CABLING LANs & WANs Module 5 Semester I

Content Cabling the LAN Cabling the WAN

Objectives Identify straight-through, crossover, and rollover cables. Identify characteristics of Ethernet networks. Identify straight-through, crossover, and rollover cables. Describe the function, advantages, and disadvantages of repeaters, hubs, bridges, switches, and wireless network components. Describe the function of peer-to-peer networks. Describe the function, advantages, and disadvantages of client-server networks. Describe and differentiate between serial, Integrated Services Digital Network (ISDN), digital subscriber line (DSL), and cable modem WAN connections. Identify router serial ports, cables, and connectors. Identify and describe the placement of equipment used in various WAN configurations.

Cabling the LAN The Physical Layer

Networking Media Carry flow of information Media Types Coaxial Fiber Optic Space Category 5 unshielded twisted-pair cable (Cat 5 UTP) Media Characteristics: Cable length Cost Ease of installation Susceptibility to interference A subset of physical layer implementations for Ethernet LANs

Ethernet Media Ethernet technologies can be used in a campus network in several different ways: 10 Mbps at the user level to provide good performance. 100 Mbps for clients or servers that require more bandwidth. Fast or Gigabit Ethernet between backbone devices.

Media Connectors

RJ-45 connectors This is the Connector This is the Jack

568B pin assignments – straight cable Transmit Data Tip +ve Transmit Data Ring -ve Receive Data Ring -ve Receive Data Tip +ve

Cross Over cable – pin assignments

Interconnecting Devices Use straight-through cables for… Switch to router Switch to PC or server Hub to PC or server Use roll-over cables to… Connect a terminal to a console port Use crossover cables for… Switch to switch Switch to hub Hub to hub Router to router PC to PC Router to PC

LAN Devices Repeaters, Hubs, Bridges, Switches

Hubs Repeaters - Hubs Repeaters A repeater regenerates and retimes network signals at the bit level to allow them to travel a longer distance 5-4-3 Rule for 10-Mbps Ethernet should be used to limit latency Too much latency on the LAN increases the number of latecollisions and makes the LAN less efficient Hubs Hubs are actually multiport repeaters Change the network topology from a linear bus to a star Three basic types: Passive – no boost, no clean and no power Active - needs power to amplify the incoming signal Intelligent - microprocessor chip and diagnostic capabilities

Bridges & Switches Bridges Switches Bridges and switches operate at the Data Link layer. Destination MAC address is looked up in the bridge table to determine whether to filter, flood, or copy the frame onto another segment. Switches A switch has many ports with many network segments connected to them. A switch chooses the port to which the destination device is connected. Alleviates congestion in LANs by reducing the size of collision domains, reducing traffic and increasing bandwidth. Two basic operations: Switching data frames. Build and maintain switching tables and search for loops. Switches operate at much higher speeds than bridges and can support new functionality, such as virtual LANs.

Wireless IR weaknesses: Much less cabling RF, IR, laser, satellite, microwaves The only cabling can be to the Access Points The transmitter converts source data to EM waves The receiver converts waves back into data All devices in WLAN must have Wireless NICs IR weaknesses: ‘Line of sight’ limitation (newer technologies combat this) Signal weakening or obstruction by people or humidity RF technology works between rooms or even buildings RF weaknesses: Single frequency is subject to outside interference and obstructions Single frequency is easily monitored by others making it insecure FHSS and DSSS are Spread Spectrum technologies which add security and immunity to noise by using multiple frequencies

NIC The function of a NIC is to connect a host device to the network medium The NIC is also referred to as a network adapter NICs are considered Layer 2 devices because each NIC carries a unique code called a MAC address

Network Environments

Peer-to-Peer In a peer-to-peer network networked computers act as equal partners, or peers individual users control their own resources Peer-to-peer networks are relatively easy to install and operate A peer-to-peer network works well with 10 or fewer computers peer-to-peer networks do not scale well, their efficiency decreases rapidly as the number of computers on the network increases Security is difficult to maintain

Client/Server In a client/server arrangement, network services are located on a dedicated computer called a server The server is a central computer that is continuously available to respond to requests from clients for file, print, and application services Servers are designed to handle requests from many clients simultaneously The aggregation of resources on server systems brings greater security, simpler access and coordinated control, the server introduces a single point of failure

Peer-to-Peer vs. Client/Server Advantages Advantages of a Peer-to-Peer Network Advantages of a Client/Server Network Less expensive to implement Provides for better security Does not require additional specialized network administration software Easier to administer when the network is large due to centralized administration Does not require a dedicated network administrator All data can be backed up on one central location

Peer-to-Peer vs. Client/Server Disadvantages Disadvantages of a Peer-to-Peer Network Disadvantages of a Client/Server Network Does not scale well to a large networks and administration becomes unmanageable Requires expensive specialized network administrative and operational software Each user must be trained to perform administrative tasks Requires expensive, more powerful hardware for the server machine Less secure Requires a professional administrator All machines sharing resources negatively impacts performance Has a single point of failure. User data is unavailable if the server is down

WAN Connections Serial connections are used to support WAN services such as dedicated leased lines that run Point-to-Point Protocol (PPP) or Frame Relay

WAN WANs use serial transmission This is a process by which bits of data are sent over a single channel This process provides reliable long distance communication and the use of a specific electromagnetic or optical frequency range Signals transmitted over voice grade telephone lines use 3 kilohertz (kHz).

WAN Serial connections are used to support WAN services such as dedicated leased lines that run Point-to-Point Protocol (PPP) or Frame Relay ISDN offers dial-on-demand connections or dial backup services. ISDN Basic Rate Interface (BRI) is composed of: Two 64 kbps bearer channels (B channels) for data One delta channel (D channel) at 16 kbps used for signaling and other link-management tasks PPP is typically used to carry data over the B channels.

Router Connections Cisco router physical connectivity is provided by serial connections: The first type of serial connections is a 60-pin connector The second is a more compact ‘smart serial’ connector The provider connector will vary depending on the type of service equipment

DTE/DCE When 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. When the local router is required to provide the clocking rate it will use a data communications equipment (DCE) cable

Router Connection Points

Managing Routers To initially configure the Cisco device, a management connection must be directly connected to the device The console port allows monitoring and configuration of a Cisco hub, switch, or router The cable used between a terminal and a console port is a rollover cable also known as a console cable

Console Connection

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LABS

LABS 5.1.5 RJ-45 jack punch down 5.1.7 Hub & NIC purchase 5.1.10 Purchasing LAN Switches 5.1.12 Building a Peer to Peer network 5.1.13a Building a HUB based network 5.1.13b Building a Switch based network