Foundation Summary

Study Material For Cisco Ccna Ccnp And Ccie Students

Study Material For Cisco Students

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The "Foundation Summary" section of each chapter lists the most important facts from the chapter. Although this section does not list every fact from the chapter that will be on your CCNA exam, a well-prepared CCNA candidate should know, at a minimum, all the details in each "Foundation Summary" section before going to take the exam.

Table 11-8 summarizes the type of physical topology covered in this chapter. Table 11-8 Physical Topology Types

Term

Definition

Bus

This is a linear topology, with all devices connected to the cable.

Star

Each device is connected to a central point. Sometimes called hub-and-spoke.

Extended star

A star topology is in the center, but instead of each point being a single device, it can be the center of another star topology.

Full mesh

Each device has a direction connection to each other device.

Partial mesh

Each device does not have a direct connection to each other device.

Single ring

Each device is connected connected to two others so that the signal is repeated in one direction, causing a ring or loop.

Dual ring

Two rings go through the same set of devices, allowing loops to be made upon failure, which continues the operation of a ring.

Figure 11-15 shows a conceptual diagram of UTP and STP cabling.

Figure 11-15 UTP and STP Cable Components

UTP Cable STP Cable

Twisted Pair

Each "Wire" Is Copper with Colored Plastic Insulation

Outer Part of Cable

Shielding All Pairs

Shielding per Pair

Outer Part of Cable

Shielding All Pairs

UTP Cable, End View

• Plastic Insulation Color is that

You See in an RJ-45 Connector

• Plastic Insulation Color is that

You See in an RJ-45 Connector

Table 11-9 outlines the types of UTP cabling. Table 11-9 Physical Topology Types

Category

Max Speed Rating

Description

1

Used for telephones but not for data.

2

4 Mbps

Originally intended to support Token Ring over UTP.

3

10 Mbps

Can be used for telephones as well. Popular option for Ethernet in years past, if CAT3 cabling for phones already was in place.

4

16 Mbps

Intended for the fast Token Ring speed option.

5

1 Gbps

Very popular for cabling to the desktop.

5e

1 Gbps

Lower emissions, more expensive than CAT5, but better for Gigabit Ethernet.

6

1 Gbps+

Intended as a replacement for CAT5e, with capabilities to support multigigabit speeds when standards are created.

Figure 11-16 shows the pinouts on a typical four-pair UTP cable using an RJ-45 connector. Figure 11-16 Four-Pair UTP Cable: Pinouts Using RJ-45

Figure 11-16 shows the pinouts on a typical four-pair UTP cable using an RJ-45 connector. Figure 11-16 Four-Pair UTP Cable: Pinouts Using RJ-45

Figure 11-17 shows a side view of an optical cable, including a view of the optical fiber itself.

Figure 11-17 Components of a Fiber-Optic Cable

Outer Part Kevlar Plastic of Cable Shield Shield

Side View

Figure 11-17 Components of a Fiber-Optic Cable

Outer Part Kevlar Plastic of Cable Shield Shield

Optical Fiber

Incoming Light Multi Mode —

■ Cladding Core

Optical Fiber

Core

Cladding

Table 11-10 summarizes the types of cable and main features, with some comments about disadvantages and advantages of each.

Table 11-10 Summary of Ethernet Cabling Types

Maximum Length, Single Segment

Maximum Speed for Ethernet

Relative Cost

Advantages

Disadvantages

UTP

100 m

1 Gbps

Low

Easy to install, commonly available, popular

Susceptible to interference, limited distance

STP

100 m

100 Mbps

Medium

Low emissions, less susceptible to interference

Difficult to work with, limited distance

185 m (thinnet)

100 Mbps

Medium

Least susceptible to interference of all copper media

Difficult to work with (thicknet), single cable problem fails whole network

Fiber

10 km+ (SM) 2 km+ (MM)

10 Gbps (MM)

High

More secure, long distances, not susceptible to EMI, highest speeds

Difficult to terminate when attaching connectors

Tables 11-11, 11-12, and 11-13 list the pertinent details of the standards and the cabling. Table 11-11 Ethernet 802.3 Cabling Standards

Standard

Cabling

Maximum Length

10BASE5

Thick coaxial

500 m

10BASE2

Thin coaxial

185 m

10BASE-T

UTP CAT3, 4, 5, 5e, 6

100 m

Table 11-12 FastEthernet 802.3u Cabling Standards

Standard

Cabling

Maximum Length

100BASE-FX

Two strands, multimode

400 m

100BASE-T

UTP CAT3, 4, 5, 5e, 6, two-pair

100 m

100BASE-T4

UTP CAT3, 4, 5, 5e, 6, four-pair

100 m

100BASE-TX

UTP CAT3, 4, 5, 5e, 6, or STP, two-pair

100 m

Table 11-13 Gigabit 802.3z (Optical) and 802.3ab (Electrical) Cabling Standards

Standard

Cabling

Maximum Length

1000BASE-LX

Long-wavelength laser, MM or SM fiber

10 km (SM) 3 km (MM)

1000BASE-SX

Short-wavelength laaser, MM fiber

220 m with 62.5-micron fiber; 550 m with 50-micron fiber

1000BASE-ZX

Extended wavelength, SM fiber

100 km

1000BASE-CS

STP, two-pair

25 m

1000BASE-T

UTP CAT5, 5e, 6, four-pair

100 m

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