ethernet hardware cabling –twisted pair 100 meter length limit point to point –fiber expense...
Post on 21-Dec-2015
218 views
TRANSCRIPT
Ethernet Hardware
• Cabling– Twisted Pair
• 100 Meter length limit
• Point to Point
– Fiber• Expense
• Point to Point
• 2000 meter length limit
Ethernet Cabling Cont.
– Coax (10 MB ethernet only)• inexpensive
• Bus System (party line)
• Thin (185 Meter length limit)– 30 connections/cable, min 18 inches between
• Thick (500 meter length limit)– 200 connections, min 2.5M between
• Transceivers
10baseT/100baseT
• 2 twisted pairs
• Transmit/Receive
• 100 meter/328 foot distance limit
• Uses standard telephone modular plugs
• Category 3 (10mb) vs. Category 5 (100mb)
1
2
3
4
5
7
8
6
White/Orange
Orange/White
White/Green
Green/White
Blue/WhiteWhite/Blue
White/Brown
Brown/White
Hubs and Repeaters
• Hubs (Star topology)
Twisted Pair
Fiber, Coax, Twisted Pair
Backbone
(Twisted Pair may needa twist!)
Hub Advantages
• Standard Telephone Wiring
• Standard Punch Blocks and Cross Connects
• Ability to disable a single port
• Easier to monitor traffic patterns
• Visible Indication of Link Status
• If a wire is cut only one port is affected – Unless the backbone feed is cut!
Coaxial Installation
• Multidrop (Bus topology)
T
T=terminator(50 ohm resistor)
Repeater
Backbone
Other computersTTT
Repeater Rule 10MB
• 3 repeater rule
Repeater
Repeater
Repeater
Repeater
System 1
Sys 2 Sys3
System 1 can talk to Sys 2 but not Sys3
100baseT to 10baseTHub/Bridge10baseT 100baseT
10baseT hub
100baseT hub
100baseTto10baseTBridgeModule
Ethernet Rules
• 3 repeater (populated) limit
• 5 repeater per segment limit
• 7 bridges
• Cable lengths
• Number of stations/cable
How to get around limits?Hubs
Switch
ROUTER
Other Lans
To the Internet(switchingbased onIP address)
Firew
all
Ethernet Errors
• Carrier Loss• Collisions
– How many are tolerable?
• Jabber• Runts
– Causes
• Tools– tcpdump, snoop, traceroute, ping
Appletalk
• EtherTalk– uses ethernet
• LocalTalk– Serial link at 230KB/s
• TokenTalk• AppleShare
– File Sharing
• Zones
Routers
• Advantages– Multi Protocol– Broadcast filtering
• Disadvantages– Cost– Complexity
• Configuration
Complex System
Modems
AT
M S
witch
FD
DI
Concentrator
A
B
C
D
Buildings
Router
Router
Primaryrouter
To Internet
Routed vs. Switched Network
• Routed– IP/IPX Layer Routing
– Subnetted Network
– Broadcast Filtering
– More Expensive
– Complex Configuration
– Better Control
• Switched– Ethernet Layer Routing
– Flat Network
– Broadcasts progagate
– Less Expensive
– Simple Configuration
– Loose Control
– Network Diameter limit