Chapter 11 Configuring and Testing your Network

In this chapter it discusses here the introduction in router configuration using CLI and it requires the use of Internetwork Operating System (IOS). It says that router is also a computer that has a flash memory. The Cisco Internetwork Operating System (IOS) is the system software in Cisco devices. It is the core technology that extends across most of the Cisco product line. The Cisco IOS provides devices with the following network services: Basic routing and switching functions, Reliable and secure access to networked resources, Network scalability. There are several ways to access the CLI environment. The most usual methods are: Console, Telnet or SSH, AUX port. The Cisco IOS is designed as a modal operating system. The CLI uses a hierarchical structure for the modes. In order from top to bottom, the major modes are: User executive mode, Privileged executive mode, Global configuration mode, other specific configuration modes. There are two primary modes of operation the User EXEC, Privileged EXEC. The role of IOS is that it is the OS of the router and IOS is the one who manage the router configuration. The IOS has several forms of help available: Context-sensitive help, Command Syntax Check, Hot Keys and Shortcuts.

Chapter 10 Planning and Cabling Networks

 Chapter 10 Planning and Cabling Networks

                As we discussed earlier the physical layer of the OSI model and the Ethernet in  this chapter it tackles about the basic network media required to make a LAN connection, Identify the types of connections for intermediate and end device connection 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 when using Cisco equipment, Design an addressing scheme for an internetwork and assign ranges for hosts, network devices, and the router interface and Compare and contrast the importance of network designs. As we all know that router, switch, hub are the basic network media to make a LAN connection without them there will be no LAN connection.  In making a connection we also consider what kind of cable we will used to connect intermediate device and the end device it’s either straight-through or cross over cables. There are also some types of cables namely: coaxial, wireless and it has also the port or physical cable like Fast Ethernet and Serial port that can be used in establishing a connection. When selecting a device for a particular LAN, there are a number of factors that need to be considered. These factors include, but are not limited to: Cost, Speed and Types of Ports/Interfaces, Expandability, Manageability, 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, and Distribution cabling, also known as horizontal cabling. The devices that provide LAN connectivity - usually hubs or switches - typically use MDIX (media-dependent interface, crossover) connections. The MDIX cables swap the transmit pairs internally. This swapping allows the end devices to be connected to the hub or switch using a straight-through cable. Connecting different types of devices use a straight-through cable. And when connecting the same type of device, use a crossover cable. Example use straight-through cables for connecting: Switch to router, Computer to switch, Computer to hub, Use crossover cables for connecting: Switch to switch, Switch to hub, Hub to hub, Router to router, Computer to computer, Computer to router. There are types of devices that maintain the link between a sending and a receiving device namely: Data Communications Equipment (DCE) - A device that supplies the clocking services to another device. Typically, this device is at the WAN access provider end of the link. Data Terminal Equipment (DTE) - A device that receives clocking services from another device and adjusts accordingly. Typically, this device is at the WAN customer or user end of the link.

Chapter 10 Planning and Cabling Networks

 Chapter 10 Planning and Cabling Networks

                As we discussed earlier the physical layer of the OSI model and the Ethernet in  this chapter it tackles about the basic network media required to make a LAN connection, Identify the types of connections for intermediate and end device connection 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 when using Cisco equipment, Design an addressing scheme for an internetwork and assign ranges for hosts, network devices, and the router interface and Compare and contrast the importance of network designs. As we all know that router, switch, hub are the basic network media to make a LAN connection without them there will be no LAN connection.  In making a connection we also consider what kind of cable we will used to connect intermediate device and the end device it’s either straight-through or cross over cables. There are also some types of cables namely: coaxial, wireless and it has also the port or physical cable like Fast Ethernet and Serial port that can be used in establishing a connection. When selecting a device for a particular LAN, there are a number of factors that need to be considered. These factors include, but are not limited to: Cost, Speed and Types of Ports/Interfaces, Expandability, Manageability, 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, and Distribution cabling, also known as horizontal cabling. The devices that provide LAN connectivity - usually hubs or switches - typically use MDIX (media-dependent interface, crossover) connections. The MDIX cables swap the transmit pairs internally. This swapping allows the end devices to be connected to the hub or switch using a straight-through cable. Connecting different types of devices use a straight-through cable. And when connecting the same type of device, use a crossover cable. Example use straight-through cables for connecting: Switch to router, Computer to switch, Computer to hub, Use crossover cables for connecting: Switch to switch, Switch to hub, Hub to hub, Router to router, Computer to computer, Computer to router. There are types of devices that maintain the link between a sending and a receiving device namely: Data Communications Equipment (DCE) - A device that supplies the clocking services to another device. Typically, this device is at the WAN access provider end of the link. Data Terminal Equipment (DTE) - A device that receives clocking services from another device and adjusts accordingly. Typically, this device is at the WAN customer or user end of the link.

Chapter 9 Ethernet

Chapter 9 Ethernet

               

In this chapter it explains about how the Ethernet evolve from the topology where its physical is from bus to star. And the first Ethernet was developed in 1980 by a consortium of Digital Equipment Corporation, Intel, and Xerox (DIX). The foundation for Ethernet technology was first established in 1970 with a program called Alohanet.  Alohanet was a digital radio network designed to transmit information over a shared radio frequency between the Hawaiian Islands. The first version of Ethernet incorporated a media access method known as Carrier Sense Multiple Access with Collision Detection (CSMA/CD). Ethernet is a predominant it can found in the datalink and physical layer of the OSI model. Data link has two sub layer the LLC or Logic Link Control and it has an IEEE standard of 802.2 and the second sublayer of the datalink is the MAC or Media Access Control that has a standard of 802.3. . The Data Link sublayers contribute significantly to technological compatibility and computer communications. The MAC sublayer is concerned with the physical components that will be used to communicate the information and prepares the data for transmission over the media. UTP patch panels in a rack, Ethernet switches, Ethernet fiber connectors, and the Ethernet switch are the Physical devices that are used in Ethernet. It was also discuss here the migration of Ethernet in using switches as a replace from hub to perform the task faster and it start the introduction of full duplex. The Ethernet Timing or the Delay and latency of Ethernet were also discussed here from sending to receiving of data. An Ethernet frame takes a measurerable time to travel (TTL) from the sending device to their receiver. Each intermediary device contributes on the overall latency.  CSMA/CD controls access to the shared media. If there is a collision, it is detected and frames are retransmitted.

Datacom Chapter 8 ( The OSI Physical Layer )

Chapter 8

 The OSI Physical Layer

OSI was define as the international standardization program created by ISO and ITU-T to develop standards for data networking that facilitate multivendor equipment interoperability and OSI model has seven layer that provide guidelines in representation of network operation namely: Physical, Data Link, Network, Transport, Session, Presentation, and Application. In this chapter it discusses the general function of physical layer as well as the standard and protocol that manage the transmission of data across the media. It introduces the signal and the purpose of the Physical Layer which is to create the electrical, optical, or microwave signal that represents the bits in each frame. Media as we all know that it is a single cable connecting one computer to another like UTP where the signal was sent or carried. There are three basic forms of network media namely: Copper cable, Fiber and wireless. Data transfer can be measured in three ways: Bandwidth- which is the amount of data that can be transmitted in a certain amount of time, Throughput- which is the amount of digital data per tome unit that is delivered from one node to another or the actual network performance, and the last which is the Goodput- define as the number of useful bits per unit of time from a certain source address to a certain destination, excluding protocol overhead, and excluding retransmitted data packets or it is measure of the transfer of usable data after protocol overhead traffic has been removed. Physical Layer is concerned with network media and signaling figure below shows some of the characteristic of networking media.

Copper is one of the basic and common network media being used in networking. Here are some types of copper media: the Coaxial cable is a single conductor that runs through the center of the cable that is encased by, but insulated from, the other shield, the RJ-45 connections which is used widely in LANs with one type of media and in some WANs with another media type, and unshielded twisted-pair cable used in Ethernet LANs, consist of four pairs-coded wires that have been twisted together and then encased in a flexible plastic sheath. The purpose outer jacket part of the unshielded twisted pair (UTP) cable is to protects the wire copper from physical damage, while the twisted pair is to protect the signal from interference and the color-coded plastic insulation is an electrically isolates wires from each other and identifies each pair. UTP cable with RJ-45 is a common copper- based medium for interconnecting networks devices. There are three main cable types that are obtained by using specific wiring conventions namely: Ethernet Straight-through its standard arrangement is both end T568A and both end T568B and it connect to a network host to a network device such as a switch or hub, Ethernet Crossover its standard arrangement is one end T568A other end T568B and it connecting two network hosts or intermediary devices, and the last cable types is the rollover which has the standard of cisco proprietary and it connect a workstation serial port to a router console port using an adaptor. There are also two other types of copper cable the coaxial and shielded twisted pair. Fiber media is a medium that uses glass or plastic threads to transmit data that capable of transmitting electric signals into light waves. Wireless media carry electromagnetic signals at radio and microwave frequencies that represent the binary digits data communication and its technology work well in open environments and network security is a major component of wireless network administration. Here are the wireless media standards and types: WI-FI, Bluetooth, WIMAX, and the GSM.