Page 1 - © Richard L. Goldman Networking Topology ©Richard L. Goldman January 8, 2002

Page 1 - © Richard L. Goldman

NetworkingTopology

©Richard L. Goldman

January 8, 2002


Layer 1 DevicesThe Physical Layer

• Layer 1 Devices (Physical Layer)– Cables and other transmission media– NIC– Transceivers– Repeaters– Hub– MAU


Layer 1 Devices (Physical Layer)NICs and Cat. 5 Crossover Cable

Each computer needs a NIC, Network Interface Card, to physically join a network.

This example shows two computers connected with a Cat. 5 crossover cable.


Layer 1 Devices (Physical Layer) NICs and Thinnet

This example shows two computers connected with a Thinnet, coaxial cable.

Terminators are added to complete the circuit.


Layer 1 Devices (Physical Layer) NICs, Thicknet, and Transceivers

This example shows two computers connected with a Thicknet coaxial cable.

Vampire Clamp

Transceiver Drop Cable

AUI connector – Attachment Unit Interface


OSI Model

Softw

are

7 - Application

6 - Presentation

5- Session

4 - Transport

3 - Network

2 – Data Link

1 - Physical

Computer Program

Layer 1 Devices (Physical Layer) OSI Software Layers passing Data through the Hardware

OSI Model

Softw

are

7 - Application

6 - Presentation

5- Session

4 - Transport

3 - Network

2 – Data Link

1 - Physical

Computer Program

Data is passed from the User Application down through each layer of the OSI model until reaches the hardware.

It is then transmitted to the other computer.

Then back up to the receiving User Application.


Layer 1 Devices (Physical Layer) Repeater If the distances between the

computers exceed the maximum specified length, a repeater may be used to extend the length of the run.


Layer 1 Devices (Physical Layer) Hub

Hubs forward data from one computer to all other computer connected to the hub (broadcast). Hubs function as a multiport repeater by amplifying the signal which can also extends the maximum distance between computes.


Layer 1 Devices (Physical Layer) MAU – Multistation Access Unit

MAU forwards data from one computer to another in a ring until it reaches the computer it is addressed to. MAUs are used to connect computers in a Token Ring network.


Layer 2 DevicesThe Data Link Layer

• Switches are capable of directing network traffic only to the computer it is addressed to.– Also Known As

• Switching Hubs

• Layer 1 Switches

• Bridges are used to pass traffic from one subnet to another while restricting local traffic to its own subnet.


Layer 2 Devices (Data Link Layer) Switch

OSI Model

Softw

are

7 - Application

6 - Presentation

5- Session

4 - Transport

3 - Network

2 – Data Link

1 - Physical

A switch uses a MAC Address Table to route traffic to its proper destination. The MAC address table is maintained in the MAC sublayer of the Data Link Layer.


Application Interface with network services applications

Gateways

Presentation Converts data for transmission

Session Establishes, maintains, & coordinates communication

Transport Flow Control

Sequencing

Network Routing Routers

Brouters

Layer 3 Switch

Data Link Creates data frames – divides data into small pieces

Adds Destination & source addresses

Adds control code & error check code

Bridges

Switches

•Layer 2 Switch

•Switching Hub

Physical Hardware that sends and receives electrical signals on the network

Repeaters

Hubs and MAUs

Cables, Connector, NIC, etc.


Common Network Devices• Layer 5-7 (Application, Presentation, & Session Layers)

– Gateway

• Layer 3 Devices (Network Layer)– Router– Brouter– Layer 3 Switch

• Layer 2 Devices (Data Link Layer)– Switch (AKA, Switching Hub, or Layer 2 Switch)– Bridge

• Layer 1 Devices (Physical Layer)– Cables and other network media– NIC– Transceivers– Repeaters– Hub– MAU


Ethernet Topology Standards

Standard Name Cable Speed Distance IEEE Spec

10BaseT Ethernet UTP/STP 10Mbs 100m 802.3

10Base2 Thinnet Coax 10Mbs 185m 802.3

10Base5 Thicknet Coax 10Mbs 500m 802.3

10BaseF Ethernet over Fiber

Fiber 10Mbs 500m – 2000m

100BaseTX Fast Ethernet UTP/STP-Cat 5

(uses 2 pair)

100Mbs

(Full Duplex)

100m 802.3u

100BaseT4 Fast Ethernet UTP/STP-Cat 3

(uses 4 pair)

100Mbs

(Half Duplex)

100m 802.3

100BaseFX Fast Ethernet over Fiber

Fiber 100Mbs 2000m

100BaseVG “Any LAN”

(Voice Grade)

UTP/STP-Cat 3 UTP/STP-Cat 5

100Mbs 100Mbs

100m

213m

802.12

1000BaseX Gigabit

Ethernet

UTP/STP-Cat 5

or Fiber

1000Mb/s 802.3z


Terminating a Cat-5 Cablewith RJ-45 Connector


568-A

• A Category 5 cable may be terminated with RJ-45 connectors using either 568-A or 568-B wiring standards.

• Either standard works equally well.• A standard cable will have the same type of

wiring at each end of the cable.• A crossover cable will have 568-A at one

end and 568-B at the other end.


Making a 568-B Patch Cable

• When making a patch cable (a cable that will be handled) use stranded wire cable and RJ-45 connectors designed for stranded wire.

• When installing permanent cabling you may use solid wire cable with RJ-45 connectors designed for solid wire.

• Use plenum rated cable or metal conduit per code.


Strip cable jacket back about ¾ of an inch.

Pair #

1 - Blue

2 - Orange

3 - Green

4 - Brown


Arrange wires in 568-B order.

Orange StripeOrange SolidGreen StripeBlue SolidBlue StripeGreen SolidBrown StripeBrown Solid


Pin #

12345678

Trim wires squarely at ½ inch.

Align connector with cable.½ in.


Insert cable into connector.Check to make sure all wires are flush and

in proper order

Check to make sure jacket is fully inserted and is in position to be gripped by the cable retainer.

Cable Retainer


568-A WiringRJ-45 Connector


568-A WiringRJ-45 Connector


Crossover Cable

568-B

568-A

A crossover cable is made by configuring one end of a cable as 568-A and the other end of the cable as 568-B.

Green StripeGreen SolidOrange StripeBlue SolidBlue StripeOrange SolidBrown StripeBrown Solid

Orange StripeOrange SolidGreen StripeBlue SolidBlue StripeGreen SolidBrown StripeBrown Solid

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Page 1 - © Richard L. Goldman Networking Topology ©Richard L. Goldman January 8, 2002