Chapter One

Some Raw Basics of Networking

Objectives

• Introduce some basic concepts

• Learn some new vocabulary

• Get our first glimpse of some networking hardware

• Be introduced to the concept of topology

• Learn about some protocols

Reasons to Set Up a Network

• Communications

• Sharing files and peripherals

• Security

• Software management

Some Basic Networking Hardware

• Transceivers• Repeaters• Hubs

– Passive – Active

• Switches• Bridges• Routers

What is a network?

• Any two devices that can interconnect make up a basic network.

• Local area networks (LAN) serve a contained geographic location.

• Wide area networks (WAN) interconnect multiple LANs over a dispersed geographic range.

The Basic Components of Infrastructure

• Media– Bounded– Unbounded

• Topology

• Protocols

• Standards

Bounded Media

• Twisted pair

• Coaxial

• Fiber optics

Unbounded Media

• Infrared

• Radio

• Laser

• Microwave

Twisted Pair

• Shielded twisted pair (STP)

• Unshielded twisted pair (UTP)

• Rated by category

• Terminated by RG-45 connectors

• Generally limited to 100M runs

Coaxial• Thinnet

– RG-58– Good for 180M runs– Limited to 10Mb/s bandwidth– Terminated by BNC connectors

• Thicknet– RG-8– Good for 500M runs– 10Mb/s bandwidth– Uses vampire clamps

Fiber Optics

• A wide variety of connectors

• Runs of 2KM to much, much longer distances

• Speeds of 100Mb/s to several Gb/s

Network Topologies

• Bus

• Ring

• Star

• Hybrid

• Mesh

Bus Networks

• They generally use coaxial cable (obsolete).

• Computers hook up in single file.

• Each end of the line must be terminated.

• If one computer goes down unexpectedly, the entire network can be brought down.

Ring Networks

• While generally set up in a virtual circle, a device called a multi-station access unit (MAU) puts the network into a physical star.– Token ring and FDDI are two types of

networks that use the ring topology.

Star Networks

• Patch cords hook up the devices into a central hub or switch.– Provides centralized management– Facilitates managing connections

• It is the primary topology used by Ethernet.

Hybrid Networks

• Interconnects multiple topologies into a single network– Three rings might be hooked together in a bus

• Can be a solution to large networks spread across multiple floors in a building

Mesh Networks

• Each device has a direct connection to every other device on the network.

• They are used to interconnect multiple servers in a cluster.

• The internal wiring of a router is basically a mesh network.

The 802 Committees (1 of 4)

• They were created in February of 1980 (hence the 802).

• Each committee is assigned oversight of a specific networking technology.

• Not all 802 Committees are currently active.

802.0 SEC

802.1High Level Interface (HILI) Working Group (frequently called the Internetworking Standards)

802.2 Logical Link Control (LLC) Working Group

802.3CSMA/CD Working Group (frequently called the Ethernet Standards)

802.4 Token Bus Working Group (currently on permanent hiatus)

802.5 Token Ring Working Group (currently on permanent hiatus)

The 802 Committees (2 of 4)

802.6 Metropolitan Area Network (MAN) Working Group (currently on permanent hiatus)

802.7Broadband Technical Adv. Group (BBTAG)

802.8 Fiber Optics Technical Adv. Group (FOTAG) (permanently disbanded)

802.9 Integrated Services LAN (ISLAN) Working Group (currently on permanent hiatus)

802.10Standard for Interoperable LAN Security (SILS) Working Group

The 802 Committees (3 of 4)

802.11 Wireless LAN (WLAN) Working Group

802.12Demand Priority Working Group (currently on permanent hiatus)

802.14Cable-TV Based Broadband Communication Network Working Group (permanently disbanded)

802.15 Wireless Personal Area Network (WPAN) Working Group

802.16 Broadband Wireless Access (BBWA) Working Group

802.17 RPRSG Resilient Packet Ring Study Group (RPRSG)

The 802 Committees (4 of 4)

The Hardware Protocols• CSMA/CD

– Ethernet– Carrier sense, multiple access/collision detection

• FDDI– Fiber distributed data interface– CDDI (copper DDI)

• A copper-based standard

• Token ring• CSMA/CA

– Carrier sense multiple access/collision avoidance