6.7: Summary

6.1. Introduction to Networking and Communication

The Internet (Interconnected Network of Networks) started in 1969, as ARPANET, in the United States. And it had grown so much, that it has more than 6 billion users world wide. The Internet was made possible with the creation of the Transmission Control Protocol / Internet Protocol (TCP/IP), which allowed all networks to be able to communicate. 

The World Wide Web (WWW) project was created by Tim Berners-Lee in 1990, allowing (through HTML) the use of hypertext in documents, which prompted what is now called "web navigation".

The first browser was the "Mosaic", which was later replaced by the first commercial browser: "Netscape Navigator", when the Internet was released to the general public in 1994.

6.2. Network Basics

6.3. Providing Resources in a Network

Let us see three types of computer networks:

1. Geographical area networks
   • Body area network (BAN) 
   • Personal area network (PAN) 
   • Local area network (LAN) 
   • Metropolitan area network (MAN) 
   • Wide area network (WAN)
   • Cloud network 
2. Access level networks
   • Internet
   • Intranet
   • Extranet
3. Special purpose networks

   • WLAN (Wireless LAN)

   • SAN (Storage Area Network)

   • VPN (Virtual Private Network)

A client-server network is a computing model in which multiple clients connect to a central server to access resources, such as files, applications, and data.

The network framework contains three classes of network segments:

• Devices
  • End devices: either the source or destination of a message transmitted over the network
  • Intermediary Network devices: act as intermediaries between devices
• Media
  • Metallic cable
  • Fiber optic cable 
  • Wireless transmission 
• Services

Network topology refers to the physical and logical arrangement of nodes and connections in a computer network, which governs how data flows between devices.

There are two types of Topology diagrams:

• Physical topology diagrams
• Logical topology diagrams

Types of Network topologies: 

• Point-to-point
• Bus
• Ring
• Mesh
• Star
• Tree
• Hybrid

6.4. Internet Connections

Residential and Home Office clients are served ⇒ Internet Service Providers. Business and Commercial clients are served ⇒ Specialist Organizations 

Regular connection choices for Home and Small Office users:

• Dial-up telephone 
• DSL
• Cable
• Fiber Optic
• Cellular
• Satellite

Business connection options include:

• Dedicated Leased Line (DLL)
• Ethernet WAN
• DSL
• Satellite

6.5. Network Trends

Each day we find new trends in technology, and in Networks. Here are some of those trends:

• Bring Your Own Device 
• Online collaboration
• Video communications
• Cloud computing
• Home trends
• Powerline Networks
• Wireless broadband and Wireless ISP
• Cellphone platforms and roaming services 

6.6. Network Security

Network security is an indispensable piece of computer networking today, whether or not the network is restricted to a home domain with a solitary connection with the Internet or as extensive as an organization with many users.

The most widely recognized threats (internal or external) to networks include:

• Viruses, worms, and Trojan horses
• Spyware and adware 
• Hacker attacks
• Denial of service attacks - DOS
• Data interception and theft 
• Identity theft

No single arrangement can shield the network from the many threats that exist. Consequently, security ought to be implemented in various layers, utilizing more than one security arrangement.

Home and Small Office Networks Solutions:

• Antivirus and antispyware
• Firewall filtering

Business and Corporate Networks Solutions:

• Dedicated firewall systems
• Access control lists (ACL)
• Intrusion prevention systems (IPS)
• Virtual Private Networks (VPN)

The security arrangement executed must be versatile to the developing and changing trends of the network. The study of network security dangers and relief strategies begins with a concise understanding of the underlying switching and routing infrastructure utilized to organize network services.