Ccna1 M5 Cabling Lans Wans

CCNA – Semester1

Module 5 Cabling LANs and WANs

Objectives

• Identify characteristics of Ethernet networks. • Describe the function of network devices

• Describe and cabling the LANs • Decribe WAN connections and cabling the WANs

Cabling the LANs

LAN Physical Layer • Each media has advantages and disadvantages. Some of the advantage or disadvantage comparisons concern the following: – – – –

Cable length Cost Ease of installation Susceptibility to interference

Ethernet Family

Ethernet Standard • Ethernet is the most widely used LAN technology. • Ethernet was first implemented by the Digital, Intel, and Xerox group, referred to as DIX. • DIX Ethernet was used as the basis for the Institute of Electrical and Electronics Engineers (IEEE) 802.3 specification, released in 1980. • Later, the IEEE extended 802.3 to three new committees known as 802.3u (Fast Ethernet), 802.3z (Gigabit Ethernet over Fiber), and 802.3ab (Gigabit Ethernet over UTP).

Ethernet Cable and Connector

UTP Implementation • EIA/TIA specifies an RJ45 connector for unshielded twisted-pair (UTP) cable. The letters RJ stand for registered jack, and the number 45 refers to a specific wiring sequence.

Attach the RJ-45

RJ-45 Jack RJ-45 Plug

Repeater: Layer 1 • Repeater regenerate and retime network signals at the bit level to allow them to travel a longer distance on the media.

4 repeater rule 5.4.3.2.1 Rule • • • • •

• •

5 sections of the network. 4 repeaters or hubs. 3 sections for hosts. 2 sections for link purposes. 1 large collision domain.

This rule states that no more than four repeaters can be used between hosts on a LAN. This rule is used to limit latency added to frame travel by each repeater. Too much latency on the LAN increases the number of late collisions and makes the LAN less efficient.

Hubs: Layer 1 • Multiport repeater • The physical topology for using a hub star. • Sometimes called concentrator • There are 3 types of hub: active, passive and intelligent • Every device connected to the same network segment is said to be a member of a collision domain.

Network Segmentation •

When the number of network node is big, reducing network performance, it is necessary to break up a large LAN into smaller, more easily managed segments.

Bridge Functions • Switches and bridges operate at the Data Link layer of the OSI model. • The function of the bridge is to make intelligent decisions about whether or not to pass signals on to the next segment of a network.

Bridge Functions • The function of the bridge is to make intelligent decisions about whether or not to pass signals on to the next segment of a network. • They makes these decisions based upon the layer 2 physical address (MAC). • A switch therefore has two main functions: – switch data frames – build and maintain tables

LAN Switch • Switches operate at much higher speeds than bridges and can support new functionality, such as virtual LANs. • Switches can easily replace hubs

Cisco Catalyst

Catalyst 2950

Catalyst 6500 Catalyst 3550

Switch: Micro-segmentation •

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An Ethernet switch allows many users to communicate in parallel in a virtually collisionfree environment. Ethernet switches have such benefits: – reduces network congestion – maximizes bandwidth – reduces collision domain size

Host Connectivity - NIC • The NIC is also referred to as a network adapter and is considered Layer 2 devices because each NIC carries a unique code called a MAC address. • When selecting a NIC, consider the following: – – – – –

Network architecture Operating system Media type Data transfer speed Available bus types

Type of network

Peer-to-peer versus Client/Server

Cabling the WANs

WAN physical layer

• The physical layer implementations vary depending on: – distance of the equipment from the services – speed – type of service itself

WAN Serial Connections

• If the connection is made directly to a service provider, or a device that provides signal clocking such as a channel/data service unit (CSU/DSU), the router will be a data terminal equipment (DTE) and use a DTE serial cable.

Routers and Serial Connections

• Determine whether DTE or DCE connectors are required. The DTE is the endpoint of the user’s device on the WAN link. • The DCE is the point where responsibility for delivering data passes into the hands of the service provider.

Fixed and modular port • Interfaces on routers with fixed serial ports are labeled for port type and port number (eg S1). Ethernet AUI port need transceiver to convert from DB-15 to RJ45 • Interfaces on routers with modular serial ports are labeled for port type, slot, and port number (eg: S0/1).

Routers and DSL Connections • •

The Cisco 827 ADSL router has one Asymmetric Digital Subscriber Line (ADSL) interface. To connect an ADSL line to the ADSL port on a router, do the following: – –

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Connect the phone cable to the ADSL port on the router. Connect the other end of the phone cable to the phone jack.

DSL works over standard telephone lines using pins 3 and 4 on a standard RJ-11 connector.

Routers and Cable Connections • The Cisco uBR905 cable access router provides highspeed network access on the cable television system to residential and small office, home office (SOHO) subscribers.

Setting Up Console Connections •

The console port allows monitoring and configuration of a Cisco hub, switch, or router. The AUX port allows remote monitoring and configuration of devices over modem connection. To set up a connection between the terminal and the Cisco console port, perform two steps.

• • – –

Connect the devices using a rollover cable from the console port, on the router, to the serial port, on the terminal (workstation). Configure the terminal emulation application with the following common equipment (COM) port settings: 9600 bps, 8 data bits, no parity, 1 stop bit, and no flow control.

Lab Companion • • • • •

5.1.5 RJ-45 Jack Punch Down 5.1.12 Building a Peer-to-Peer Network 5.1.13 Building a LAN Network 5.2.3 Interconnecting network devices 5.2.7 Establishing a Console Connection to a Router or Switch

Summary • • • • • • • •

LAN physical layer Ethernet standards 5-4-3 rule Functions of network devices Peer-to-peer versus client/server network WAN physical layer WAN connections WAN technologies