CS 1011
Different Mythologies for connecting to internet
-DSL Lines -Cable Modems -Satellite -Cellular Access **All = sources and destination must be known and use of "addresses"
32 bits
0-255 NOT 256
Why two sets of IP addresses?
1) Built on LAN then WAN 2) Limited Public IP Addresses 3) Apartment buildings (mail box)
Connecting to internet
1) Find source address (URL & DNS) 2) Send request for data 3) Web page sent to destination
How DNS works
1) Get me IP address of a link 2) Record this domain, but not in my cache, i will forward this query to another server. 3) That's in my server, here it is. 4) Thanks for the response, let me cache that as well, if i get more requests for same domain. 5) Thanks IP address, let me establish a connection now 6) Thts in my cache, domain point to IP ____
Acquire website reuqires 2 things
1) Get your Domain Name with ICANN 2) Create or choose web host (sever where we pages reside) for permanent IP and purchase space Purchase Space -Cost vs Services, Platform (Unix vs Microsoft), purpose (commercial vs personal), Private vs attached (sub domains)
Who Controls Internet
1) Internet Engineering Task Force (IETF) 2) World Wide Web Consortium (W3C) 3) Internet Society (ISOC) 4) World Intellectual Property Organization (WIPO) 5) Internet Corporation for Assigned Names and Numbers (ICANN) 6) Internet Assigned Numbers Authority (IANA)
3 areas that made internet the internet
1) Personal Computer 2) Graphic User Interface (GUI) 3) World Wide Web
How Network address Translation Works
1) Router has its own IP address assigned by the ISP 2) Each PC has its own (Private) IP Address assigned by the router 3) When a PC goes on the net it appears as if it has the router's (public) IP Address 4) All the PCs on the network have the same (public) IP Address - the request goes from PC to router out to the net -Returns go to the router and then the router sends them to specific PC using NAT (Network Address Translation:MAC address routing)
2004
10th anniversary of Web's general availability to public. Newest browser is Firefox by Mozilla Apple Computers Ipod pocket sized mp3 music player Facebook started collecting friends Podcasting commenced Flickr image hosting website opens Mass use of voice over internet protocol -VoIP begins.
Search Engines
1993 - Jerry's Guide to WWW (Renamed Yahoo) - manual entries of websites 1998- Google (based on misspelling) - web crawlers to automatically add sites.
Max Packet length
2^16-1 = 65,535 bytes
2000
300,000 miles of fiber and cable, UUNET owned an estimated 30% of the internet infrastructure Other = AT&T, GTE, Global Crossing, Qwest, PSINet Control of Internet infrastructure gave companies power to charge smaller ISP for operating network access points where ISP traded packets with each other.
2000
750,000 commercial sites on World wide web
Markup Languages
A markup language is a computer language that use tags to define elements within a document It is human readable (Scribe, GML, TeX)
Social Impact
A person may now carry out a conversation with another user without the constraint of being expected to reply within a short amount of time and without needing to set time to aide for engagement.
IP Payload
Actual stuff the user needs to transport
Host Computer Address (IP Address)
Address on the internet of that specific computer. Hard to remember, use. Introduced a concept of naming address
Apple in 1990s
Almost disappeared Black and white interface- limited access to the net
World Intellectual Property Organization (WIPO)
An agency of the UN whose purpose is to develop international standards to protect the rights of intellectual property holders (name of domains)
Host Computer
Any computer that stores the files you want access to
2015
Apple released iwatch, wearable tech
2007
Apple released the Iphone multimedia and Internet smartphone - web goes mobile
How SMS Gateway Works
Application server -> Http Call -> (SMS Gateway) -> Telecom -> (SMS) -> Cellphone Cell phones are always sending and receiving through signals even when the phone isnt in use. The signals are sent and received from a cell phone tower or control channel. When message sent, goes through closest tower then SMS center. SMSC recceive message, sends to appropriate tower closest to location.
Mail User Agent (MUA)
Application the originating sender uses to compose and read email
Tim Berners Lee
Brought HyperText, URL, Markup languages, GUI together to create World Wide Web
Advantages of IMAP
Can be accessed in multiple locations or computers. Can be accessed by multiple users as a group email account.
1995
Commercial ISP Regional ISP Dial-up Access
Logical Address IPv4
Comprises of four sets of numbers separated by periods IPv6 = 6 sets
Security concerns
Consumer SMS should not be used for confidential communication. The contents of common SMS are known to the network oprator's systems and personnel.
IP packet header
Contains miscellaneous information to help the packet on its way. - 20 and 60 bytes length. Has Destination address, source address, total length of packet, version of IP used.
Internet
Created in 1990 Mostly a file transfer mechanism Email communication Used in University and Business
Overwhelming response to Altair led to
Creation of Microsoft (1975) Creation of Apple II (1977) Creation of IBM PC (1981)
1991 Berners Lee
Write program goes through a file line by line to find combinations of processing (formatting) tags and text. Then combined HyperText jumping with markup tags to create a standard that each file has to adhere to so his program will be able to process and display formatted text and links.
Advantages of POP
allow the user to keep a copy of their email downloaded on their computer. You free up server space
Disadvantages of POP
once your message is removed from the server by one computer, you cannot access it from another computer.
Computer
reads files and loads those 1s and 0s into a program
Texting Etiquette
Refers to what is considered appropriate texting behavior. Provided a venue for participatory culture
Disadvantages of IMAP
Resides on server at all times, which takes away from storage space on server. Cannot download email files to computer.
Internet Corporation for Assigned Names and Numbers (ICANN)
Responsible for managing Domain Names. Established in 1988, non profit from US Government. Different from other in that web site owners MUST register with an ICANN approved registrar
Static IP Address
Router has the same address every time
SMS job
SMS formats the message in a way that it is able to travel to and from the town, and still be received by the cell phone. SMS also sends data associated with the message, such as length of message, destionation, or some time stamp.
Internet Engineering Task Force (IETF)
Self organized group that makes technical contributions to the engineering of the internet and its technologies. Is the main body that develops internet standards
Email: Step A
Sender Creates and sends an email: The originating sender creates an email in their mail user agent (MUA) - Outlook
Email: Step B
Sender's MDA/MTA routes the email The sender's MUA transfer the email to a mail delivery agent (MDA) The MDA/MTA accepts the email, routes it to local mailboxes or forwards it if it isnt' locally addressed
Protocols
Set of rules and standards required to accomplish some goal or activity
2000s
Seventy million computers connected to internet.
1990
Shift to home business computers, connected together, and networks. Still boring, internet only has screen of text. Good at exchanging information Virtually very boring
SMS
Short message service, or texting is method of communication between cellphones or from PC. Short part comes from maximum of 160 characteristics (Letters, numbers, or symbols) Developed by Franco-German GSM cooperation in 1984 by Friedhelm Hillebrand and Bernard Ghillebaert.
Today
Smaller regional + local ISP have been able to compete with national ISPS by offering better service Lack reach and brand awanress but has value and better ecommerce + web design.
!990's
Technology had to be in place Graphic users Interface - Windows and Macintosh, Mouse High speed connections - arpanet high speed backbone Modem - mechanism allowing common access to the net. First dedicated destinations, compuserve:AOL:Usenets. Then IP providers allow direct access - Execulink, Rogers, Bell
The Perform Storm
Technology, commerce, Acceptance
Delivery
The email makes it past the hazards of the spam trap filter and is accepted for delivery by the receiver's MTA. The MTA calls a local MDA to deliver the mail to the correct mailbox, where it will sit until it is retrived by the recipient's MUA.
Mosaic
The first browser which became popularly available to take advantage of HTML Transmission was slow as a wet week. And really didnt handle downloading pictures well End of 1994, a million browser copies in use.
Email: Step C
The network cloud may encompass a multitude of mail servers, DNS servers, routers. In private emails, this would be the IP server
Disruptive Technology
The web starts changing how we live Small changes leading to large effects
Firewalls, Spam, and Virus Filters
These filters test to see if the message qualifies as spam or malware. If the message contains malware, the file is usually quarantined and the sender is notified. If the message is identified as spam, it will probably be deleted without notifying the sender.
Domain Name System (DNS)
Translates domain names which can be easily memorized by humans to the numerical IP addresses requested
TCP/IP
Transmission Control Protocol Internet Protocol
IMAP
Use IMAP if ou want to access your email from multiple computers or locations. It stores mail on email servers
POP3
Use POP if you access your email from one computer only. It stores email on the users computer.
1990 - GUI
Wanted to make internet more aesthetic Companies like Compuserve and AOL began developing GUI. GUI added a bit of color and layout but still boring IBM personal computers began to adopt Windows Interface.
Uniform Resource Locator (URL)
Where you could click on a word. Hyperlinks
HyperText
Where you could click on word It would tkae you somewhere else(Hyperlinks)
WIFI VS Cellular
Wifi = Sent through computer Celluluar : sent through cell receptors
2001
Wiki opened Google answered more than 100 million searches per day Apple released first ipod The file sharing service Kazaa founded
FTP
File transfer protocol. provides a way to transfer files from one computer to another over any TCP/IP Network, such as LAN. Can be explicit or implicit Explicit - OWL, filezilla, FTP Client Implicit - Cloud, file hosting, dropbox, iCloud
Email: Step F
Firewalls, Spam, and Virus Filters. The transfer process described in the last step is somewhat simplified. An email may be transferred to more than one MTA within a network cloud and is likely to be passed to at least one firewall before it reaches it destination. An email encountering a firewall may be tested by spam and virus filters before it is allowed to pass insdie the firewall.
Crash of 2000
First time internet affected outside foreces
Mail Delivery Agent (MDA)
Forwards the email to an Mail Transfer Agent (MTA) and it enters the first of a series of "network clouds" labeled as a "company network" cloud
Before Internet Providers
Get internet through required university of government account
2008
Google releases chrome browser - Introduced web based applications Replaced traditional installed software
ipconfig
Host Name Wireless Vs Ethernet Physical Address IPv4 Address Default Gateway DNS Server
1988
IBM, MCI, and Merit work with NSF to create the internet backbone T3 lines (45Mbps)
Dynamic IP Address
ISP assigns IP address every time you connect to the internet Maintains this IP during the entire session
Web 2.0
Interactive computing. Commercial Existing markets - new business models, online shopping, banking, entertainment.
World Wide Web Consortium (W3c)
International organization that establishes specifications and standards for the web web site owners, designers, and ocmpanies that develop hardware and software for the web DO `NOT have to follow their specifications. but most do to ensure compatibility.
Internet Society (ISOC)
International organization that works with the IETF to develop standards that allow people all over the world to have access to the internet
IMAP
Internet Message Access Protocol With the IMAP protocol, email is mirrored or synched with the mail on the server. You never download the messages to your computer and need to be connected to the internet at all times to manage your email. If you delete a message, it gets delete from server. Email management takes place all on the server. Can access from many different computers
Web 1.0
Internet was a collections of data. Flat look up concepts. Only real interaction - user groups and email.
1994
Introduction of NAP Quickly became clogged 4 sites became the world ISP
Microsoft in 1990
Late to the game. Ignored the web - no native browser IE released after widespread adoption of Netscape
MAC Address
Layer 2 - Data link layer
LAN IP
Layer 3 - network layer
Regional ISP
Lease from larger companies Rogers from UUNET and Bell leases from AT&T Local ISP lease from regional TekSavvy leases from Rogers
Email: Step E
MTA to MTA Transfer When transferring an email, the sending MTA handles all aspects of mail delivery until the message has been either accepted or rejected by the receiving MTA. As the email clears the queue, it enters the internet network cloud, where it is routed along a host-to-host chain of servers.
Internet Protocol
Machines on the internet implement IP Allow short messages - packets to be quickly routed
2011
Memory and storage prices continue to drop, storage starts to move from local to internet. Distributed programming is introduced in an enterprise environment - MS Office Concept of Cloud introduced
2003
More than 3 billion web pages New browsers include safari, Amaya, Camino, Lynx, Opera, Phoenix Virtual world second life was born MySpace started Skype voice calling over the internet begins Apple introduces the online music services - Itunes
2005
More than 8 billion web pages Online tech is 2/3 american homes. 3/4 do online shopping 12.5h a week. TV views decline Youtube began storing and retrieving videos Google Earth is a virtual globe, map and geographical internet site.
Access to Internet
Must have agreement with ISP and pay. Either per time, per amount, or combintion.
1987
National Science Foundation (NSF) created first high speed backbone NSFNET Connected 170 smaller networks T1 lines (1.544Mbps)
The Web Server
Nothing more than a computer Stores files just like computer Comprises of a farm (multiple computers for different tasks) Has own public IP Address - usually static
Domain Name System (DNS)
Nothing more than a corresponding list
Internet Assigned Numbers Authority (IANA)
Operated by ICANN Manages the IP addresses Manages DNS table operations.
WorldWide:
Over 30,000 ISP Canada has 220 ISP Ontario has 142 London has 43
Key differences
POP - one user, one computer IMAP - multiple users, different computers POP - Downloads mail to computer IMAP - stores mail on server POP - organize mail in orders on user compuers iMAP - Folders can be organized on the server size.
POP
Post office Protocol Email is stored on server until user downloads their mail using a mail client. At that point, the mail is typically removed from server. Created so people could go online, download their mail and sign off allowing the users to read offline.
Media Transfer Agent (MTA)
Each MTA in the internet network cloud needs to "stop and ask directions" from the Domain Name System (DNS) in order to identify the next MTA in the delivery chain. The exact route depends partly on server availability and mostly on which MTA can be found to accept email for the domain specified in the address.
Email: Step D
Email Queue The email in the diagram is addressed to someone at another internet provider: so it enters an email queue with other outgoing email messages
