Computer Networks. Lecture 7: Application layer: FTP and HTTP. Marcin Bieńkowski. Institute of Computer Science University of Wrocław

Size: px
Start display at page:

Download "Computer Networks. Lecture 7: Application layer: FTP and HTTP. Marcin Bieńkowski. Institute of Computer Science University of Wrocław"

Transcription

1 Computer Networks Lecture 7: Application layer: FTP and Marcin Bieńkowski Institute of Computer Science University of Wrocław Computer networks (II UWr) Lecture 7 1 / 23

2 Reminder: Internet reference model 5 4 DNS BSD sockets interface UDP FTP TCP 3 IP ICMP 2 1 Ethernet ARP / RARP Computer networks (II UWr) Lecture 7 2 / 23

3 Outlook 1 FTP 2 Proxy servers Computer networks (II UWr) Lecture 7 3 / 23

4 FTP FTP Computer networks (II UWr) Lecture 7 4 / 23

5 FTP FTP File Transfer Protocol Protocol for sending/receiving files to/from server. Server listens on port 21. After connection, client uses unix-like commands For data transmission an additional port is opened. presentation Computer networks (II UWr) Lecture 7 5 / 23

6 FTP Connection for data (e.g., downloading a file) Active mode FTP client chooses a port, informs server about it and starts listening on that port. FTP server connects to this port and sends the data to it. Problematic if the client is behind a firewall. Passive mode Client requests that the server should choose a port Server picks a port, informs the client about it and starts to listen. Client connects to this port and receives data from it. Computer networks (II UWr) Lecture 7 6 / 23

7 Computer networks (II UWr) Lecture 7 7 / 23

8 HyperText Transfer Protocol Protocol for sending files (as FTP) Very mature and complex protocol version 1.1 Uses different namespace than FTP Uses port 80. Computer networks (II UWr) Lecture 7 8 / 23

9 URL (Uniform Resource Locator) (1) URL: Identifies a given resource Consists of two colon-separated parts scheme: (http, ftp, mailto, file,...) resource-dependent part Examples: ftp://ftp.kernel.org/pub/index.html Computer networks (II UWr) Lecture 7 9 / 23

10 URL (2) URL for schemes http, ftp Part after colon: // domain name optionally :port / resource identifier within a server Example: mbi/dyd/sieciw_10s/ Note: / in the identifier for denoting hierarchical structure. Resource identifier is not necessarily a path to the file! Computer networks (II UWr) Lecture 7 10 / 23

11 URL (2) URL for schemes http, ftp Part after colon: // domain name optionally :port / resource identifier within a server Example: mbi/dyd/sieciw_10s/ Note: / in the identifier for denoting hierarchical structure. Resource identifier is not necessarily a path to the file! Computer networks (II UWr) Lecture 7 10 / 23

12 request and reply How it works: User enters URL in the web browser, it is split into parts (we assume that scheme = http). Web browser establishes a connection with a web server on port 80. It sends a request (GET method) example. Server analyses the request, fetches appropriate file from the disk. Server set an appropriate reply header and MIME type. Server sends the file example. Server closes the connection (or waits for another request) Web browser performs an action depending on the MIME type (displays / uses plugin / uses external application). Computer networks (II UWr) Lecture 7 11 / 23

13 Keep-alive connections TCP connection hand-shake = large overhead. Usually web browser want to download many documents at once (e.g., html web page + pictures). /1.1 standard: connection is kept alive by default. Connection is closed if the requests contains Connection: close presentation Computer networks (II UWr) Lecture 7 12 / 23

14 MIME type For every file sent, the server should set Content-type field appropriately. Examples: text/plain text file text/html HTML page image/jpeg JPEG picture video/mpeg MPEG video application/msword DOC document application/pdf PDF document application/octet-stream sequence of bytes without an interpretation. Computer networks (II UWr) Lecture 7 13 / 23

15 replies Important types of replies: 200 OK 301 Moved Permanently 302 Found 304 Not Modified 401 Unauthorized 403 Forbidden 404 Not Found 500 Internal Server Error Computer networks (II UWr) Lecture 7 14 / 23

16 HTML was designed for sending hypertext = text + links to other texts. This role is played by HTML. + HTML = WWW. HTML standardization is a W3C task. Computer networks (II UWr) Lecture 7 15 / 23

17 HTML versions Quick look into history HTML 1.0, 2.0, mainly academic usage, content is most important. HTML 3.0, 3.2, 4.0, the emphasis is shifted to presentation (mixed with content) HTML 4.01 also known as everything is allowed, many sloppily written webpages the webbrowser has to cope not only with the complicated standard but also with dozens deviations from it. XHTML 1.0, based on XML, rigid structure, separates content and structure (HTML) from the presentation (CSS styles) rigid format = easier processing automatic processing of data on the webpage one HTML, many CSS = different versions for different recipients (PDA, phones, visibility impaired,...) Computer networks (II UWr) Lecture 7 16 / 23

18 Dynamic WWW Client-side dynamics Javascript: simple object-oriented interpreted language, code embedded in the HTML. Java applets, Flash, Silverlight application execution by different web browser plugins. Server-side dynamics URI may point to the program, whose output is HTML (+ header) CGI (Common Gateway Interface): standard allowing for execution of an arbitrary external program. Mechanisms integrated with the webserver (PHP, JSP, ASP, mod_perl,...) Forms, parameter passing (GET and POST methods) Cookies = session handling, itself is stateless. Computer networks (II UWr) Lecture 7 17 / 23

19 Dynamic WWW Client-side dynamics Javascript: simple object-oriented interpreted language, code embedded in the HTML. Java applets, Flash, Silverlight application execution by different web browser plugins. Server-side dynamics URI may point to the program, whose output is HTML (+ header) CGI (Common Gateway Interface): standard allowing for execution of an arbitrary external program. Mechanisms integrated with the webserver (PHP, JSP, ASP, mod_perl,...) Forms, parameter passing (GET and POST methods) Cookies = session handling, itself is stateless. Computer networks (II UWr) Lecture 7 17 / 23

20 Abuses of protocol Part of WWW services allows for non-human automatized access Instead of creating a new protocol use as transport. REST (Representational State Transfer) creating a web service using existing methods (GET, PUT, POST, DELETE) REST is not a standard, rather a philosophy. Easy to automatize, but also human-readable. Example services: ebay, Amazon, Twitter, Flickr,... Computer networks (II UWr) Lecture 7 18 / 23

21 Proxy servers Proxy servers Computer networks (II UWr) Lecture 7 19 / 23

22 Proxy servers Instead of direct connection to webserver, the browser may connect with the proxy server. What for? Limiting the traffic to the remote web pages web content is stored in proxy cache. Controlling access to web resources. Note: proxy server usually means WWW proxy, but other services also have proxy servers (ARP, DNS, DHCP, whois programming task!) Computer networks (II UWr) Lecture 7 20 / 23

23 Proxy servers Instead of direct connection to webserver, the browser may connect with the proxy server. What for? Limiting the traffic to the remote web pages web content is stored in proxy cache. Controlling access to web resources. Note: proxy server usually means WWW proxy, but other services also have proxy servers (ARP, DNS, DHCP, whois programming task!) Computer networks (II UWr) Lecture 7 20 / 23

24 Proxy server Proxy servers How it works: It listens usually on port If its cache does not contain the requested page or if it is outdated, then proxy connects to a given page, stores the reply in the cache. Proxy returns the answer to the client. Computer networks (II UWr) Lecture 7 21 / 23

25 Proxy server Proxy servers How it works: It listens usually on port If its cache does not contain the requested page or if it is outdated, then proxy connects to a given page, stores the reply in the cache. Proxy returns the answer to the client. Computer networks (II UWr) Lecture 7 21 / 23

26 Proxy server, cont. Proxy servers How the proxy checks whether the page in cache is up to date: WWW server sets a field Expires: in the reply header after this date, proxy evicts the page from the cache. WWW server may set the field Pragma: no-cache and/or Cache-Control: no-cache this page will not be stored in proxy cache at all. Client may set these fields in the request proxy will neglect the contents of its cache. In the remaining cases: heuristic based on the Last-modified: field. Computer networks (II UWr) Lecture 7 22 / 23

27 Anonymous proxy servers Proxy servers Normal proxy server adds its own fields to our request, e.g., X-Forwarded-For: (our IP address) Via: (proxy IP address) There are anonymous proxy server which do not add these headers presentation. Computer networks (II UWr) Lecture 7 23 / 23

Web. Services. Web Technologies. Today. Web. Technologies. Internet WWW. Protocols TCP/IP HTTP. Apache. Next Time. Lecture #3 2008 3 Apache.

Web. Services. Web Technologies. Today. Web. Technologies. Internet WWW. Protocols TCP/IP HTTP. Apache. Next Time. Lecture #3 2008 3 Apache. JSP, and JSP, and JSP, and 1 2 Lecture #3 2008 3 JSP, and JSP, and Markup & presentation (HTML, XHTML, CSS etc) Data storage & access (JDBC, XML etc) Network & application protocols (, etc) Programming

More information

Protocolo HTTP. Web and HTTP. HTTP overview. HTTP overview

Protocolo HTTP. Web and HTTP. HTTP overview. HTTP overview Web and HTTP Protocolo HTTP Web page consists of objects Object can be HTML file, JPEG image, Java applet, audio file, Web page consists of base HTML-file which includes several referenced objects Each

More information

Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ MEng. Nguyễn CaoĐạt

Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ MEng. Nguyễn CaoĐạt Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ MEng. Nguyễn CaoĐạt 1 Lecture 10: Application Layer 2 Application Layer Where our applications are running Using services provided by

More information

1. When will an IP process drop a datagram? 2. When will an IP process fragment a datagram? 3. When will a TCP process drop a segment?

1. When will an IP process drop a datagram? 2. When will an IP process fragment a datagram? 3. When will a TCP process drop a segment? Questions 1. When will an IP process drop a datagram? 2. When will an IP process fragment a datagram? 3. When will a TCP process drop a segment? 4. When will a TCP process resend a segment? CP476 Internet

More information

Network Technologies

Network Technologies Network Technologies Glenn Strong Department of Computer Science School of Computer Science and Statistics Trinity College, Dublin January 28, 2014 What Happens When Browser Contacts Server I Top view:

More information

HTTP. Internet Engineering. Fall 2015. Bahador Bakhshi CE & IT Department, Amirkabir University of Technology

HTTP. Internet Engineering. Fall 2015. Bahador Bakhshi CE & IT Department, Amirkabir University of Technology HTTP Internet Engineering Fall 2015 Bahador Bakhshi CE & IT Department, Amirkabir University of Technology Questions Q1) How do web server and client browser talk to each other? Q1.1) What is the common

More information

1 Introduction: Network Applications

1 Introduction: Network Applications 1 Introduction: Network Applications Some Network Apps E-mail Web Instant messaging Remote login P2P file sharing Multi-user network games Streaming stored video clips Internet telephone Real-time video

More information

Basic Internet programming Formalities. Hands-on tools for internet programming

Basic Internet programming Formalities. Hands-on tools for internet programming Welcome Basic Internet programming Formalities Hands-on tools for internet programming DD1335 (gruint10) Serafim Dahl serafim@nada.kth.se DD1335 (Lecture 1) Basic Internet Programming Spring 2010 1 / 23

More information

Internet Technologies. World Wide Web (WWW) Proxy Server Network Address Translator (NAT)

Internet Technologies. World Wide Web (WWW) Proxy Server Network Address Translator (NAT) Internet Technologies World Wide Web (WWW) Proxy Server Network Address Translator (NAT) What is WWW? System of interlinked Hypertext documents Text, Images, Videos, and other multimedia documents navigate

More information

Web Development. Owen Sacco. ICS2205/ICS2230 Web Intelligence

Web Development. Owen Sacco. ICS2205/ICS2230 Web Intelligence Web Development Owen Sacco ICS2205/ICS2230 Web Intelligence Brief Course Overview An introduction to Web development Server-side Scripting Web Servers PHP Client-side Scripting HTML & CSS JavaScript &

More information

World Wide Web. Before WWW

World Wide Web. Before WWW World Wide Web Joao.Neves@fe.up.pt Before WWW Major search tools: Gopher and Archie Archie Search FTP archives indexes Filename based queries Gopher Friendly interface Menu driven queries João Neves 2

More information

INTERNET ENABLED SYSTEMS NETWORK PROTOCOLS

INTERNET ENABLED SYSTEMS NETWORK PROTOCOLS DEVICES AND COMMUNICATION BUSES FOR DEVICES NETWORK Lesson-24: INTERNET ENABLED SYSTEMS NETWORK PROTOCOLS 1 Internet enabled embedded system Communication to other on the Internet. Use html (hyper text

More information

Internet Technologies_1. Doc. Ing. František Huňka, CSc.

Internet Technologies_1. Doc. Ing. František Huňka, CSc. 1 Internet Technologies_1 Doc. Ing. František Huňka, CSc. Outline of the Course 2 Internet and www history. Markup languages. Software tools. HTTP protocol. Basic architecture of the web systems. XHTML

More information

URLs and HTTP. ICW Lecture 10 Tom Chothia

URLs and HTTP. ICW Lecture 10 Tom Chothia URLs and HTTP ICW Lecture 10 Tom Chothia This Lecture The two basic building blocks of the web: URLs: Uniform Resource Locators HTTP: HyperText Transfer Protocol Uniform Resource Locators Many Internet

More information

WWW. World Wide Web Aka The Internet. dr. C. P. J. Koymans. Informatics Institute Universiteit van Amsterdam. November 30, 2007

WWW. World Wide Web Aka The Internet. dr. C. P. J. Koymans. Informatics Institute Universiteit van Amsterdam. November 30, 2007 WWW World Wide Web Aka The Internet dr. C. P. J. Koymans Informatics Institute Universiteit van Amsterdam November 30, 2007 dr. C. P. J. Koymans (UvA) WWW November 30, 2007 1 / 36 WWW history (1) 1968

More information

Chapter 27 Hypertext Transfer Protocol

Chapter 27 Hypertext Transfer Protocol Chapter 27 Hypertext Transfer Protocol Columbus, OH 43210 Jain@CIS.Ohio-State.Edu http://www.cis.ohio-state.edu/~jain/ 27-1 Overview Hypertext language and protocol HTTP messages Browser architecture CGI

More information

HTTP Protocol. Bartosz Walter

HTTP Protocol. Bartosz Walter <Bartek.Walter@man.poznan.pl> HTTP Protocol Bartosz Walter Agenda Basics Methods Headers Response Codes Cookies Authentication Advanced Features of HTTP 1.1 Internationalization HTTP Basics defined in

More information

Detailed Table of Contents

Detailed Table of Contents Detailed Table of Contents Foreword Preface 1. Networking Protocols and OSI Model 1 1.1 Protocols in Computer Communications 3 1.2 The OSI Model 7 1.3 OSI Layer Functions 11 Summary 19 Key Terms and Concepts

More information

The Web: some jargon. User agent for Web is called a browser: Web page: Most Web pages consist of: Server for Web is called Web server:

The Web: some jargon. User agent for Web is called a browser: Web page: Most Web pages consist of: Server for Web is called Web server: The Web: some jargon Web page: consists of objects addressed by a URL Most Web pages consist of: base HTML page, and several referenced objects. URL has two components: host name and path name: User agent

More information

Working With Virtual Hosts on Pramati Server

Working With Virtual Hosts on Pramati Server Working With Virtual Hosts on Pramati Server 13 Overview Virtual hosting allows a single machine to be addressed by different names. There are two ways for configuring Virtual Hosts. They are: Domain Name

More information

Network: several computers who can communicate. bus. Main example: Ethernet (1980 today: coaxial cable, twisted pair, 10Mb 1000Gb).

Network: several computers who can communicate. bus. Main example: Ethernet (1980 today: coaxial cable, twisted pair, 10Mb 1000Gb). 1 / 17 Network: several computers who can communicate. Bus topology: bus Main example: Ethernet (1980 today: coaxial cable, twisted pair, 10Mb 1000Gb). Hardware has globally unique MAC addresses (IDs).

More information

reference: HTTP: The Definitive Guide by David Gourley and Brian Totty (O Reilly, 2002)

reference: HTTP: The Definitive Guide by David Gourley and Brian Totty (O Reilly, 2002) 1 cse879-03 2010-03-29 17:23 Kyung-Goo Doh Chapter 3. Web Application Technologies reference: HTTP: The Definitive Guide by David Gourley and Brian Totty (O Reilly, 2002) 1. The HTTP Protocol. HTTP = HyperText

More information

Network Configuration Settings

Network Configuration Settings Network Configuration Settings Many small businesses already have an existing firewall device for their local network when they purchase Microsoft Windows Small Business Server 2003. Often, these devices

More information

Introduction to LAN/WAN. Application Layer (Part II)

Introduction to LAN/WAN. Application Layer (Part II) Introduction to LAN/WAN Application Layer (Part II) Application Layer Topics Domain Name System (DNS) (7.1) Electronic Mail (Email) (7.2) World Wide Web (WWW) (7.3) Electronic Mail (Email) Mostly used

More information

http://alice.teaparty.wonderland.com:23054/dormouse/bio.htm

http://alice.teaparty.wonderland.com:23054/dormouse/bio.htm Client/Server paradigm As we know, the World Wide Web is accessed thru the use of a Web Browser, more technically known as a Web Client. 1 A Web Client makes requests of a Web Server 2, which is software

More information

Connecting with Computer Science, 2e. Chapter 5 The Internet

Connecting with Computer Science, 2e. Chapter 5 The Internet Connecting with Computer Science, 2e Chapter 5 The Internet Objectives In this chapter you will: Learn what the Internet really is Become familiar with the architecture of the Internet Become familiar

More information

Domain Name System (DNS)

Domain Name System (DNS) Application Layer Domain Name System Domain Name System (DNS) Problem Want to go to www.google.com, but don t know the IP address Solution DNS queries Name Servers to get correct IP address Essentially

More information

BASIC ANALYSIS OF TCP/IP NETWORKS

BASIC ANALYSIS OF TCP/IP NETWORKS BASIC ANALYSIS OF TCP/IP NETWORKS INTRODUCTION Communication analysis provides powerful tool for maintenance, performance monitoring, attack detection, and problems fixing in computer networks. Today networks

More information

Lecture 2. Internet: who talks with whom?

Lecture 2. Internet: who talks with whom? Lecture 2. Internet: who talks with whom? An application layer view, with particular attention to the World Wide Web Basic scenario Internet Client (local PC) Server (remote host) Client wants to retrieve

More information

Web Application Security

Web Application Security Web Application Security The OWASP Foundation Securing the application Input validation Authorization Session mgmt Config mgmt Authenticatio n Error handling Web server App server DB server Secure storage

More information

CS640: Introduction to Computer Networks. Applications FTP: The File Transfer Protocol

CS640: Introduction to Computer Networks. Applications FTP: The File Transfer Protocol CS640: Introduction to Computer Networks Aditya Akella Lecture 4 - Application Protocols, Performance Applications FTP: The File Transfer Protocol user at host FTP FTP user client interface local file

More information

Introduction to Computer Security

Introduction to Computer Security Introduction to Computer Security Web Application Security Pavel Laskov Wilhelm Schickard Institute for Computer Science Modern threat landscape The majority of modern vulnerabilities are found in web

More information

Modern snoop lab lite version

Modern snoop lab lite version Modern snoop lab lite version Lab assignment in Computer Networking OpenIPLab Department of Information Technology, Uppsala University Overview This is a lab constructed as part of the OpenIPLab project.

More information

Fachgebiet Technische Informatik, Joachim Zumbrägel

Fachgebiet Technische Informatik, Joachim Zumbrägel Computer Network Lab 2015 Fachgebiet Technische Informatik, Joachim Zumbrägel Overview Internet Internet Protocols Fundamentals about HTTP Communication HTTP-Server, mode of operation Static/Dynamic Webpages

More information

Computer Networks. Lecture 3: IP Protocol. Marcin Bieńkowski. Institute of Computer Science University of Wrocław

Computer Networks. Lecture 3: IP Protocol. Marcin Bieńkowski. Institute of Computer Science University of Wrocław Computer Networks Lecture 3: IP Protocol Marcin Bieńkowski Institute of Computer Science University of Wrocław Computer networks (II UWr) Lecture 3 1 / 24 In previous lectures We learned about layer 1

More information

Web Programming. Robert M. Dondero, Ph.D. Princeton University

Web Programming. Robert M. Dondero, Ph.D. Princeton University Web Programming Robert M. Dondero, Ph.D. Princeton University 1 Objectives You will learn: The fundamentals of web programming... The hypertext markup language (HTML) Uniform resource locators (URLs) The

More information

Web Tracking for You. Gregory Fleischer

Web Tracking for You. Gregory Fleischer Web Tracking for You Gregory Fleischer 1 INTRODUCTION 2 Me Gregory Fleischer Senior Security Consultant at FishNet Security 3 Disclaimer Why do you hate? 4 Reasons For Tracking TradiFonal reasons for tracking

More information

CONTENT of this CHAPTER

CONTENT of this CHAPTER CONTENT of this CHAPTER v DNS v HTTP and WWW v EMAIL v SNMP 3.2.1 WWW and HTTP: Basic Concepts With a browser you can request for remote resource (e.g. an HTML file) Web server replies to queries (e.g.

More information

The Web History (I) The Web History (II)

The Web History (I) The Web History (II) Goals of Today s Lecture EE 122: The World Wide Web Ion Stoica TAs: Junda Liu, DK Moon, David Zats http://inst.eecs.berkeley.edu/~ee122/ (Materials with thanks to Vern Paxson, Jennifer Rexford, and colleagues

More information

By Bardia, Patit, and Rozheh

By Bardia, Patit, and Rozheh HTTP By Bardia, Patit, and Rozheh HTTP - Introduction - Hyper Text Transfer Protocol -uses the TCP/IP technology -has had the most impact on the World Wide Web (WWW) - specs in RFC 2616 (RFC2616) HTTP

More information

Evolution of the WWW. Communication in the WWW. WWW, HTML, URL and HTTP. HTTP Abstract Message Format. The Client/Server model is used:

Evolution of the WWW. Communication in the WWW. WWW, HTML, URL and HTTP. HTTP Abstract Message Format. The Client/Server model is used: Evolution of the WWW Communication in the WWW World Wide Web (WWW) Access to linked documents, which are distributed over several computers in the History of the WWW Origin 1989 in the nuclear research

More information

Proxies. Chapter 4. Network & Security Gildas Avoine

Proxies. Chapter 4. Network & Security Gildas Avoine Proxies Chapter 4 Network & Security Gildas Avoine SUMMARY OF CHAPTER 4 Generalities Forward Proxies Reverse Proxies Open Proxies Conclusion GENERALITIES Generalities Forward Proxies Reverse Proxies Open

More information

M3-R3: INTERNET AND WEB DESIGN

M3-R3: INTERNET AND WEB DESIGN M3-R3: INTERNET AND WEB DESIGN NOTE: 1. There are TWO PARTS in this Module/Paper. PART ONE contains FOUR questions and PART TWO contains FIVE questions. 2. PART ONE is to be answered in the TEAR-OFF ANSWER

More information

APACHE WEB SERVER. Andri Mirzal, PhD N28-439-03

APACHE WEB SERVER. Andri Mirzal, PhD N28-439-03 APACHE WEB SERVER Andri Mirzal, PhD N28-439-03 Introduction The Apache is an open source web server software program notable for playing a key role in the initial growth of the World Wide Web Typically

More information

Data Communication I

Data Communication I Data Communication I Urban Bilstrup (E327) 090901 Urban.Bilstrup@ide.hh.se www2.hh.se/staff/urban Internet - Sweden, Northern Europe SUNET NORDUnet 2 Internet - Internet Addresses Everyone should be able

More information

Description of Microsoft Internet Information Services (IIS) 5.0 and

Description of Microsoft Internet Information Services (IIS) 5.0 and Page 1 of 10 Article ID: 318380 - Last Review: July 7, 2008 - Revision: 8.1 Description of Microsoft Internet Information Services (IIS) 5.0 and 6.0 status codes This article was previously published under

More information

7 Why Use Perl for CGI?

7 Why Use Perl for CGI? 7 Why Use Perl for CGI? Perl is the de facto standard for CGI programming for a number of reasons, but perhaps the most important are: Socket Support: Perl makes it easy to create programs that interface

More information

Web Application Development

Web Application Development Web Application Development Introduction Because of wide spread use of internet, web based applications are becoming vital part of IT infrastructure of large organizations. For example web based employee

More information

CTIS 256 Web Technologies II. Week # 1 Serkan GENÇ

CTIS 256 Web Technologies II. Week # 1 Serkan GENÇ CTIS 256 Web Technologies II Week # 1 Serkan GENÇ Introduction Aim: to be able to develop web-based applications using PHP (programming language) and mysql(dbms). Internet is a huge network structure connecting

More information

Application Level Protocols

Application Level Protocols Application Level Protocols Nixu Oy PL 21 (Mäkelänkatu 91) 00601 Helsinki, Finland tel. +358 9 478 1011 fax. +358 9 478 1030 info@nixu.fi http://www.nixu.fi Contents Client-Server Store and Forward Push

More information

HTTP 1.1 Web Server and Client

HTTP 1.1 Web Server and Client HTTP 1.1 Web Server and Client Finding Feature Information HTTP 1.1 Web Server and Client Last Updated: August 17, 2011 The HTTP 1.1 Web Server and Client feature provides a consistent interface for users

More information

By : Khalid Alfalqi Department of Computer Science, Umm Al-Qura University

By : Khalid Alfalqi Department of Computer Science, Umm Al-Qura University By : Khalid Alfalqi Department of Computer Science, Umm Al-Qura University History of Web History of the Internet Basic Web System Architecture URL DNS Creating Static and Dynamic Information Security

More information

Transport and Network Layer

Transport and Network Layer Transport and Network Layer 1 Introduction Responsible for moving messages from end-to-end in a network Closely tied together TCP/IP: most commonly used protocol o Used in Internet o Compatible with a

More information

cnds@napier Slide 1 Introduction cnds@napier 1 Lecture 6 (Network Layer)

cnds@napier Slide 1 Introduction cnds@napier 1 Lecture 6 (Network Layer) Slide 1 Introduction In today s and next week s lecture we will cover two of the most important areas in networking and the Internet: IP and TCP. These cover the network and transport layer of the OSI

More information

THE PROXY SERVER 1 1 PURPOSE 3 2 USAGE EXAMPLES 4 3 STARTING THE PROXY SERVER 5 4 READING THE LOG 6

THE PROXY SERVER 1 1 PURPOSE 3 2 USAGE EXAMPLES 4 3 STARTING THE PROXY SERVER 5 4 READING THE LOG 6 The Proxy Server THE PROXY SERVER 1 1 PURPOSE 3 2 USAGE EXAMPLES 4 3 STARTING THE PROXY SERVER 5 4 READING THE LOG 6 2 1 Purpose The proxy server acts as an intermediate server that relays requests between

More information

Chapter 6 Virtual Private Networking Using SSL Connections

Chapter 6 Virtual Private Networking Using SSL Connections Chapter 6 Virtual Private Networking Using SSL Connections The FVS336G ProSafe Dual WAN Gigabit Firewall with SSL & IPsec VPN provides a hardwarebased SSL VPN solution designed specifically to provide

More information

Introduction to Computer Security Benoit Donnet Academic Year 2015-2016

Introduction to Computer Security Benoit Donnet Academic Year 2015-2016 Introduction to Computer Security Benoit Donnet Academic Year 2015-2016 1 Agenda Networking Chapter 1: Firewalls Chapter 2: Proxy Chapter 3: Intrusion Detection System Chapter 4: Network Attacks Chapter

More information

Cape Girardeau Career Center CISCO Networking Academy Bill Link, Instructor. 2.,,,, and are key services that ISPs can provide to all customers.

Cape Girardeau Career Center CISCO Networking Academy Bill Link, Instructor. 2.,,,, and are key services that ISPs can provide to all customers. Name: 1. What is an Enterprise network and how does it differ from a WAN? 2.,,,, and are key services that ISPs can provide to all customers. 3. Describe in detail what a managed service that an ISP might

More information

CDN Operation Manual

CDN Operation Manual NTT Communications Cloudⁿ CDN Operation Manual Ver.1.1 Please refrain from secondary use such as distributing, reproducing, and transferring this document. 1 Version Number Edited on Revisions Ver.1.0

More information

IP addresses. IP addresses: IPv4: 32 bits: 10.110.4.199

IP addresses. IP addresses: IPv4: 32 bits: 10.110.4.199 Internet domain region of Internet operated by 1 entity (university, company, etc.) domain name assigned by registrars Top-level domains.edu,.com,.dk Example: login.imada.sdu.dk imada is a subdomain IP

More information

Application layer Web 2.0

Application layer Web 2.0 Information Network I Application layer Web 2.0 Youki Kadobayashi NAIST They re revolving around the web, after all Name any Internet-related buzz: Cloud computing Smartphone Social media... You ll end

More information

Networking Fundamentals: IP, DNS, URL, MIME

Networking Fundamentals: IP, DNS, URL, MIME Networking Fundamentals: IP, DNS, URL, MIME Computer Science and Engineering College of Engineering The Ohio State University Lecture 10 Internet Protocol (IP) Addresses A unique 32-bit number Assigned

More information

Lab Exercise HTTP. Objective. Step 1: Capture a Trace

Lab Exercise HTTP. Objective. Step 1: Capture a Trace Lab Exercise HTTP Objective HTTP (HyperText Transfer Protocol) is the main protocol underlying the Web. The trace file is here: http://scisweb.ulster.ac.uk/~kevin/com320/labs/wireshark/trace-http.pcap

More information

Outline Definition of Webserver HTTP Static is no fun Software SSL. Webserver. in a nutshell. Sebastian Hollizeck. June, the 4 th 2013

Outline Definition of Webserver HTTP Static is no fun Software SSL. Webserver. in a nutshell. Sebastian Hollizeck. June, the 4 th 2013 Definition of in a nutshell June, the 4 th 2013 Definition of Definition of Just another definition So what is it now? Example CGI php comparison log-file Definition of a formal definition Aisaprogramthat,usingthe

More information

Web Browsing Examples. How Web Browsing and HTTP Works

Web Browsing Examples. How Web Browsing and HTTP Works How Web Browsing and HTTP Works 1 1 2 Lets consider an example that shows how web browsing and HTTP work. The example will cover a simple, but very common case. There are many more details of HTTP that

More information

(World Wide) Web WWW. Web History

(World Wide) Web WWW. Web History (World Wide) Web WWW A way to connect computers that provide information (servers) with computers that ask for it (clients like you and me) uses the Internet, but it's not the same as the Internet URL

More information

LabVIEW Internet Toolkit User Guide

LabVIEW Internet Toolkit User Guide LabVIEW Internet Toolkit User Guide Version 6.0 Contents The LabVIEW Internet Toolkit provides you with the ability to incorporate Internet capabilities into VIs. You can use LabVIEW to work with XML documents,

More information

Computer Networks. Web and HTTP HTTP

Computer Networks. Web and HTTP HTTP Computer Networks HTTP 1 Web and HTTP First some jargon Web page consists of objects Object can be HTML file, JPEG image, Java applet, audio file, Web page consists of base HTML- file which includes several

More information

Application Layer -1- Network Tools

Application Layer -1- Network Tools EITF25 Internet: Technology and Applications Application Layer -1- Network Tools 2015, Lecture 08 Kaan Bür Previously on EITF25 Addressing above IP Ports, sockets Process-to-process delivery Transport

More information

SiteCelerate white paper

SiteCelerate white paper SiteCelerate white paper Arahe Solutions SITECELERATE OVERVIEW As enterprises increases their investment in Web applications, Portal and websites and as usage of these applications increase, performance

More information

Distributed Systems Principles and Paradigms

Distributed Systems Principles and Paradigms Distributed Systems Principles and Paradigms Chapter 12 (version October 15, 2007) Maarten van Steen Vrije Universiteit Amsterdam, Faculty of Science Dept. Mathematics and Computer Science Room R4.20.

More information

Internet Technologies 4-http. F. Ricci 2010/2011

Internet Technologies 4-http. F. Ricci 2010/2011 Internet Technologies 4-http F. Ricci 2010/2011 Content Hypertext Transfer Protocol Structure of a message Methods Headers Parameters and character encoding Proxy Caching HTTP 1.1: chunked transfer and

More information

10CS73:Web Programming

10CS73:Web Programming 10CS73:Web Programming Question Bank Fundamentals of Web: 1.What is WWW? 2. What are domain names? Explain domain name conversion with diagram 3.What are the difference between web browser and web server

More information

Using IPM to Measure Network Performance

Using IPM to Measure Network Performance CHAPTER 3 Using IPM to Measure Network Performance This chapter provides details on using IPM to measure latency, jitter, availability, packet loss, and errors. It includes the following sections: Measuring

More information

Step into the Future: HTML5 and its Impact on SSL VPNs

Step into the Future: HTML5 and its Impact on SSL VPNs Step into the Future: HTML5 and its Impact on SSL VPNs Aidan Gogarty HOB, Inc. Session ID: SPO - 302 Session Classification: General Interest What this is all about. All about HTML5 3 useful components

More information

Overview. Securing TCP/IP. Introduction to TCP/IP (cont d) Introduction to TCP/IP

Overview. Securing TCP/IP. Introduction to TCP/IP (cont d) Introduction to TCP/IP Overview Securing TCP/IP Chapter 6 TCP/IP Open Systems Interconnection Model Anatomy of a Packet Internet Protocol Security (IPSec) Web Security (HTTP over TLS, Secure-HTTP) Lecturer: Pei-yih Ting 1 2

More information

sessionx Desarrollo de Aplicaciones en Red Web Applications History (1) Content History (2) History (3)

sessionx Desarrollo de Aplicaciones en Red Web Applications History (1) Content History (2) History (3) sessionx Desarrollo de Aplicaciones en Red José Rafael Rojano Cáceres http://www.uv.mx/rrojano Web Applications 1 2 Content History (1) History Http CGI Web Tiers ARPANet Email, Ftp, IRC, news Explosive

More information

Transport Layer Security Protocols

Transport Layer Security Protocols SSL/TLS 1 Transport Layer Security Protocols Secure Socket Layer (SSL) Originally designed to by Netscape to secure HTTP Version 2 is being replaced by version 3 Subsequently became Internet Standard known

More information

ATS Test Documentation

ATS Test Documentation ATS Test Documentation Release 0.1 Feifei Cai March 31, 2015 Contents 1 HTTP 3 1.1 Keep-alive................................................ 3 1.2 Connection Timeouts...........................................

More information

ewon-vpn - User Guide Virtual Private Network by ewons

ewon-vpn - User Guide Virtual Private Network by ewons VPN : what is it? A virtual private network (VPN) is a private communications network usually used within a company, or by several different companies or organizations, to communicate over a public network

More information

DEPLOYMENT GUIDE Version 1.2. Deploying F5 with Oracle E-Business Suite 12

DEPLOYMENT GUIDE Version 1.2. Deploying F5 with Oracle E-Business Suite 12 DEPLOYMENT GUIDE Version 1.2 Deploying F5 with Oracle E-Business Suite 12 Table of Contents Table of Contents Introducing the BIG-IP LTM Oracle E-Business Suite 12 configuration Prerequisites and configuration

More information

Lektion 2: Web als Graph / Web als System

Lektion 2: Web als Graph / Web als System Lektion 2: Web als Graph / Web als System Helmar Burkhart Informatik Universität Basel Helmar.Burkhart@... WT-2-1 Lernziele und Inhalt Web als Graph erkennen Grundelemente von sozialen Netzwerken sehen

More information

4.2 Understand Microsoft ASP.NET Web Application Development

4.2 Understand Microsoft ASP.NET Web Application Development L E S S O N 4 4.1 Understand Web Page Development 4.2 Understand Microsoft ASP.NET Web Application Development 4.3 Understand Web Hosting 4.4 Understand Web Services MTA Software Fundamentals 4 Test L

More information

Terminology. Internet Addressing System

Terminology. Internet Addressing System Terminology A local area network (LAN) is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport. The defining characteristics

More information

Chapter 7 Troubleshooting

Chapter 7 Troubleshooting Chapter 7 Troubleshooting This chapter provides troubleshooting tips and information for your ProSafe VPN Firewall 200. After each problem description, instructions are provided to help you diagnose and

More information

1. The Web: HTTP; file transfer: FTP; remote login: Telnet; Network News: NNTP; e-mail: SMTP.

1. The Web: HTTP; file transfer: FTP; remote login: Telnet; Network News: NNTP; e-mail: SMTP. Chapter 2 Review Questions 1. The Web: HTTP; file transfer: FTP; remote login: Telnet; Network News: NNTP; e-mail: SMTP. 2. Network architecture refers to the organization of the communication process

More information

10. Java Servelet. Introduction

10. Java Servelet. Introduction Chapter 10 Java Servlets 227 10. Java Servelet Introduction Java TM Servlet provides Web developers with a simple, consistent mechanism for extending the functionality of a Web server and for accessing

More information

P and FTP Proxy caching Using a Cisco Cache Engine 550 an

P and FTP Proxy caching Using a Cisco Cache Engine 550 an P and FTP Proxy caching Using a Cisco Cache Engine 550 an Table of Contents HTTP and FTP Proxy caching Using a Cisco Cache Engine 550 and a PIX Firewall...1 Introduction...1 Before You Begin...1 Conventions...1

More information

Web Pages. Static Web Pages SHTML

Web Pages. Static Web Pages SHTML 1 Web Pages Htm and Html pages are static Static Web Pages 2 Pages tagged with "shtml" reveal that "Server Side Includes" are being used on the server With SSI a page can contain tags that indicate that

More information

Virtual private network. Network security protocols VPN VPN. Instead of a dedicated data link Packets securely sent over a shared network Internet VPN

Virtual private network. Network security protocols VPN VPN. Instead of a dedicated data link Packets securely sent over a shared network Internet VPN Virtual private network Network security protocols COMP347 2006 Len Hamey Instead of a dedicated data link Packets securely sent over a shared network Internet VPN Public internet Security protocol encrypts

More information

How to Make the Client IP Address Available to the Back-end Server

How to Make the Client IP Address Available to the Back-end Server How to Make the Client IP Address Available to the Back-end Server For Layer 4 - UDP and Layer 4 - TCP services, the actual client IP address is passed to the server in the TCP header. No further configuration

More information

Lab - Observing DNS Resolution

Lab - Observing DNS Resolution Objectives Part 1: Observe the DNS Conversion of a URL to an IP Address Part 2: Observe DNS Lookup Using the Nslookup Command on a Web Site Part 3: Observe DNS Lookup Using the Nslookup Command on Mail

More information

Web application development landscape: technologies and models

Web application development landscape: technologies and models Web application development landscape: technologies and models by Andrea Nicchi Relatore: Prof. Antonio CISTERNINO Controrelatore: Prof. Giuseppe ATTARDI WEB APPLICATION an Information System providing

More information

www.novell.com/documentation SSL VPN Server Guide Access Manager 3.1 SP5 January 2013

www.novell.com/documentation SSL VPN Server Guide Access Manager 3.1 SP5 January 2013 www.novell.com/documentation SSL VPN Server Guide Access Manager 3.1 SP5 January 2013 Legal Notices Novell, Inc., makes no representations or warranties with respect to the contents or use of this documentation,

More information

Introduction to Network Security Lab 1 - Wireshark

Introduction to Network Security Lab 1 - Wireshark Introduction to Network Security Lab 1 - Wireshark Bridges To Computing 1 Introduction: In our last lecture we discussed the Internet the World Wide Web and the Protocols that are used to facilitate communication

More information

Fig (1) (a) Server-side scripting with PHP. (b) Client-side scripting with JavaScript.

Fig (1) (a) Server-side scripting with PHP. (b) Client-side scripting with JavaScript. Client-Side Dynamic Web Page Generation CGI, PHP, JSP, and ASP scripts solve the problem of handling forms and interactions with databases on the server. They can all accept incoming information from forms,

More information

Fundamentals of the Internet 2009/10. 1. Explain meaning the following networking terminologies:

Fundamentals of the Internet 2009/10. 1. Explain meaning the following networking terminologies: Fundamentals of Internet Tutorial Questions (2009) 1. Explain meaning the following networking terminologies: Client/server networking, Coax, twisted pair, protocol, Bit, Byte, Kbps, KBps, MB, KB, MBps,

More information

Firewall Defaults, Public Server Rule, and Secondary WAN IP Address

Firewall Defaults, Public Server Rule, and Secondary WAN IP Address Firewall Defaults, Public Server Rule, and Secondary WAN IP Address This quick start guide provides the firewall defaults and explains how to configure some basic firewall rules for the ProSafe Wireless-N

More information

Application Layer. CMPT371 12-1 Application Layer 1. Required Reading: Chapter 2 of the text book. Outline of Chapter 2

Application Layer. CMPT371 12-1 Application Layer 1. Required Reading: Chapter 2 of the text book. Outline of Chapter 2 CMPT371 12-1 Application Layer 1 Application Layer Required Reading: Chapter 2 of the text book. Outline of Chapter 2 Network applications HTTP, protocol for web application FTP, file transfer protocol

More information

Internet infrastructure

Internet infrastructure Internet infrastructure Prof. dr. ir. André Mariën Web servers HTTP protocol Request/reply operation MIME-like format for both Requests Replies Data model initially: File system like: /.../.../.../x.y

More information