Chapter 8Chapter 8Help is here!Help is here!

CablingCablingWhenever you need cabling that will Whenever you need cabling that will protect your signal from electrical protect your signal from electrical interference there is only one correct interference there is only one correct answer:answer:

Fiber OpticFiber OpticIt’s Fragile – Often protected by several It’s Fragile – Often protected by several layers.layers.

TopologiesTopologiesMesh has a high level of redundancy. Mesh has a high level of redundancy.

Every device is connected to every other Every device is connected to every other devicedevice

It takes a licking and keeps on ticking.It takes a licking and keeps on ticking.Even if a cable fails communication Even if a cable fails communication continues.continues.

This is used in most WAN’s. It’s how the This is used in most WAN’s. It’s how the internet continues to work even if there is internet continues to work even if there is a cable failure.a cable failure.

Why Client-Why Client-Server?Server?

There are many advantages to a client-There are many advantages to a client-server model. Among them:server model. Among them:

Better securityBetter security

Centralized data storage for easier file Centralized data storage for easier file sharing.sharing.

Centralized data can easily be backed up.Centralized data can easily be backed up.

Also makes it easy to administer Also makes it easy to administer permissions and groups of users.permissions and groups of users.

Switches vs. HubsSwitches vs. HubsSwitches segment the network, reducing Switches segment the network, reducing traffic.traffic.

Hubs extend Broadcast/Collision Domains. Hubs extend Broadcast/Collision Domains. They do not segment the network.They do not segment the network.

Hubs are dumb devices. They send Hubs are dumb devices. They send packets to all ports other than the one the packets to all ports other than the one the packet came in on.packet came in on.

Switches maintain lists matching Mac Switches maintain lists matching Mac Addresses with ports. Packets in switches Addresses with ports. Packets in switches are routed only a specific destination port.are routed only a specific destination port.

DHCPDHCPAutomatically configures network Automatically configures network devices.devices.

UTP CablingUTP CablingNumber of twists and number of Number of twists and number of conductors is what determines the conductors is what determines the category.category.

No matter the speed all UTP cabling has No matter the speed all UTP cabling has a distance limit of 100 meters. (100 a distance limit of 100 meters. (100 Meter Rule)Meter Rule)

EthernetEthernetDefined and supported by IEEE 802.3 Defined and supported by IEEE 802.3 standards.standards.

Logical bus topologyLogical bus topology

Physical topology is a Star or Extended Physical topology is a Star or Extended Star/Hierarchical.Star/Hierarchical.

Used in most modern LANsUsed in most modern LANs

Uses CSMA/CD technology to avoid Uses CSMA/CD technology to avoid collisions. collisions.

Listen before transmit. Backs off if a Listen before transmit. Backs off if a collision occurs.collision occurs.

EncapsulationEncapsulationThe process of breaking data into The process of breaking data into segments and adding headers and segments and adding headers and trailers as it travels through the OSI trailers as it travels through the OSI model.model.

Network Network AddressingAddressing

Two types:Two types:Logical – IP AddressesLogical – IP Addresses

Assigned through DHCP (Dynamic) or by an Assigned through DHCP (Dynamic) or by an administrator (Static)administrator (Static)

Exists on the Network layer of the OSI Exists on the Network layer of the OSI model.model.

Physical Address-Mac AddressPhysical Address-Mac AddressBurned into the NIC card.Burned into the NIC card.

Exists on the Data Link Layer of the OSI Exists on the Data Link Layer of the OSI Model.Model.

PSTNPSTNPPublic ublic SSwitched witched TTelephone elephone NNetworketwork

PSTN is dial up service. It’s very slow.PSTN is dial up service. It’s very slow.

Network Network TroubleshootingTroubleshootingPingPing

Checks end-to-end connectivity.Checks end-to-end connectivity.It don’t mean a thing if you ain’t got that It don’t mean a thing if you ain’t got that ping!ping!

TracertTracertReports on the path a packet took.Reports on the path a packet took.

ISDNISDNSeldom used anymore, but still around.Seldom used anymore, but still around.

Uses 2 phone lines together.Uses 2 phone lines together.2 Data channels. One Control Channel.2 Data channels. One Control Channel.