4/11/40 page 1 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Introduction to TCP/IP

4/11/40 page 2 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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

4/11/40 page 3 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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

4/11/40 page 4 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL TCP/IP Internetworking Token Ring FDDI Private Nets and Internet Router

4/11/40 page 5 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 ATM Switch Ethernet Switch BridgeHubRouter

4/11/40 page 6 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 ATM Switch Router Modem CSU/DSU TA/NT1 S X.25 or Frame Relay Switch Comm. Server Multiplexor stat mux

4/11/40 page 7 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 Internet TCP/IP Comm. Software

4/11/40 page 8 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 Disssertation Bob Metcalfe) 1982/83 TCP/IP as a core protocol BSD Unix with TCP/IP from UCB

4/11/40 page 9 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Internet growth Year #Hosts M M M M M 1/97 16M

4/11/40 page 10 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Internet Technical Bodies ISOC - Internet Society. Professional society to promote the use of Internet for research and scholar communication and collaboration IAB - Internet Archtecture 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.

4/11/40 page 11 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 unigues names and addresses collects and distributes information about TCP/IP protocols IANA Internet Assigned Numbers Authority assigns valur for network parameters, name of services, identifiers NOC (Network Operations Center) manages communication links

4/11/40 page 12 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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.

4/11/40 page 13 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Protocol Status Levels All TCP/IP protocol have one of the following five status levels Required Recommended Elective Limited use Not recommended

4/11/40 page 14 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Internet documents RFC number with RFC XXXX, more than 1700 nows updated RFCs are published with ne 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) RFCs series that do not contain protocol specifications

4/11/40 page 15 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 (Format:TXT= bytes) (Also RFC1580) 0028 Netiquette Guidelines. S. Hambridge. October (Format: TXT=46185 bytes) (Also RFC1855)

4/11/40 page 16 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL TCP/IP Architectural Layers Application Transport Internet Network Physical Network Applications End-to-end Services Routing Transmission Network Interface

4/11/40 page 17 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Physical TCP/IP and OSI Application Presentation Session Transport Network Data Link Physical Application Transport Internet Network TCP/IP OSI

4/11/40 page 18 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 TCP UDP IP Network Driver Software

4/11/40 page 19 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 -- Try its best to delivery data, no need to establish connection (e.g. UDP)

4/11/40 page 20 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL FTP Server Client-Server Relationships One application component, called Server, provides a well- defined services for application components running, called client Clients make a request for a services by transmitiing 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 Cleint FTP Client TELNET Server TELNET Client FTP Server FTP Server FTP Protocol TELNET Protocol

4/11/40 page 21 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 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 Reserved ports for well-known services Other reserved ports user-defined server ports Unix store general used port in /etc/services Applications Transport Network access ( ) ( )