Networking and the Internet Flashcards
Network Classifications
Scope
-Personal area network PAN
-Local area network LAN
-Metropolitan are network MAN
-Wide area network WAN
Topology
-Bus (ethernet)
-Star (wired/wireless, Networks with central active devices, HUB/Switch/Access Point
Protocols
CSMA/CD
-Carrier Sense Multiple Access/Collision Detector
-Used in Ethernet
-Silent bus provides right to introduce new messages
CSMA/CA
-Carrier Sense Multiple Access/Collision Avoidence
-Used in Wi-Fi
-Hidden terminal problem
Connecting Networks
Repeater : Extends a network
Bridge : Connects two compatible networks
Switch : Connects several compatible networks
Router : Connects two incompatible networks
Internet : Network of networks —> InterConnected Networks
Inter-process Communication
Client-server
-One server, many clients
-Server must execute continuously
-Client initiates communication
Peer-to-peer (P2P)
-Two processes communicate as equals
-Peer processes can be short-lived
Distributed Systems
-Cluster computing
-Grid computing
-Cloud computing
+Amazon’s Elastic Compute Cloud
+Google Drive
The Internet
An internet that spans the world
-Amacı yerel hatalardan çökmeyecek bi ağ geliştirmek
Internet Architecture
Internet Service Provider (ISP)
-Tier-1
-Tier-2
Access or Tier-3 ISP : Provides connectivity to the internet
-Hot spot(wireless)
-Telephone lines
-Cable/Satellite systems DSL
-Fiber optics
Basic Components of an ISP
Firewall
Router
Web Server + E-mail Server + AAA Server + DNS Server
Modems
Dotted Decimal Notation
192.168.1.1
Boundaires of IPv4 Address Classes
0.0.0.0. to 255.255.255
New Dimension IPv6
128 bit
IPv4 x 2^96 Size
ICANN
Internet Corporation for Assigned Names & Numbers (ICANN)
-ICANN allocates IP addresses to ISPs
-ISPs assign those addresses within their regions
-ICANN oversees the registration of domains and domain names
Early Internet Applications
NNTP : Network News Transfer Protocol
FTP : File Transfer Protocol
SSH : Telnet and Secure Shell
HTTP : Hypertext Transfer Protocol
email : Electronic Mail
-via POP3 or IMAP
Basic Terms for Mail Systems
SMTP : Simple Mail Transfer Protocol
MIME : Multipurpose Internet Mail Extension
POP : Post Office Protocol
IMAP : Internet Mail Access Protocol
More Recent Applications
-Voice Over IP (VoIP)
-Internet Multimedia Streaming
+N-unicast
+Multicast
+On-demand streaming
+Content delivery networks (CDNs)
World Wide Web
-Hyprtext combines internet technology with concept of linked-documents ++Embeds hyperlinks to other documents
-Browsers present materials to the user
-Webservers provide access to documents
-Documents are identified by URLs and transferred using HTTP
XML
Extensible Markup Language
-A language for constructing markup languages similar to HTML
-A descendant of SGML (Standart Generalized Markup Language)
-Opens door to a World Wide Semantic Web
Client Side vs Server Side
Client-side activites
-Java Script
-MAcromedia Flash (Outdated)
Server-side activites
-Common Gateway Interface (CGI)
-Servlets
-JavaServer Pages JSP/ Active Server Pages ASP
-PHP
Protocol for Internet : TCP/IP Protocol Suite
Transmission Control Protocol/ Internet Protocol
-Protocol developed for use on internet
-Researchers who developed TCP/IP also developed the internet architecture
Internet Softwre Layers
Application : Constructs message with address
Transport : Chops message into packets
Network : Handles routing through the Internet
Link (Data Link) : Handles actual transmission of packets
TCP/IP Protocol Suite Components
Transport Layer
-Transmission Control Protocol (TCP) **relaible
-User Datagram Protocol (UDP) **efficient
Network (Internet) Layer
-Internet Protocol (IP)
+IPv4
+IPv6
Common terms used for messages
Packet : Data at Internet Layer and above
Frame : Data at Network Interface Layer
Datagram : Data between routers
Port Number : Numbers assigned to each protocol
Security
Attacks
-Malware (viruses, worms, Trojan horses, spyware, phishing software)
-Denial of service (DoS)
-Spam
Protection
-Firewall
-Spam filters
-Proxy Servers
-Antivirus software
Encryption
HTTPS and SSL
Public-key Encryption
-Public key : Used to encrypt messages
-Private key : Used to decrypt messages
Certificates and Digital Signatures
Certificate authorities