TC 361 Data NetworkingTest Review

Network Cabling

• UTP• Generally used in

Ethernet installations– Cat 3 10 Mbps– Cat 5 100 Mbps– Cat 5e 1000 Mbps

– 100M length

Network Cabling

• Coax– Has a core made of

copper. – ThinNet

• BNC connector• 183M

– ThickNet• Vampire Taps (MAU)• 500M

Network Cabling Cont.

• Fiber Optic– Single Mode

• Laser

– Multi Mode• LED• Multiple Signals

– 2KM Length– ST, SC connector– Not susceptible to EM

interference

Network Communication

• Packet– Variable Length– Contains Header and Trailer, CRC, and data– Data is divided into packets for ease of

transmission

• Cell– Fixed Length

• MAC address

OSI

Network Types

• Ethernet– Carrier Sense Multiple

Access/Collision Detection (CSMA/CD)

• Contention network• Simultaneous

transmissions cause collisions

– 10-1000 Mbps– 802.3– Physcial Media

• Coaxial (ThickNet, ThinNet), UTP, STP, Fiber

• Token Ring– 802.5– 4-100 Mbps– Physical Media

• Proprietary IBM standard

Network Types Cont.

• FDDI– Fiber Distributed Data

Interface – Token Passing– Can work in two

counter-rotating rings. – Can be used as a

backbone network

• ATM– Asych Transfer Mode– Data is broken into

fixed cells– Ideal for

voice/video/data– Transmits 53 byte

cells.

Network Types Cont.

• Wireless– 802.11b

• 11 Mbps • 2.4 GHZ

– 802.11a• 54 Mbps• 5GHz

– 802.11g• 54 Mbps• 2.4 GHz• Compatible with 802.11b

Network Topologies

• Star– Used in Ethernet. – Computers connected to a central unit.

• Bus– Computers are connected in a series– A break in the cable will cause the entire segment to collapse. – Must use terminators

• Ring– Passes a token (packet) from one segment to another– Can have the physical topology of a star network.

• Mesh– Every computer is connected to one another– Most expensive and reliable technology

Network Hardware

• Hub– Used to connect

computers together– Repeats packets to all

computers on the hub– Token Ring: Multi

Station Access Unit

• Switch– Used to connect

computers together– Repeats packet to the

destination system only

Network Hardware

• NIC– PCI or ISA– Communicates

between physical media and computer

– Driver– Works in the MAC

sub-layer of the Data Link layer

64-Bit PCI 32-Bit PCI

Network Hardware Cont.

• Bridge– Connects two network

segments together– Operates at the Data

Link layer– Filters data based on

network segment– Broadcast messages

are still sent to all connected nodes

• Router– Connects two network

segments together– Operates at the

Network Layer– Provides best route for

data– Can work with multiple

network types– Two major types:

Static and Dynamic

Network Hardware Cont.

• Gateway– Device that sits

between LAN and WAN

Network Hardware Cont.

• Wireless Access Point (WAP)– Central Point in a

wireless network

NOS

• Windows 2000– Active Directory– Domain Controller

• NT 4.0– PDC/BDC

• Unix and derivatives– NIS – SAMBA

Network Security• Outside Threats

– DOS, DDOS– Virus– Intrusion

• Internal Threats– Intentional, Unintentional

• Encryption– Data– Communication

• VPN– Uses Point to Point Tunneling Protocol

• Shares– Can be setup as read, write, execute, and delete.

Network Health

• Common Sense– Computer don’t like water and heat

• Data Redundancy– Tape Backup – RAID

• Mirroring- copying one partition to another disk.

Network Protocols

• TCP/IP– TCP (Transport Control Protocol)

• Packet ACK, Error Detection, Flow Control• Adds sequencing numbers to packets so they can be

reassembled

– IP (Internet Protocol)• 32 bit number• Routable/Non Routable

– 192.168.0.0-192.168.255.255– 172.16.0.0-172.32.255.255– 10.0.0.0-10.255.255.255

• UDP (User Datagram Protocol)– Similar to TCP but no connection is maintained

Network Protocols Cont.

• NetBEUI– Not a routable protocol– Used primarly in windows systems

• IPX/SPX– Internetwork Exchange/Sequenced Packet

Exchange