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Ch 10 - Chapter 10 Planning and Cabling Networks

Objectives Identify the basic network media required to make a LAN connection Identify the types of connectors for intermediate and end device connections in a LAN Identify the pinout configurations for straight-through and crossover cables Identify the different cabling types, standards and ports used for WAN connections Define the role of device management connections Design an addressing scheme for an internetwork and assign range for hosts, network devices and router interface Compare and contrast the importance of network design Ch 10 -

Routers Primary devices used to interconnect networks each port on a router connects to a different network and routes packets between networks Ch 10 - Have the ability to break up broadcast domains (BD) and collision domains (CD) Used to interconnect networks that use different technologies LAN and WAN interfaces hub switch router router switch

Hubs A hub receives a signal, regenerates it, and sends the signal over all ports ports use a shared bandwidth approach reduces the LAN performance due to collisions and recovery maintains a single collision domain Ch 10 - Used in a small LAN that requires low throughput requirements or when finances are limited Less expensive than a switch

Switches A switch receives a frame and regenerates each bit of the frame on to the appropriate destination port Used to segment a network into multiple collision domains Ch 10 - Each port on the switch creates a separate collision domain creates a point-to-point logical topology to the device on each port provides dedicated bandwidth on each port Can be used to interconnect network segments of different speeds

Device Selection Factors Cost Speed and types of ports/interfaces Expandability Manageability Additional features and services Ch 10 -

Factors to Consider in Choosing a Switch Cost its capacity and features network management capabilities, embedded security technologies and optional advanced switching technologies Simple “cost per port” calculation deploy one large switch at a central location Ch 10 - cost savings may be offset by the expense from the longer cables Compare the cost of deploying a number of smaller switches connected by a few long cables to a central switch

Factors to Consider in Choosing a Switch (cont’d) Investing in redundancy a secondary switch to operate concurrently with the primary central switch additional cabling to allow the physical network to continue its operation even if one device fails Ch 10 -

Speed and Type of Ports (Interfaces) Purchasing decisions just enough ports for today’s needs mixture of UTP speeds both UTP and fiber ports Ch 10 -

Factors to Consider in Choosing a Router Expandability modular devices have expansion slots that provide the flexibility to add new modules as requirement evolve basic number of fixed ports as well as expansion slots Media additional modules for fiber optics can increase the cost Operating system features different versions of the operating system support certain features and services security, quality of service, voice over IP, routing multiple Layer 3 protocols, NAT and DHCP Ch 10 -

LAN Cabling Areas Work area Telecommunication room, also known as distribution facility Backbone cabling, also known as vertical cabling Distribution cabling, also known as horizontal cabling Ch 10 -

LAN Cabling Areas (cont’d) Cable length ANSI/TIA/EIA-568-B standard for UTP installations maximum distance of 100 meters per channel up to 5 meters of patch cable for interconnecting patch panels up to 5 meters of patch cable from the cable termination point on the wall to the computer and telephone Work area end user devices are located minimum of two jacks patch cables, which are straight-through UTP cables, are used to connect end user devices to the wall jacks EIA/TIA standard specifies the UTP patch cords to connect devices to the wall jacks have a maximum length of 10 meters a crossover cable is used to connect a switch or hub to the wall jack Ch 10 -

LAN Cabling Areas (cont’d) Telecommunications room contains the intermediary devices – hubs, switches, routers and data service units (DSUs) where connections to intermediary devices take place these devices provide the transitions between the vertical (or backbone) cabling and the horizontal cabling patch cords are used to connect patch panels and intermediary devices servers are also housed in the telecommunication room Horizontal cabling refers to cables connecting the telecommunication rooms(Server Room) with the work areas maximum cable length from a termination point in the telecommunication room to the termination at the work area outlet must not exceed 90 meters Ch 10 -

LAN Cabling Areas (cont’d) Vertical cabling refers to the cabling used to connect the telecommunication rooms to the equipment rooms( Cabling that runs between floors ) also interconnects multiple telecommunication rooms throughout the facility used for aggregated traffic, such as traffic to and from the Internet access to corporate resources at a remote location typically require high bandwidth media such as fiber-optic cabling Ch 10 -

Types of Media UTP (Category 5, 5e, 6 and 7) Fiber optics Wireless Ch 10 -

Choosing a Media Cable length does the cable need to span across a room or from a building to a building? Cost does the budget allow for using a more expensive media type? Bandwidth does the technology used with the media provide adequate bandwidth? Ease of installation does the implementation team have the ability to install the cable or is vendor required? Susceptible to EMI/RFI is the local environment going to interfere with the signal? Ch 10 -

Cable Length Total length of cable all cables from the end devices in the work area to the intermediary device, usually a switch, in the telecommunication room cable from the devices to the wall plug, through the building from the wall plug to the cross-connect (or patch panel) and from the patch panel to the switch Ch 10 - Signal attenuation and exposure to possible interference increase with cable length the horizontal cabling length for UTP needs to stay within the recommended maximum distance of 90 meters

Ethernet Cabling Standards Ch 10 - Ethernet Type Bandwidth Cable Type Maximum Distance 10Base-T 10Mbps Cat 3/Cat 5 UTP 100m 100Base-TX 100Mbps Cat 5 UTP 100m 100Base-TX 200Mbps Cat 5 UTP 100m 100Base-FX 100Mbps Multi-mode fiber 400m 100Base-FX 200Mbps Multi-mode fiber 2Km 1000Base-T 1Gbps Cat 5e UTP 100m 1000Base-TX 1Gbps Cat 6 UTP 100m 1000Base-SX 1Gbps Multi-mode fiber 550m 1000Base-LX 1Gbps Single-mode fiber 2Km 10GBase-T 10Gbps Cat 6a/Cat 7 UTP 100m 10GBase-LX 10Gbps Multi-mode fiber 100m 10GBase-LX 10Gbp Single-mode fiber 10Km

Cable Cost and Bandwidth Cost depend on media type such as copper or fiber optic budget for fiber-optic cabling installation costs for fiber are significantly higher match the performance needs of the users with the cost of the equipment and cabling to achieve the best cost/performance ratio Bandwidth devices in a network have different bandwidth requirements select a media that will provide high bandwidth, and can grow to meet increased bandwidth requirements and newer technologies Ch 10 -

Cable Installation Ease of cable installation varies according to cable types and building architecture access to floor or roof spaces physical size and properties of the cable Cables are usually installed in raceways a raceway is an enclosure or tube that encloses and protects the cable UTP cable is relatively lightweight and flexible and has a small diameter can fit into small spaces Fiber-optic cables contain a thin glass fiber crimps or sharp bends can break the fiber Wireless networks require less cabling Ch 10 -

Types of Interference Electromagnetic interference (EMI) undesirable disturbance that affects an electric circuit due to electromagnetic radiation emitted from an external source such as electrical machines and lighting Radio frequency interference (RFI) radio frequency signals transmitted from nearby radio stations that interfere with the operating frequency of the equipment Wireless is the medium most susceptible to RFI potential sources of interference must be identified Ch 10 -

UTP Cabling Connections Specified by the Electronics Industry Alliance/Telecommunications Industry Association (EIA/TIA) Ch 10 -

Types of Interfaces Media-dependent interface (MDI) pins 1 and 2 are used for transmitting pins 3 and 6 are used for receiving devices such as computers, servers or routers have MDI connections Media-dependent interface, crossover (MDIX) devices that provide LAN connectivity such as hubs or switches use MDIX connections MDIX connections swap the transmit-receive pairs internally end devices connect to hubs or switches using straight-through cables Ch 10 -

Straight-Through UTP Cables A straight-through cable has the same termination at each connector end in accordance with either the T568A or T568B standards Use the same color codes throughout the LAN for consistency in documentation Used for connecting different types of devices switch to router Ethernet port computer to switch computer to hub Ch 10 -

Cross-over UTP Cables A cross-over cable has T568A termination at one end and a T568B termination at the other end transmit pins at each end connect to the receive pins at the other end Used for connecting same types of devices switch to switch switch to hub computer to router Ethernet port router to router Ethernet port computer to computer Ch 10 -

LAN Connections Straight-through UTP cables are used for connecting different types of devices, such as a router LAN interface to a switch Cross-over UTP cables provide connections between same type of devices, such as a switch to another switch Ch 10 -

MDI/MDIX Selection On some devices, ports may have a mechanism that electrically swaps the transmit and receive pairs engage the mechanism to change the port setting Some devices allow for selecting whether a port functions as MDI or MDIX during configuration Many newer devices have an automatic crossover feature device detects the required cable type and configures the interface auto-detection can be enabled by default or via configuration command Ch 10 -

WAN Connections WAN links span extremely long distances over wide geographic areas The chart shows some examples of WAN connections telephone line RJ-11 connectors for dial-up or DSL connection coaxial cable F connector for cable connection serial connections Ch 10 -

Serial Cables One end of the serial cable is either a smart serial connector or a DB-60 connector The other end is a large Winchester 15-pin connector V.35 connection to a Physical layer device such as a CSU/DSU Ch 10 - Smart serial DB-60 Winchester block Smart serial

Types of Devices Data terminal equipment (DTE) a device that receives clocking services from another device device is usually at the customer or the user end of the link Data communications equipment (DCE) a device that supplies the clocking service to another device device is typically at the WAN access provider end of the link Ch 10 -

Serial WAN Connections in the Lab Routers are DTE devices by default, but they can be configured to act as DCE devices Two routers can be connected together using a serial V.35 cable V.35 cables are available in DTE and DCE versions Ch 10 -

Determining the Number of Hosts Every device needs an IP address consider present and future needs Segment the network based on host requirements number of hosts in a network or subnetwork is 2 h – 2 Ch 10 -

Segmenting a Network Manage broadcast traffic divide one large broadcast domain into a number of smaller domains not every host need to receive every broadcast Different network requirements group users that share similar network or computing facilities together in one subnet Security implement different levels of network security based on network addresses Ch 10 -

Creating Subnets Each subnet, is a physical segment, requires a router interface as the gateway for that subnet Number of subnets on one networks is determined using 2 n Ch 10 - n is the number of bits “borrowed” from the host bits to create subnets Fixed length subnet mask one subnet mask for the entire network each physical segment is assigned an unique subnet each subnet has a same number of usable (or valid) host addresses subnet 0 subnet 1 subnet 2 subnet 3 subnet 4

Designing an Address Standard Use addresses that fit a common pattern across all subnets can assist troubleshooting and expedite adding new hosts Hosts can be categorized as general users, special users, network resources, router LAN interfaces, router WAN links and management access Ch 10 - Document the IP addressing scheme

Case Study 1 Ch 10 - Calculating Addresses

Network Requirements WAN link router-to-router connection requires 2 host addresses There are 4 subnetworks in this topology student, instructor, administrator and WAN Ch 10 - LAN Computers & servers Router (LAN gateway) Switches (management) Total Student 460 1 20 481 Instructor 64 1 4 69 Administrator 20 + 1 1 1 23

Fixed Length Subnet Mask Require 9 host bits to support the largest number of host addresses 2 9 – 2 = 510 usable host addresses subnet mask is 255.255.254.0 (or /23 prefix) 2 bits are assigned for subnets  2 2 = 4 subnets Ch 10 -

Variable Length Subnet Mask 172.16.0.0/22 is assigned to this network Refer to chapter 6, p51 on Using VLSM Ch 10 -

Variable Length Subnet Mask (cont’d) Require 9 host bits to support the largest number of hosts mask is /23 prefix 1 bit is used for subnet to create 2 subnets 172.16.0.0/23 (subnet 0) 172.16.2.0/23 (subnet 1) Assign 172.16.0.0/23 (subnet 0) to Student LAN Instructor LAN has the next fewer hosts, i.e. 69 hosts require 7 host bits to accommodate 69 hosts Use 172.16.2.0/23 to create 4 more subnets 172.16.2.0/25 (subnet 0) 172.16.2.128/25 (subnet 1) 172.16.3.0 /25 (subnet 2) 172.16.3.128/25 (subnet 3) Ch 10 -

Case Study 2 Ch 10 - Calculating Addresses

VLSM Keep 5 host bits to accommodate the largest number of hosts 2 5 – 2 = 30 usable host addresses 3 bits are used to create 8 subnets (2 3 – 2) Network B will use 192.168.1.0/27 (subnet 0) valid range of host addresses is 192.168.1.1 to 192.168.1.30 Network E will use 192.168.1.32/27 (subnet 1) valid range of host addresses is 192.168.1.33 to 192.168.1.62 Network A will use 192.168.1.64/28 (subnet 0 in subnet 2) valid range of host addresses is 192.168.1.65 to 192.168.1.78 Network D will use 192.168.1.80/28 (subnet 1 in subnet 2) valid range of host addresses is 192.168.1.81 to 192.168.1.94 Network C will use 192.168.1.96/30 (subnet 0 in subnet 3) valid range of host addresses is 192.168.1.97 to 192.168.1.98 Ch 10 -

Creating Subnets Ch 10 - 128 64 32 16 8 4 2 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 1 1 0 0 0 0 0 0 1 2 3

Device Interfaces LAN interfaces used for connecting UTP cables that terminate LAN devices such as computers, switches and routers AUI, Ethernet and FastEthernet WAN interfaces used for connecting WAN devices to CSU/DSU serial and BRI Ch 10 - Console interface provide configuration to the device Auxiliary (AUX) interface a modem is connected to the interface for remote management

Device Management Connection A RJ-45 to DB-9 or RJ-45 to DB-25 adaptor is connected to the EIA/TIA-232 serial port of the PC a rollover cable is used to connect the adapter to the device console The PC runs a program called a terminal emulator terminal emulator program, such as HyperTerminal, is used to access the functions of a networking device COM port settings are 9600 bps, 8 data bits, no parity, 1 stop bit and no flow control This provides out-of-band console access AUX port may be used for a modem-connected console Ch 10 -

Accessing the Device Console Connect the RJ-45 to DB-9 adapter to the console port using a rollover cable newer computers that do not have an EIA/TIA-232 serial interface will need a USB-to-serial adapter The HyperTerminal program can be accessed via Start  All Programs  Accessories  Communications select the serial COM port and configure the port settings as shown Power on the device and the boot-up sequence will be displayed in the HyperTerminal window Ch 10 -

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