* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Other Sample - Where can my students do assignments that require
Survey
Document related concepts
Net neutrality law wikipedia , lookup
Airborne Networking wikipedia , lookup
SIP extensions for the IP Multimedia Subsystem wikipedia , lookup
Wake-on-LAN wikipedia , lookup
Computer network wikipedia , lookup
TCP congestion control wikipedia , lookup
Piggybacking (Internet access) wikipedia , lookup
List of wireless community networks by region wikipedia , lookup
Cracking of wireless networks wikipedia , lookup
Deep packet inspection wikipedia , lookup
Zero-configuration networking wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Transcript
Basic Network Services IMT 546 – Lab 4 December 4, 2004 Agueda Sánchez Shannon Layden Peyman Tajbakhsh Basic Network Services • What network services are • What network protocols are • Three widely used protocols TCP/IP HTTP • Demo SMTP • Example • One new protocol IPv6 What Network Services are Network services are the capabilities that enable computers to communicate with each other Protocols define how they do it (the rules) In the TCP/IP model, “services” and “protocols” are often used interchangeably Network Protocols Protocols allow information to travel over the network There are different types of protocols Each protocol has a set of “rules” and agreements Information can be exchanged between computers because they have "agreed" to use the same protocol Connecting with X protocol; ready to receive instruction or message? Yes, I'm ready to receive message (ack) Send message or instruction TCP/IP STACK TCP-aware Applications (browser, IRC, News Reader, and more) Network File System (NFS) Redirector Remote File Service (RAs) Internet Message Access Protocol (IMAP) Network File System (NFS) File Transfer Protocol (FTP) TELNET Virtual Terminal Protocol Server Message Block (SMB) Application Simple Mail Transfer Protocol (SMTP) Transport Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Internet Internet Protocol (IP) Host to network Packet Driver Protocols Product Specific Driver Derfler F.J. Jr. , Freed, L., How Networks Work, (2003) Link Access Protocol Balance (LAPB) An Introduction to TCP TCP stands for Transmission Control Protocol It controls the transmission of packets of data over the Internet It supports the network at the transport layer Computers must run TCP to communicate with world wide web servers TCP relies on the IP service to deliver data to the host An Introduction to IP IP stands of Internet Protocol A set of rules to send and receive messages at the Internet address level Computers must run IP to communicate across the internet IP forwards each packet based on a four byte destination address (the IP number) (e.g, 192.156.1.1) Demo IPCONFIG and Ping HTTP Hyper-text transfer protocol (HTTP) is the protocol for exchanging text, graphic images, sound, video, and other multimedia files on the Internet Request transfer of data HTTP …cont. HTTP started in 1990 by Berners-Lee 1993 employed by Marc Andreeson of Netscape Initial vision to create “a common information space in which we communicate by sharing information“ Estimated 80% of internet traffic is over http How HTTP works Client (browser usually) sends a request to a server Request comes with a URL and usually an operation Server performs operation on the URL Server sends response HTTP Demo GET /dumprequest.html HTTP/1.1 Host: djce.org.uk User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.1.4322) Accept: image/gif, image/xxbitmap, image/jpeg, image/pjpeg, application/xshockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */* Accept-Encoding: gzip, deflate Accept-Language: en-us Referer: http://www.google.com/search?sourceid=navclient&ie=UTF8&q=http+%22request+method%3A+Get%22++examples+get+http% 2F1%2E1 Connection: Keep-Alive SMTP SMTP: Simple Mail Transfer Protocol – A protocol used to send email on the Internet. SMTP is a set of rules regarding the interaction between a program sending email and a program receiving email Message Delivery Server Message Delivery Server Mailbox Store Mailbox Store SMTP …cont. Email is delivered by having the source machine establish a TCP connection to port 25 of the destination machine. For successful delivery, both “sender” and “receiver” should "speaks" SMTP. After establishing the TCP connection to port 25, the sending machine, operating as the client, waits for the receiving machine, operating as the server, to talk first. SMTP …cont. SMTP is used for sending e-mail. IMAP (Internet Message Access Protocol) and POP3 (Post Office Protocol 3) are used to access e-mail messages. POP3 or IMAP let the user save messages in a server mailbox and download them periodically from the server. SMTP Example Date: Sat 27 Jun 87 13:26:31 EDT From: [email protected] To: [email protected] Subject: meeting Let's get together Monday at 1pm. RED 220 RED.RUTGERS.EDU SMTP Service at 29 Jun 87 05:17:18 EDT TOPAZ HELO topaz.rutgers.edu RED 250 RED.RUTGERS.EDU - Hello TOPAZ.RUTGERS.EDU TOPAZ MAIL From: RED 250 MAIL accepted TOPAZ RCPT To: RED 250 Recipient accepted TOPAZ DATA RED 354 Start mail input; end with . TOPAZ Date: Sat 27 Jun 87 13:26:31 EDT TOPAZ From: [email protected] TOPAZ To: [email protected] TOPAZ Subject: meeting TOPAZ TOPAZ Let's get together Monday at 1pm. TOPAZ . RED 250 OK TOPAZ QUIT RED 221 RED.RUTGERS.EDU Service closing transmission channel What is IPv6? To understand IPv6 lets review IPv4 Current version of the Internet Protocol used by TCP/IP IPv4 has not substantially changed since RFC 791 was published in 1981 Robust, easily implemented and interoperable, and has stood the test of scaling to the size of today’s Internet Impending exhaustion of IPv4 address space due to exponential growth of Internet IPv6 There are 14 key differences between IPv4 and IPv6, some of the key differences are: IPv4 IPv6 Addresses are 4 bytes in length Addresses are 16 bytes in length Security Optional Security Required Header includes options Extension headers (extensibility) Address Resolution Protocol (ARP) Neighbor Solicitation Messages Configured manual or via DHCP Does not require manual or DHCP configuration Must support a 576-byte packet size (possibly fragmented). Must support a 1280-byte packet size (without fragmentation). IPv4 Header Review Version Internet Header Length Type of Service Total Length Identification Flags Fragment Offset Time to Live Protocol Header Checksum Source Address Destination Address Options ... IPv6 Header Version Traffic Class Flow Label Payload Length Next Header Hop Limit Source Address Destination Address TCP/IP Protocol Architecture w/IPv6 OSI Model Layers TCP/IP Protocol Architecture Layers TCP/IP Protocol Suite Application Layer Presentation Layer Application Layer Telnet FTP HTTP DNS RIPng SNMP Session Layer Transport Layer Transport Layer TCP UDP ND Network Layer Internet Layer IPv6 MLD ICMPv6 Data Link Layer Physical Layer Network Interface Layer Ethernet Token Ring Frame Relay ATM Resources TCP • http://www.atlantawebhost.com/glossary-sz.php IP • http://www.atlantawebhost.com/glossary-hl.php HTTP • Derfler F.J. Jr. , Freed, L., How Networks Work, (2003) • http://www.w3.org/Protocols/HTTP/HTTP2.html • http://www.cs.virginia.edu/~zaher/classes/CS457/lectures/web.pdf • http://www.jmarshall.com/easy/http/ SMTP • https://www.namesecure.com/en_US/index.jhtml?cat=glossary&subCat =rst#smtp • http://www.lsoft.com/resources/glossary.asp#S • http://searchwebservices.techtarget.com/sDefinition/0,,sid26_gci214219 ,00.html • http://www2.rad.com/networks/1998/smtp/smtp.htm • http://networking.ittoolbox.com/pub/LC030701a.pdf Microsoft’s IPv6 web site • http://www.microsoft.com/windowsserver2003/technologies/ipv6/default .mspx