TCP UDP Internet IP Network Network Driver Software Physical
Communications 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)
Client-Server Relationships FTP Protocol FTP Server FTP Client • 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 Protocol TELNET Server TELNET Server TELNET Protocol TELNET Client TELNET Client FTP Protocol FTP Cleint FTP Server
Applications 1 2 3 4 ( ) ( ) ( ) ( ) Transport Network access Port 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