CCNA 1 v3.0 Module 2 Networking Fundamentals

Objectives

Data Networks

What is a Network?

At its simplest a network is two or more devices which are connected together using some kind of “transmission medium” A very simple network may be one desktop connected to a laptop

Network History

Network History continued

Networking Devices

Network Topology

Network Protocols

Local-area Networks (LANs)

Wide-area Networks (WANs)

Metropolitan-Area Network (MANs)

Storage-Area Networks (SANS)

Virtual Private Networks (VPNs)

The following are the three main types of VPNs:

Access VPNs – Access VPNs provide remote access to a mobile worker and small office/home office (SOHO) to the headquarters of the Intranet or Extranet over a shared infrastructure. Access VPNs use analog, dialup, ISDN, digital subscriber line (DSL), mobile IP, and cable technologies to securely connect mobile users, telecommuters, and branch offices. Intranet VPNs – Intranet VPNs link regional and remote offices to the headquarters of the internal network over a shared infrastructure using dedicated connections. Intranet VPNs differ from Extranet VPNs in that they allow access only to the employees of the enterprise. Extranet VPNs – Extranet VPNs link business partners to the headquarters of the network over a shared infrastructure using dedicated connections. Extranet VPNs differ from Intranet VPNs in that they allow access to users outside the enterprise.

Benefits of VPNs

Intranet and Extranet VPN

Importance of Bandwidth

Bandwidth Pipe Analogy

Bandwidth Highway Analogy

Bandwidth Measurements

Bandwidth Limitations

Bandwidth Throughput

Digital Transfer Calculation

Digital versus Analog

Using Layers to Analyze Problems

Communication

All of the different types of network face the problem of interconnectionComputers are made by different manufacturers to many different standardsIn order for them to communicate they must adopt the same rules

Open Systems Interconnection

ISO OSI Reference modelThe International Standards Organisation set out a system for Open Systems InterconnectionThis lays out the way that systems should communicate with each otherThe OSI model has 7 layers

Advantages

• Breaks network communication into smaller, simpler parts

• Makes learning easier. • Lets people and companies specialise• It allows different types of network hardware

and software to communicate with each other. • It prevents changes in one layer from affecting

the other layers, so that they can develop more quickly.

OSI Layers

OSI Layers

OSI Layers

OSI Layers

OSI Layers

OSI Layers

•Provides connectivity and path selection between two host

•Provides Logical address

•No error correction, best effort delivery.

OSI Layers

TCP/IP Model

Data Encapsulation

OSI Reference Model

OSI Reference Model

Summary