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What is a Network Operating System (NOS)?

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What is a Network Operating System (NOS)?

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Coordinates multiple computers across a network

*Peer-to-Peer
*Client/Server

-Nearly all modern networks are a combination of both of these.

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Allows the Operating System to share resources located on their computers and to access shared resources on other computers.

Designed for small to medium local area networks

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Twisted Pair has 2 types:
1. Shielded
2. Unshielded

Unshielded UTP is the most popular and best option for schools. It has a standard connector (RJ-45) connector, which looks much like a telephone connector.

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The configuration of cables, computers, and other peripherals
*Linear Bus
*Star
*Tree (expanded star)

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Protocols - Set of rules that govern communications on a network

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Protocols - Set of rules that govern communications on a network

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*Computers must be able to communicate on a network, so they must have a common operating system.

*OSI - Open Systems Interconnection
-Common Protocols: HTTP, FTP, SMTP, DNS, Telnet

*There are 4 layers :
1. Ethernet (Physical/Data Link Layers)
2. IP/IPX (Network Layer)
3. TCP/SPX (Transport Layer)
4. HTTP, FTP, Telnet, SMTP, and DNS (Combined Session/presentation/application layers)

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Ethernet Layers (Physical/Data Link Layers)

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Ethernet Layers (Physical/Data Link Layers)

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Hardware elements - cables, repeaters, network interface cards (CSMA/CD) - Carrier Service Multiple Access/Collision Detection)

*Ethernet - original standard developed in 1983 with max speed of 10 Mbps

*Current standards use a twisted pair wire
Common Types - 10BaseT, 100BaseT, 1000BaseT
(Baseband means it has full control of the wire on a single frequency)
"T" stands for Twisted Pair
"Fiber" can also be used (ex: 10BaseFL)

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Category 5 twisted pair or fiber optic cables
*100BaseT - 100Mbps over 2 pair category 5 or better UTP cable
*100Base FX - 100Mbps over fiber cable
*100BaseSX - 100Mbps over multimode fiber cable
*100BaseBX - 100Mbps over single mode fiber cable

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Consists of two or more computers linked together to share resources (printers/CDs), exchange files, or allow electronic communications. Connected by cables, telephone lines, radio waves
Types include:
LAN - Local Area Networks (common)
WAN - Wide Area Network (common)
MAN - Metropolitan Area Network
WLAN - Wireless LAN
WWAN - Wireless WAN

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Includes all computers, peripherals, interface cards, and other equipment needed to perform data-processing and communications within the network.

*Wireless adapter
*Switches
*Repeaters
*Bridges
*Routers
*Firewalls

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Gigabit Ethernet - has transmission speed of 10 Gigabit Ethernet (10,000Mbps) and 100 Gigabit Ethernet (100,000Mbps)

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Gigabit Ethernet - has transmission speed of 10 Gigabit Ethernet (10,000Mbps) and 100 Gigabit Ethernet (100,000Mbps)

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IP & IPX (Network Layer) - in charge of routing network messages (data) from one computer to another.
- Are the leading protocols for most networks

MAC - Media Access Control - address assigned to a network card (fixed and cannot be changed) for devices on the network

TCP & SPX (Transport Layer) - by far the most popular protocol at the transport level

HTTP, FTP, SMTP, DNS (Session/Presentation/Application Layers)
*DNS - Domain Name System - translates network address (IP Address) into human terms
*DHCP - Dynamic Host Configuration - automatically assigns Internet addresses to computers and users
*FTP - File Transfer Protocol - transfers and manipulates files on the internet
*HTTP - Hyper Text Transfer Protocol - Internet-based protocol for webpages on the internet
*IMAP -Internet Message Access Protocol for email messages
*IRC - Internet Relay Chat - a protocol used for Internet chat and other communications
*POP3 - Post Office Protocol Version 3 - used by email clients to retrieve messages from remote servers
SMTP - Simple Mail Transfer Protocol - A protocol for email messages on the Internet

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LAN - A network confined to a relatively small area such as a writing lab, school, or building.

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LAN - A network confined to a relatively small area such as a writing lab, school, or building.

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* Computers connected are considered servers or workstations, which run continuously to provide "services" to other computers on the network. (printing, faxing, software hosting, file storage, messaging, data storage, retrieval, complete access control - security)

* Workstations - desktops, computers, keyboards, mouse, display, laptops, iPads, iPhones

*Servers tend to be more powerful than workstations.

*WAPs (wireless access points) provide a bridge between computers and networks.

*Cable connections remain the fastest

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*Connects networks in larger geographic areas such as the US to the world.

*Complicated - using multiplexers, bridges, routers, global communication networks (www)

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Advantages of Installing a School Network

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Advantages of Installing a School Network

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1. User Access Control
2. Information Storing and Sharing
3. Connections
4. Services
5. Internet
6. Computing Resources
7. Flexible Access
8. Workgroup Computing

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Disadvantages of Installing a School Network

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Disadvantages of Installing a School Network

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1. Expensive to Install
2. Requires Administrative Time
3. Servers Fail
4. Cables May Break
5. Security and Compliance - important and expensive

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Resources are controlled by the file server

Popular Peer-to-Peer and Client/Server Network Operating Systems include:
*Macintosh OSX
*Microsoft Windows Server
*UNIX/Linux