Wireless
A wireless network consists of wireless NICs and
access points. NICs come in different models including PC Card, ISA, PCI, etc.
Access points act as wireless hubs to link multiple wireless NICs into a single
subnet. Access points also have at least one fixed Ethernet port to allow the
wireless network to be bridged to a traditional wired Ethernet network, such as
the organization’s network infrastructure. Wireless and wired devices can
coexist on the same network.
1.2
Specify the main features of 802.2 (Logical Link Control), 802.3 (Ethernet),
802.5 (token ring), 802.11 (wireless), and FDDI (Fiber Distributed Data
Interface) networking technologies, including:
> 802.3 (Ethernet) Carrier Sense Multiple Access
with Collision Detection (CSMA/CD) LAN Ethernet
Access
method
· CSMA/CA (Carrier Sense Multiple Access/Collision
Avoidance)
· CSMA/CD (Carrier Sense Multiple Access /
Collision Detection)
A type of media access control. With CSMA/CD, a
computer listens to the network to determine whether another computer is
transmitting a data frame. If no other computer is transmitting, the computer
can then send its data. While the computer is listening for a data signal, that
would be the carrier sense part. Multiple access means, there are multiple
computers trying to access or send data on the network at the same time.
Collision detection indicates that the computers are also listening for
collisions, if two computers try to send data at the same time and a collision
occurs, they must wait a random period of time before transmitting again.
|
Designation
|
Supported Media
|
Maximum Segment Length
|
Transfer Speed
|
Topology
|
|
10Base-5
|
Coaxial
|
500m
|
10Mbps
|
Bus
|
|
10Base-2
|
ThinCoaxial
(RG-58 A/U)
|
185m
|
10Mbps
|
Bus
|
|
10Base-T
|
Category3
or above unshielded twisted-pair (UTP)
|
100m
|
10Mbps
|
Star,using
either simple repeater hubs or Ethernet switches
|
|
1Base-5
|
Category3
UTP, or above
|
100m
|
1Mbps
|
Star,using
simple repeater hubs
|
|
10Broad-36
|
Coaxial(RG-58
A/U CATV type)
|
3600m
|
10Mbps
|
Bus(often
only point-to-point)
|
|
10Base-FL
|
Fiber-optic-
two strands of multimode 62.5/125 fiber
|
2000m
(full-duplex)
|
10Mbps
|
Star(often
only point-to-point)
|
|
100Base-TX
|
Category5
UTP
|
100m
|
100Mbps
|
Star,using
either simple repeater hubs or Ethernet switches
|
|
100Base-FX
|
Fiber-optic-
two strands of multimode 62.5/125 fiber
|
412
meters (Half-Duplex)
2000 m
(full-duplex)
|
100
Mbps
(200
Mb/s full-duplex mode)
|
Star(often
only point-to-point)
|
|
1000Base-SX
|
Fiber-optic-
two strands of multimode 62.5/125 fiber
|
260m
|
1Gbps
|
Star,using
buffered distributor hub (or point-to-point)
|
|
1000Base-LX
|
Fiber-optic-
two strands of multimode 62.5/125 fiber or monomode fiber
|
440m
(multimode) 5000 m (singlemode)
|
1Gbps
|
Star,using
buffered distributor hub (or point-to-point)
|
|
1000Base-CX
|
Twinax,150-Ohm-balanced,
shielded, specialty cable
|
25m
|
1Gbps
|
Star(or
point-to-point)
|
|
1000Base-T
|
Category5
|
100m
|
1Gbps
|
Star
|
> 802.5 (token ring)
The IEEE 802.5 Token Ring standards define
services for the OSI physical layer and the MAC sublayer of the data link
layer. Token Ring computers are situated on a continuous network loop. A Token
Ring controls access to the network by passing a token, from one computer to
the next. Before they can transmit data they must wait for a free token, thus
token passing does not allow two or more computers to begin transmitting at the
same time.
|
Media
|
MAC Method
|
Signal Propagation Method
|
Speed
|
Topologies
|
Maximum Connections
|
|
Twisted-pair(various
types)
|
Tokenpassing
|
Forwardedfrom
device to device (or port to port on a hub) in a closed loop
|
4Mbps
16 Mbps |
Ring
Star-using Token Ring repeater hubs |
255nodes
per segment
|
> 802.11b (wireless)
802.11b is a
wireless Ethernet technology operating at 11MB. 802.11b devices use Direct
Sequence Spread Spectrum (DSSS) radio technology operating in the 2.4GHz
frequency band.
An 802.11b
wireless network consists of wireless NICs and access points. Access points act
as wireless hubs to link multiple wireless NICs into a single subnet. Access
points also have at least one fixed Ethernet port to allow the wireless network
to be bridged to a traditional wired Ethernet network.. Wireless and wired
devices can coexist on the same network.
802.11b devices
can communicate across a maximum range of 50-300 feet from each other.
> FDDI networking technologies
Fiber
Distributed Data Interface, shares many of the same features as token ring,
such as a token passing, and the continuous network loop configuration. But
FDDI has better fault tolerance because of its use of a dual, counter-rotating
ring that enables the ring to reconfigure itself in case of a link failure.
FDDI also has higher transfer speeds, 100 Mbps for FDDI, compared to 4 - 16
Mbps for Token Ring.
Unlike Token Ring, which uses a star topology,
FDDI uses a physical ring. Each device in the ring attaches to the adjacent
device using a two stranded fiber optic cable. Data travels in one direction on
the outer strand and in the other direction on the inner strand. When all
devices attached to the dual ring are functioning properly, data travels on
only one ring. FDDI transmits data on the second ring only in the event of a
link failure.
|
Media
|
MAC Method
|
Signal Propagation Method
|
Speed
|
Topologies
|
Maximum Connections
|
|
Fiber-optic
|
Token
passing
|
Forwardedfrom
device to device (or port to port on a hub) in a closed loop
|
100
Mbps
|
Double
ringStar
|
500
nodes
|
1.3
Specify the characteristics (For example: speed,length, topology, and cable
type) of the following cable standards:
|
|
Cable Type
|
Maximum Length
|
Max. Speed
|
Topology
|
|
10Base-T
|
Category
3 or above unshielded twisted-pair (UTP)
|
100 m
|
10 Mbps
|
Star,
using either simple repeater hubs or Ethernet
switches |
|
10BASE-FL
|
Fiber-optic
|
Segment
may be up to 2,000 meters in length if only 10BASE-FL
equipment is used on the segment. |
|
Fiber
optic link segments a star topology
|
|
100Base-TX
|
Category
5 UTP
|
100 m
|
100
Mbps
|
Star,
using either simple repeater hubs or Ethernet switches
|
|
100Base-FX
|
Fiber-optic
|
412
meters (Half-Duplex)
2000 m
(full-duplex)
|
100
Mbps
(200
Mb/s full-duplex mode)
|
Star
(often only point-to-point)
|
|
1000Base-LX
|
Fiber-optic
|
440 m
(multimode) 5000 m (singlemode)
|
1 Gbps
|
Star,
using buffered distributor hub (or point-to-point)
|
|
1000Base-T
|
Category
5
|
100 m
|
1 Gbps
|
Star
|
|
100BASE-TX
|
|
|
|
|
|
1000BASE-CX
|
Copper
cable (balanced shielded twisted pair).
|
maximum
of 25m per segment
|
1 Gbps
|
Obsolete
standard for 1GB Ethernet over short distances. Succeeded
by 1000BASE-T |
|
10GBASE-T
|
unshielded
twisted pair cables Category 5e or Category 6 or Category
7 cables. Augmented Category 6 cable is being developed which will to reduce crosstalk between the cables |
100m
|
A standard proposed
by the IEEE 802 committee to provide 10 Gigabit/second |
Proposal
for 10GBASE-T calls will use the conventional RJ-45 used for ethernet
LANs.
IEEE P802.3an (10GBASE-T)
Task Force |
|
10
GBASE-SR
|
multimode
fiber
Two
strands of 62.5/125 (30m)or 50/125 (300m) micron core fiber cable
|
From
30m up to 300 meters depending on the type and quality of
the multimode fiber. |
10 Gbps
|
|
|
10
GBASE-LR
|
single-mode
fiber
|
10
kilometers
|
10 Gbps
|
|
|
10
GBASE-ER
|
Fiber
optic cable
|
40
kilometers
|
10 Gbps
|
|
