Powerpoint - Chapter 5

advertisement
Chapter Overview




Ethernet
Token Ring
FDDI
Wireless Networking
1
Ethernet Standards


Ethernet is the most popular local area
network (LAN) protocol operating at the datalink layer.
There are two sets of Ethernet standards:


DIX Ethernet
Institute of Electrical and Electronic Engineers
(IEEE) 802.3
2
DIX Ethernet Standards


DIX Ethernet. Also known as thick Ethernet,
ThickNet, or 10Base5
DIX Ethernet II. Retains 10Base5 and adds
10Base2 (thin Ethernet)
3
IEEE 802.3 Standards



IEEE 802.3. 10Base5, 10Base2, and 10Base-T
IEEE 802.3u. Fast Ethernet
IEEE 802.3z and IEEE 802.3ab. Gigabit
Ethernet
4
DIX Ethernet/IEEE 802.3
Components



Physical layer specifications
Frame format
CSMA/CD MAC mechanism
5
Standard 10-Mbps Ethernet
Specifications
Designation
Cable Type
Topology Maximum
Length
10Base5
RG-8 coaxial
Bus
500 meters
10Base2
RG-58 coaxial
Bus
185 meters
10Base-T
Category 3 UTP
Star
100 meters
Fiber Optic InterMultimode fiber
Repeater Link (FOIRL) optic
Star
1,000 meters
10Base-F
Star
500–2,000
meters
Multimode fiber
optic
6
Fast Ethernet (100 Mbps)
Specifications
Designation Cable Type
Topology Maximum
Length
100Base-TX
Category 5 UTP
Star
100 meters
100Base-T4
Category 3 UTP
Star
100 meters
100Base-FX
Multimode fiber
optic
Star
412 meters
7
Gigabit Ethernet (1,000 Mbps)
Specifications
Designation
Cable Type
Topology
Maximum Length
1000Base-T
Category 5 or 5E UTP
Star
100 meters
1000Base-LX
Various multimode fiber
optic
Star
550–5,000 meters
1000Base-SX
Various multimode fiber
optic
Star
220–500 meters
1000Base-LH
Singlemode fiber optic
Star
10 kilometers
1000Base-ZX
Singlemode fiber optic
Star
100 kilometers
1000Base-CX
150-ohm copper
Star
25 meters
8
Coaxial Ethernet Standards


10Base5 (thick Ethernet)
10Base2 (thin Ethernet)
9
Coaxial Network Characteristics



Runs at 10 Mbps
Uses the bus topology
Uses mixing segments
10
Mixing Segments
11
UTP Ethernet Standards




10Base-T
100Base-TX (Fast Ethernet)
100Base-T4 (Fast Ethernet)
1000Base-T (Gigabit Ethernet)
12
UTP Network Characteristics




Runs at various speeds up to 1,000 Mbps
Uses the star topology
Requires a hub
Uses link segments
13
Link Segments
14
Fiber Optic Ethernet


Fiber Optic Inter-Repeater Link (FOIRL)
IEEE 802.3 fiber optic standards:





10Base-FL
10Base-FB
10Base-FP
100Base-FX
Gigabit Ethernet standards
15
The 5-4-3 Rule

A standard network can have no more than
FIVE segments, connected by FOUR
repeaters, of which no more than THREE
segments can be mixing segments.
16
A Coaxial 5-4-3 Network
17
A UTP 5-4-3 Network
18
Fast Ethernet Hub Types
Class
Function
I
Connects different cable segment types
II
Connects identical cable segment types
19
Fast Ethernet Cabling Guidelines
Hub
Type
Maximum Maximum
Number
Total Cable
of Hubs
Length (UTP)
Maximum Total
Cable Length
(Fiber Optic)
Class I
1
200 meters
272 meters
Class II 2
205 meters
228 meters
20
The Ethernet Frame Format
21
Protocol Identification


DIX Ethernet frames use the Ethertype field.
IEEE 802.3 frames use the Logical Link
Control (LLC) and Subnetwork Access
Protocol (SNAP) subheaders.
22
Media Access Control (MAC)

Is the mechanism that enables multiple
computers to use the same network medium
without conflicting
23
CSMA/CD Phases
Phase
Description
Carrier sense
A computer listens to the network
before transmitting.
Multiple access
When the network is clear, the
computer transmits the packet.
Collision detection
The computer checks for signs of a
collision. If one occurs, it retransmits
the packet.
24
Collisions




Collisions are also called signal quality errors.
They are normal on Ethernet networks.
The frequency of collisions increases as
network traffic increases.
Late collisions are a sign of a serious
problem.
25
Token Ring Cable Types


IBM Type 1. Proprietary shielded twisted pair
(STP)
IBM Type 3. Standard Category 5 unshielded
twisted pair (UTP)
26
IBM Type 1 Cable
27
Token Passing



A token frame circulates continuously around
the network.
Only the computer holding the token can
transmit data.
The transmitting system is responsible for
removing the data from the ring.
28
Token Ring Frame Types




Data frame
Token frame
Command frame
Abort delimiter frame
29
The Data Frame Format
30
The Token Frame Format
31
Fiber Distributed Data Interface
(FDDI) Characteristics



First commercial 100-Mbps fiber optic
protocol
Uses the token passing MAC mechanism
Supports both singlemode and multimode
cable
32
FDDI Topologies



Double ring
Logical ring
Dual ring of trees
33
Dual Ring of Trees
34
The FDDI Data Frame
35
IEEE 802.11 Standards


IEEE 802.11a. Speeds of 1 to 2 Mbps
IEEE 802.11b. Speeds of 5.5 to 11 Mbps
36
IEEE 802.11 Topologies


Ad hoc. Wireless computers communicating
with each other
Infrastructure. Wireless computers using an
access point to communicate with a cabled
network
37
CSMA/CA


Carrier Sense Multiple Access with Collision
Avoidance (CSMA/CA) is a variation of
CSMA/CD.
It uses packet acknowledgment messages
instead of collision detection.
38
Chapter Summary

Ethernet



Token Ring



Uses a logical ring topology
Uses the token passing MAC mechanism
FDDI



Supports multiple cable types and speeds
Uses the CSMA/CD MAC mechanism to detect collisions
Uses a double ring or star topology
Uses the token passing MAC mechanism
Wireless Networking


Runs at speeds up to 11 Mbps
Uses the CSMA/CA MAC mechanism
39
Download