Chapter 10 Planning and Cabling Network

        I learned that before we can form a functioning network we must connect end devices and intermediary devices via cable or wireless connection.It is this network that will support our communication in the human network. Choosing the appropriate

device is a big thing to consider in froming functioning network.Routers are the primary devices used to interconnect networks. Each port on a router connects to a different network and routes packets between the networks. Routers have the ability to break up broadcast domains and collision domains.outers are also used to interconnect networks that use different technologies. They can have both LAN and WAN interfaces.

The router's LAN interfaces allow routers to connect to the LAN media. This is usually UTP cabling, but modules can be added for using fiber-optics. Depending on the series or model of router, there can be multiple interface types for connection of LAN and WAN cabling. To create a LAN, we need to select the appropriate devices to connect the end device to the network. The two most common devices used are hubs and switches. A hub receives a signal, regenerates it, and sends the signal over all ports. The use of hubs creates a logical bus. This means that the LAN uses multiaccess media. The ports use a shared bandwidth approach and often have reduced performance in the LAN due to collisions and recovery. Although multiple hubs can be interconnected, they remain a single collision domain.A switch receives a frame and regenerates each bit of the frame on to the appropriate destination port. This device is used to segment a network into multiple collision domains. Unlike the hub, a switch reduces the collisions on a LAN.When selecting a device for a particular LAN, there are a number of factors that need to be considered. These factors include; cost,speed and types of ports/interface,expandability,manageably,additional features and services.When planning the installation of LAN cabling, there are four physical areas to consider; work area, telecommunications room, also known as the distribution facility, backbone cabling, also known as vertical cabling, distribution cabling, also known as horizontal cabling.Horizontal cabling refers to the cables connecting the telecommunication rooms with the work areas. The maximum length for a cable from a termination point in the telecommunication room to the termination at the work area outlet must not exceed 90 meters. This 90 meter maximum horizontal cabling distance is referred to as the permanent link because it is installed in the building structure. The horizontal media runs from a patch panel in the telecommunications room to a wall jack in each work area. Connections to the devices are made with patch cables.Backbone cabling refers to the cabling used to connect the telecommunication rooms to the equipment rooms, where the servers are often located. Backbone cabling also interconnects multiple telecommunications rooms throughout the facility. These cables are sometimes routed outside the building to the WAN connection or ISP. Backbones, or vertical cabling, are used for aggregated traffic, such as traffic to and from the Internet and access to corporate resources at a remote location. A large portion of the traffic from the various work areas will use the backbone cabling to access resources outside the area or facility. Therefore, backbones typically require high bandwidth media such as fiber-optic cabling. Choosing the cables necessary to make a successful LAN or WAN connection requires consideration of the different media types. As you recall, there are many different Physical layer implementations that support multiple media types: UTP (Category 5, 5e, 6, and 7), fiber-optics, wireless.The total length of cable required to connect a device includes all cables from the end devices in the work area to the intermediary device in the telecommunication room (usually a switch). Attenuation is reduction of the strength of a signal as it moves down a media. The longer the media, the more attenuation will affect the signal. At some point, the signal will not be detectable. Cabling distance is a significant factor in data signal performance. Signal attenuation and exposure to possible interference increase with cable length. There are types of interfaces in networking that corresponds to their designed functionality, namely; Straight-through UTP Cables, Crossover UTP Cables. A straight-through cable has connectors on each end that are terminated the same in accordance with either the T568A or T568B standards. Identifying the cable standard used allows you to determine if you have the right cable for the job. More importantly, it is a common practice to use the same color codes throughout the LAN for consistency in documentation.For two devices to communicate through a cable that is directly connected between the two, the transmit terminal of one device needs to be connected to the receive terminal of the other device.The cable must be terminated so the transmit pin, Tx, taking the signal from device A at one end, is wired to the receive pin, Rx, on device B. Similarly, device B's Tx pin must be connected to device A's Rx pin. If the Tx pin on a device is numbered 1, and the Rx pin is numbered 2, the cable connects pin 1 at one end with pin 2 at the other end. These "crossed over" pin connections give this type of cable its name, crossover.The various LAN and WAN media types and their associated cables and connectors were considered so that the most appropriate interconnection decisions can be made.

Determining the number of hosts and subnets in a network required now - and simultaneously planning for future growth - ensures that data communications are available at the best combination of cost and performance.Similarly, a planned and consistently implemented addressing scheme is an important factor in ensuring that networks work well with provisions to scale as needed. Such addressing schemes also facilitate easy configuration and troubleshooting.Terminal access to routers and switches is a means to configure addresses and network features on these devices.