Portal:Computer networks

Welcome to the Department of Computer Networks!

Also Part of Engineering and Technology

Educational level: this is a tertiary (university) resource.

Type classification: this resource is a collection of other resources.

Completion status: Been started, but most of the work is still to be done.

Subject classification: this is an information technology resource.

Computer networking is the scientific and engineering discipline concerned with communication between computer systems. Such networks involve at least two devices capable of being networked with at least one usually being a computer. The devices can be separated by a few meters (e.g. via Bluetooth) or thousands of kilometers (e.g. via the Internet). Computer networking is sometimes considered a sub-discipline of telecommunications.

Computer networking can be examined from either the 7 layer OSI Model, or the 4 layer TCP/IP Model

Introduction

Networking is the practice of enabling and harnessing the transmission of data between computer systems. A simple analogy of a data network is two tin cans connected by a simple string. As in the analogy, the following holds true for actual data network implementations as well:

The network exists merely as a medium for communications across it
A protocol of some form is needed to initiate and carry on conversations (this is not intrinsic to the network itself)
The same protocol (a spoken language) can also be used with different media for the same purpose; different networks have different advantages and uses

A network may require one engineer to design it, another to build it, and yet another to administer it. The skills needed by each are related, but not necessarily dependent; hence, Networking is interdisciplinary. Networking developed within the discipline of Computer Science, but an extensive background in Computer Science is not necessary to study or even practice Networking. A Network Engineer works with data networks in some form, but the scope of that work and the skills required may be as diverse - even from one job to the next - as those of any scientist.

Topics

Networking is the practice of enabling and harnessing the transmission of data from one computer system to another. The TCP/IP model is used in presenting the following topics.

OSI Seven Layer Model

The alternative OSI layer can be studied here.

Layer 7, the Application layer, provides service directly related to the applications. Those services vary on applications.
Layer 6, the Presentation layer, format the data to look like common for all applications
Layer 5, the Session Layer, establishes a connection between two nodes. Deals with whether the connection is full duplex, half duplex etc.
Layer 4, Transport layer, handles and delivers data, whenever it is connection-oriented or connectionless. It includes some flow control issues.
Layer 3, Network Layer, establishes the connection between two nodes, using the IP addressing.
Layer 2, the Data Link Layer, frames data and provides low-level flow control
Layer 1, Physical layer, transmits low bitstreams (data), deals with electrical signalling, cabling and hardware interface

Each topic includes an outline, suggested activities and links to useful resources. They are constructed for self-study, but should be adaptable to a group environment.

Courses

External Resources

Wikibooks has more on the topic of Computer networks.