The Computer Revolution/Networks/Components

Network Backbones
Backbones are the basic infrastructure of the internet. They are high speed lines that directly connect large hubs, companies and academic institutes. Typically trunk line backbones are made of fibre optic cables. Many of these fibre optic cables are bundled together to increase capacity. The rating system for fibre optic cables is designated with OC for optical carrier. For example an OC-3 has a transmitting capacity of 155Mbps whereas an OC-48 can transmit 2488Mbps (2.488Gbps). An OC-48 is about 44,430 times faster than a standard 56Kbps modem still available today. This huge network of backbones between countries governments, educational institutions, research institutions and companies operate their own backbones which interconnect. The entire network is a gigantic agreement between these institutions sprawling around the world allowing the freedom of intercommunication.

Network Operating System
A Network Operating System (NOS) is software that serves the following three purposes:


 * 1) It controls a network and the messages (packets) and queues it receives
 * 2) It controls access to network resources (e.g., files) by multiple users
 * 3) It provides for certain administrative functions, such as security

A NOS is not the same as Windows XP (a networking tool provided by an existing operating system), as an example. A networking operating system is an OS that has been written to keep a network running at peak performance.

A NOS is most often used with LANs (local area networks) and WANs (wide area networks), but might also be used in conjunction with larger network systems.

NOS is an operating system that also has special functions for connecting computers and devices into a LAN or Inter-networking. Some of the more common NOS for DOS and Windows systems are Novell Netware, Windows NT and 2000, Sun Solaris and IBM OS/2. The Cisco Internet Operating System (IOS) is also a NOS that specializes in the Internet working capabilities of network devices.

Some of the features of the Network Operating System are:


 * 1) Basic operating system features such as support for processors, protocols, automatic hardware detection, and multi-processing of applications
 * 2) Security features that include authentication, logon restriction and access control
 * 3) Provide name and directory services
 * 4) Provide other services, such as file, print, web, back-up and replication
 * 5) Support Internet working (e.g., routing, WAN ports)
 * 6) Support and user management for logging off and on (remote access), system management, administration and auditing tools with graphic interfaces
 * 7) Clustering capabilities for fault tolerant and high availability systems