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TC 361 Data Networking
Test 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