Demonstrate an understanding of Wide Area Networks (WAN`s), comparing them with Local Area Networks (LAN`s) 114061

PURPOSE OF THE UNIT STANDARD This unit standard is intended To provide fundamental knowledge of the areas covered For those entering the workplace in the area of Data Communications & Networking. As additional knowledge for those wanting to understand the areas covered.

People credited with this unit standard are able to: Explain wide area computer networks (WAN`s) Evaluate a (WAN) Explain network administration The performance of all elements is to a standard that allows for further learning in this area.

LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING The credit value of this unit is based on a person having prior knowledge and skills to: Demonstrate an understanding of fundamental mathematics (at least NQF level 3). Demonstrate PC competency skills (End-User Computing unit Standards, at least up to NQF level 3.). Describe data communications. Demonstrate an understanding of local area computer networks, by installing a networked workstation.

UNIT STANDARD RANGE N/A

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INDEX Competence Requirements Page Unit Standard 114061 alignment index Here you will find the different outcomes explained which you need to be 23 proved competent in, in order to complete the Unit Standard 114061. Unit Standard 114061 25 Explain wide area computer networks (WAN`s) 29 Evaluate a wide area (WAN) 41 Explain Network Administration 50 Self-assessment Once you have completed all the questions after being facilitated, you need to check the progress you have made. If you feel that you are competent in the areas mentioned, you may tick the blocks, if however you feel that you 87 require additional knowledge, you need to indicate so in the block below. Show this to your facilitator and make the necessary arrangements to assist you to become competent.

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Unit Standard 114061 – Alignment Index SPECIFIC OUTCOMES AND RELATED ASSESSMENT CRITERIA SO 1 EXPLAIN WIDE AREA COMPUTER NETWORKS (WAN`S) The explanation identifies the components of a WAN and outlines their purpose. Cables, AC 1 cards, terminators, connectors, boot ROM, hubs, repeaters, servers. (at least 3) AC 2 The explanation identifies the purpose of a WAN. AC 3 The explanation identifies and compares WAN configurations. (Star, Bus, Ring) AC 4 The explanation identifies and compares WAN protocols. (, TCP/IP, SNA) The explanation identifies and compares WAN transport media. (; ; AC 5 Optic fibre; (at least 2)) EVALUATE A WIDE AREA COMPUTER NETWORK (WAN). (NETWORK MUST INCLUDE MULTIPLE SITES SO 2 CONNECTED VIA CIRCUIT / ) AC 1 The evaluation identifies the method of implementation of the WAN The evaluation distinguishes categories of the network components, their functions & AC 2 examples. (Hardware, software, communications media, carriers) The evaluation identifies and explains features and constraints of the network from a AC 3 functional perspective AC 4 The evaluation assesses the suitability of the network for its use AC 5 The evaluation proposes and compares alternative network designs SO 3 EXPLAIN NETWORK ADMINISTRATION The explanation identifies the tasks involved and outlines their requirements. (Technical AC 1 control, performance monitoring) The explanation outlines, for a range of factors, how response times are affected. (Speed of AC 2 devices, , , queuing, processing time, priorities at host and nodes, message size) The explanation outlines the principles of network . (Inter-network protocols, AC 3 gateways) The explanation outlines and explains network security administration procedures. AC 4 (Generation, encryption, keys, passwords, logs, audits) AC 5 Network administration documentation is completed

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CRITICAL CROSS FIELD OUTCOMES UNIT STANDARD CCFO WORKING Work effectively with others as a member of an organisation. UNIT STANDARD CCFO ORGANISING Organise and manage him/her self and his/her activities responsibly and effectively. UNIT STANDARD CCFO COLLECTING Collect, analyse, organise, and critically evaluate information. UNIT STANDARD CCFO SCIENCE Use science and technology effectively and critically, showing responsibility towards the environment and health of others. UNIT STANDARD CCFO DEMONSTRATING Demonstrate an understanding of the world as a set of related systems by recognising that problem solving contexts do not exists in isolation. UNIT STANDARD CCFO CONTRIBUTING Contribute to his/her full personal development and the social and economic development of the society at large by being aware of the importance of: reflecting on and exploring a variety of strategies to learn more effectively, exploring education and career opportunities and developing entrepreneurial opportunities. ESSENTIAL EMBEDDED KNOWLEDGE

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All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.

SOUTH AFRICAN QUALIFICATIONS AUTHORITY REGISTERED UNIT STANDARD:

Demonstrate an understanding of Wide Area Computer Networks (WAN`s), comparing them with Local Area Networks (LAN`s)

SAQA ID UNIT STANDARD TITLE 114061 Demonstrate an understanding of Wide Area Computer Networks (WAN`s), comparing them with Local Area Networks (LAN`s) ORIGINATOR SGB Information Systems and Technology PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY - FIELD SUBFIELD Field 10 - Physical, Mathematical, Computer and Life Sciences Information Technology and Computer Sciences ABET UNIT STANDARD PRE-2009 NQF LEVEL NQF LEVEL CREDITS BAND TYPE Undefined Regular Level 5 Level TBA: Pre-2009 was 5 L5 REGISTRATION STATUS REGISTRATION START REGISTRATION END SAQA DECISION DATE DATE NUMBER Reregistered 2018-07-01 2023-06-30 SAQA 06120/18 LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT 2024-06-30 2027-06-30

In all of the tables in this document, both the pre-2009 NQF Level and the NQF Level is shown. In the text (purpose statements, qualification rules, etc), any references to NQF Levels are to the pre-2009 levels unless specifically stated otherwise.

This unit standard does not replace any other unit standard and is not replaced by any other unit standard.

PURPOSE OF THE UNIT STANDARD This unit standard is intended  To provide fundamental knowledge of the areas covered  For those entering the workplace in the area of Data Communications & Networking.  As additional knowledge for those wanting to understand the areas covered.

People credited with this unit standard are able to:  Explain wide area computer networks (WAN`s)  Evaluate a wide area network (WAN)  Explain network administrationThe performance of all elements is to a standard that allows for further learning in this area.

LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING The credit value of this unit is based on a person having prior knowledge and skills to:  Demonstrate an understanding of fundamental mathematics (at least NQF level 3).  Demonstrate PC competency skills (End-User Computing unit Standards, at least up to NQF level 3.).  Describe data communications.  Demonstrate an understanding of local area computer networks, by installing a networked workstation.

UNIT STANDARD RANGE

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N/A

Specific Outcomes and Assessment Criteria:

SPECIFIC OUTCOME 1 Explain wide area computer networks (WAN`s).

ASSESSMENT CRITERIA

ASSESSMENT CRITERION 1 1. The explanation identifies the components of a WAN and outlines their purpose. ASSESSMENT CRITERION RANGE Cables, cards, terminators, connectors, boot ROM, hubs, repeaters, servers. (at least 3).

ASSESSMENT CRITERION 2 2. The explanation identifies the purpose of a WAN.

ASSESSMENT CRITERION 3 3. The explanation identifies and compares WAN configurations. ASSESSMENT CRITERION RANGE Star, Bus, Ring

ASSESSMENT CRITERION 4 4. The explanation identifies and compares WAN protocols. ASSESSMENT CRITERION RANGE Ethernet, TCP/IP, SNA

ASSESSMENT CRITERION 5 5. The explanation identifies and compares WAN transport media. ASSESSMENT CRITERION RANGE Twisted pair; Coaxial cable; Optic fibre; Wireless (at least 2).

SPECIFIC OUTCOME 2 Evaluate a wide area computer network (WAN). OUTCOME RANGE Network must include multiple sites connected via circuit / packet switching.

ASSESSMENT CRITERIA

ASSESSMENT CRITERION 1 1. The evaluation identifies the method of implementation of the WAN.

ASSESSMENT CRITERION 2 2. The evaluation distinguishes categories of the network components, their functions & examples. ASSESSMENT CRITERION RANGE Hardware, software, communications media, carriers.

ASSESSMENT CRITERION 3 3. The evaluation identifies and explains features and constraints of the network from a functional perspective.

ASSESSMENT CRITERION 4 4. The evaluation assesses the suitability of the network for its use.

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ASSESSMENT CRITERION 5 5. The evaluation proposes and compares alternative network designs.

SPECIFIC OUTCOME 3 Explain Network Administration.

ASSESSMENT CRITERIA

ASSESSMENT CRITERION 1 1. The explanation identifies the tasks involved and outlines their requirements. ASSESSMENT CRITERION RANGE Technical control, performance monitoring.

ASSESSMENT CRITERION 2 2. The explanation outlines, for a range of factors, how response times are affected. ASSESSMENT CRITERION RANGE Speed of devices, bandwidth, routing, queuing, processing time, priorities at host and nodes, message size.

ASSESSMENT CRITERION 3 3. The explanation outlines the principles of network interconnections. ASSESSMENT CRITERION RANGE Inter-network protocols, gateways.

ASSESSMENT CRITERION 4 4. The explanation outlines and explains network security administration procedures. ASSESSMENT CRITERION RANGE Generation, encryption, keys, passwords, logs, audits.

ASSESSMENT CRITERION 5 5. Network administration documentation is completed.

UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS The relevant Education and Training Quality Authority (ETQA) must accredit providers before they can offer programs of education and training assessed against unit standards.

Moderation Process:

Moderation of assessment will be overseen by the relevant ETQA according to the moderation guidelines in the relevant qualification and the agreed ETQA procedures.

UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 1. Performance of all elements is to be carried out in accordance with organisation standards and procedures, unless otherwise stated. Organisation standards and procedures may cover: quality assurance, documentation, security, communication, health and safety, and personal behaviour. An example of the standards expected is the standards found in ISO 9000 Certified Organisations. 2. Performance of all elements complies with the laws of South Africa, especially with regard to copyright, privacy, health and safety, and consumer rights. 3. All activities must comply with any policies, procedures and requirements of the organisations involved, the ethical codes of relevant professional bodies and any relevant legislative and/ or regulatory requirements 4. Performance of all elements should be performed with a solid understanding of the use of development tools needed in the areas applicable to the unit standard. Examples of such tools are, but is not limited to CASE tools, programming language editors with syntax checking, program source version control systems.

UNIT STANDARD DEVELOPMENTAL OUTCOME N/A

UNIT STANDARD LINKAGES

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N/A

Critical Cross-field Outcomes (CCFO):

UNIT STANDARD CCFO WORKING Work effectively with others as a member of an organisation.

UNIT STANDARD CCFO ORGANISING Organise and manage him/her self and his/her activities responsibly and effectively.

UNIT STANDARD CCFO COLLECTING Collect, analyse, organise, and critically evaluate information.

UNIT STANDARD CCFO SCIENCE Use science and technology effectively and critically, showing responsibility towards the environment and health of others.

UNIT STANDARD CCFO DEMONSTRATING Demonstrate an understanding of the world as a set of related systems by recognising that problem solving contexts do not exists in isolation.

UNIT STANDARD CCFO CONTRIBUTING Contribute to his/her full personal development and the social and economic development of the society at large by being aware of the importance of: reflecting on and exploring a variety of strategies to learn more effectively, exploring education and career opportunities and developing entrepreneurial opportunities.

UNIT STANDARD ASSESSOR CRITERIA N/A

REREGISTRATION HISTORY As per the SAQA Board decision/s at that time, this unit standard was Reregistered in 2012; 2015.

UNIT STANDARD NOTES Supplementary information:

1. "LAN" refers to a single network of personal within the same areasuch as an office or building. 2. "WAN" refers to a network of computers that are physically remote from eachother and are connected via third party carriers. 3. "Current Industry Practice" refers to a practice used and recommended by anan organisation involved in the computer industry. 4. Where not specified otherwise, all options in the range statement must be covered to confirm that a learner is competent in the specific outcome.

Sub-Sub-Field (Domain): Computer Operations.

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Explain and Evaluate wide area computer networks Time: 180 minutes Activity: Self and Group

AC 1 he explanation identifies the components of a WAN and outlines their purpose. T A WAN (Wide Area Network) is a computer network that spans a relatively large geographical area. Typically, a WAN consists of two or more local-area networks (LANs). Computers connected to a wide-area network are often connected through public networks, such as the system. They can also be connected through leased lines or satellites. The largest WAN in existence is the .

Wide Area Network (WAN) is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries [1]). Or, less formally, a network that uses routers and public communications links [1]. Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs) which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well- known example of a WAN is the Internet.

AC 2 he explanation identifies the purpose of a WAN WANs are used to connect LANs and other types of networks together, so that users T and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connections from an organization's LAN to the Internet. WANs are often built using leased lines.

At each end of the , a connects to the LAN on one side and a hub within the WAN on the other. Leased lines can be very expensive. Instead of using leased lines, WANs can also be built using less costly or packet switching methods. Network protocols including TCP/IP deliver transport and addressing functions.

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Protocols including Packet over SONET/SDH, MPLS, ATM and are often used by service providers to deliver the links that are used in WANs. X.25 was an important early WANSACHMO protocol, and is often considered to be the "grandfather" of Frame Relay as many of the underlying protocols and functions of X.25 are still in use today (with upgrades) by Frame Relay.

Academic research into wide area networks can be broken down into three areas: Mathematical models, network emulation and network simulation. Performance improvements are sometimes delivered via WAFS or WAN Optimization.

What Is a WAN? A WAN is a data communications network that covers a relatively broad geographic area and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the layer, and the network layer. Figure 3-1 illustrates the relationship between the common WAN technologies and the OSI model. Figure 3-1 WAN Technologies Operate at the Lowest Levels of the OSI Model

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AC 3 he explanation identifies and compares WAN configurations Point-to-Point Links T A point-to-point link provides a single, pre-established WAN communications path from the customer premises through a carrier network, such as a , to a remote network. Point-to-point lines are usually leased from a carrier and thus are often called leased lines.

For a point-to-point line, the carrier allocates pairs of wire and facility hardware to your line only. These circuits are generally priced based on bandwidth required and distance between the two connected points. Point-to-point links are generally more expensive than shared services such as Frame Relay. Figure below illustrates a typical point-to-point link through a WAN.

Figure 3-2 A Typical Point-to-Point Link Operates Through a WAN to a Remote Network

Circuit Switching Switched circuits allow data connections that can be initiated when needed and terminated when communication is complete. This works much like a normal telephone line works for voice communication. Integrated Services Digital Network (ISDN) is a good example of circuit switching.

When a router has data for a remote site, the switched circuit is initiated with the circuit number of the remote network. In the case of ISDN circuits, the device actually places a call to the of the remote ISDN circuit. When the two networks are connected and authenticated, they can transfer data. When the data transmission is complete, the call can be terminated.

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The figure on the following page A Circuit-Switched WAN Undergoes a Process Similar to That Used for a

Packet Switching Packet switching is a WAN technology in which users share common carrier resources. Because this allows the carrier to make more efficient use of its infrastructure, the cost to the customer is generally much better than with point-to-point lines. In a packet switching setup, networks have connections into the carrier's network, and many customers share the carrier's network.

The carrier can then create virtual circuits between customers' sites by which packets of data are delivered from one to the other through the network. The section of the carrier's network that is shared is often referred to as a cloud.

Some examples of packet-switching networks include Asynchronous Transfer Mode (ATM), Frame Relay, Switched Multimegabit Data Services (SMDS), and X.25. Figure 3-4 shows an example packet-switched circuit. The virtual connections between customer sites are often referred to as a . Figure 3-4 Packet Switching Transfers Packets Across a Carrier Network

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WAN Virtual Circuits A virtual circuit is a logical circuit created within a shared network between two network devices. Two types of virtual circuits exist: switched virtual circuits (SVCs) and permanent virtual circuits (PVCs).

SVCs are virtual circuits that are dynamically established on demand and terminated when transmission is complete. Communication over an SVC consists of three phases: circuit establishment, data transfer, and circuit termination. The establishment phase involves creating the virtual circuit between the source and destination devices.

Data transfer involves transmitting data between the devices over the virtual circuit, and the circuit termination phase involves tearing down the virtual circuit between the source and destination devices. SVCs are used in situations in which data transmission between devices is sporadic, largely because SVCs increase bandwidth used due to the circuit establishment and termination phases, but they decrease the cost associated with constant virtual circuit availability.

PVC is a permanently established virtual circuit that consists of one mode: data transfer. PVCs are used in situations in which data transfer between devices is constant. PVCs decrease the bandwidth use associated with the establishment and termination of virtual circuits, but they increase costs due to constant virtual circuit availability. PVCs are generally configured by the service provider when an order is placed for service.

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AC 4 he explanation identifies and compares WAN protocols. WAN Dialup Services T Dialup services offer cost-effective methods for connectivity across WANs. Two popular dialup implementations are dial-on-demand routing (DDR) and dial backup. DDR is a technique whereby a router can dynamically initiate a call on a switched circuit when it needs to send data.

In a DDR setup, the router is configured to initiate the call when certain criteria are met, such as a particular type of network traffic needing to be transmitted. When the connection is made, traffic passes over the line. The router configuration specifies an idle timer that tells the router to drop the connection when the circuit has remained idle for a certain period.

Dial backup is another way of configuring DDR. However, in dial backup, the switched circuit is used to provide backup service for another type of circuit, such as point-to-point or packet switching.

The router is configured so that when a failure is detected on the primary circuit, the dial backup line is initiated. The dial backup line then supports the WAN connection until the primary circuit is restored. When this occurs, the dial backup connection is terminated.

WAN Devices WANs use numerous types of devices that are specific to WAN environments. WAN switches, access servers, , CSU/DSUs, and ISDN terminal adapters are discussed in the following sections. Other devices found in WAN environments that are used in WAN implementations include routers, ATM switches, and multiplexers.

WAN Switch A WAN switch is a multiport device used in carrier networks. These devices typically switch such traffic as Frame Relay, X.25, and SMDS, and operate at the data link layer of the OSI reference model. Figure 3-5 illustrates two routers at remote ends of a WAN that are connected by WAN switches.

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Access Server An access server acts as a concentration point for dial-in and dial- out connections. Figure 3-6 illustrates an access server concentrating dial-out connections into a WAN. Figure 3-6 An Access Server Concentrates Dial-Out Connections into a WAN.

Modem A is a device that interprets digital and analogue signals, enabling data to be transmitted over voice-grade telephone lines. At the source, digital signals are converted to a form suitable for transmission over analogue communication facilities. At the destination, these analogue signals are returned to their digital form. Figure 3-7 illustrates a simple modem-to-modem connection through a WAN. Figure 3-7 A Modem Connection Through a WAN Handles Analogue and Digital Signals

CSU/DSU A /digital service unit (CSU/DSU) is a digital-interface device used to connect a router to a digital circuit like a T1. The CSU/DSU also provides signal timing for communication between these devices. Figure 3-8 illustrates the placement of the CSU/DSU in a WAN implementation. Figure 3-8 The CSU/DSU Stands Between the Switch and the Terminal

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ISDN Terminal Adapter An ISDN terminal adapter is a device used to connect ISDN Basic Rate Interface (BRI) connections to other interfaces, such as EIA/TIA-232 on a router. A terminal adapter is essentially an ISDN modem, although it is called a terminal adapter because it does not actually convert analog to digital signals. Figure 3-9 illustrates the placement of the terminal adapter in an ISDN environment. Figure 3-9 The Terminal Adapter Connects the ISDN Terminal Adapter to Other Interfaces

WAN Topologies Topologies are either physical or logical. There are four principal topologies used in LANs.

Bus topology: All devices are connected to a central cable, called the bus or backbone. Bus networks are relatively inexpensive and easy to install for small networks. Ethernet systems use a bus topology.

Ring topology : All devices are connected to one another in the shape of a closed loop, so that each device is connected directly to two other devices, one on either side of it. Ring topologies are relatively expensive and difficult to install, but they offer high bandwidth and can span large distances.

Star topology: All devices are connected to a central hub. Star networks are relatively easy to install and manage, but bottlenecks can occur because all data must pass through the hub.

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Tree topology: A tree topology combines characteristics of linear bus and star topologies. It consists of groups of star-configured workstations connected to a linear bus backbone cable. These topologies can also be mixed. For example, a bus-star network consists of a high- bandwidth bus, called the backbone, which connects a collection of slower-bandwidth star segments.

WAN connectivity options Transmission rate usually range from 1200 bits/second to 6 Mbit/s, although some connections such as ATM and Leased lines can reach speeds greater than 156 Mbit/s . Typical communication links used in WANs are telephone lines, links & satellite channels.

Recently with the proliferation of low cost of Internet connectivity many companies and organizations have turned to VPN to interconnect their networks, creating a WAN in that way. Companies such as Cisco and Check Point offer solutions to create VPN networks.

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AC 5 he explanation identifies and compares WAN transport media

Sample Bandwidth Option: Description Advantages Disadvantages protocols T range used

Point-to-Point connection PPP, Leased between two HDLC, Most secure Expensive line computers or SDLC, Local Area HNAS Networks (LANs)

A dedicated circuit path is created Circuit between end Less 28 Kb/s - PPP, Call Setup switching points. Best Expensive 144 Kb/s ISDN example is dialup connections

Devices transport packets via a shared single point-to-point or point-to- multipoint link across a carrier X.25 Packet Shared media internetwork. Frame- switching across link Variable length Relay packets are transmitted over Permanent Virtual Circuits (PVC) or Switched Virtual Circuits (SVC)

Similar to packet best for Overhead can switching, but simultaneous be ATM

uses fixed length use of Voice considerable

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cells instead of and data variable length packets. Data is divided into fixed- length cells and then transported across virtual circuits

WWAN, which stands for Wireless Wide Area Network, is a form of . A WWAN differs from a WLAN (e.g. wireless LAN) because it uses technologies such as WIMAX, UMTS, GPRS, CDMA2000, GSM, CDPD, Mobitex, HSDPA or to transfer data. It can use also LMDS and Wi-Fi to connect to the Internet. These cellular technologies are offered regionally, nationwide, or even globally and are provided by a wireless service provider for a monthly usage fee. Various computers now have integrated WWAN capabilities (Such as HSDPA in Centrino). This means that the system has a cellular (GSM/CDMA) built in, which allows the user to send and receive data.

There are two basic means that a mobile network may use to transfer data: Packet-switched Data Networks (GPRS/CDPD) Circuit-switched dial-up connections Since radio communications systems do not provide a physically secure connection path, WWANs typically incorporate sophisticated encryption and authentication methods to make them more secure.

Coaxial cable is an electrical cable consisting of a round conducting wire, surrounded by an insulating spacer, surrounded by a cylindrical conducting sheath, usually surrounded by a final insulating layer (jacket).

It is used as a high-frequency to carry a high-frequency or broadband signal. Because the electromagnetic field carrying the signal exists (ideally) only in the space between the inner and outer conductors, it cannot interfere with or suffer interference from external electromagnetic fields.

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Optical fiber is the most common type of channel for optical communications, however, other types of optical waveguides are used within communications gear, and have even formed the channel of very short distance (e.g. chip-to-chip) links in laboratory trials. The in links are generally light-emitting diodes (LED’s) or laser diodes. Infrared light, rather than visible light is used more commonly, because optical fibres transmit infrared wavelengths with less attenuation and dispersion.

The signal encoding is typically simple intensity , although historically optical phase and have been demonstrated in the lab. The need for periodic signal regeneration was largely superseded by the introduction of the erbium-doped fiber amplifier, which extended link distances at very lower cost.

Wireless Networks While the term wireless network may technically be used to refer to any type of network that is wireless, the term is most commonly used to refer to a network whose interconnections between nodes is implemented without the use of wires, such as a computer network (which is a type of communications network).

Wireless telecommunications networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or "layer" of the network.

One type of wireless network is a WLAN or Wireless . Similar to other wireless devices, it uses radio instead of wires to transmit data back and forth between computers on the same network.

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Evaluate a wide area computer network (WAN) Time: 120 minutes Activity: Self and Group

AC 1 he evaluation identifies the method of implementation of the WAN T A computer network that spans a relatively large geographical area. Typically, a WAN consists of two or more local-area networks (LANs). Computers connected to a wide- area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites. The largest WAN in existence is the Internet.

Wide area networks (WAN) is a network which is spread over a large geographical area with a primary purpose of computer networking. A WAN network connects different small local area LAN and metro area MAN networks. To construct the WAN network, a combination of various network devices such as bridges, switches, and routers are required. The most well-known WAN network is the Internet. WAN network covers cities, states, countries and even continents. WAN can be a public network or a .

WAN Network Design Overview As the network is spread over long distances, reliable and fast transmission media with high bandwidth is required, thus fiber optic cable is mostly used for WAN connectivity. The switching technology used in WAN includes both circuit and packet switching depending upon the network architecture.

The WAN networks are designed in such a way in which the enterprise’s head office will be connected with the branch offices and centralized data center with internet connectivity to all the end users if they have relevance. In this tutorial, we will explore the designing aspects of the WAN networks with the significance of STM links in WAN technology.

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Design Concerns The network should be designed in such a way in which the overall architecture designed should be cost-effective and within the budget. The links used for connectivity should be reliable and in protection. By provisioning protection, if one link fails the network will still be alive by using the protection link. The overall network throughput should come out best and packet delay should be as minimal as possible.

The network should be designed in such a way in which there should be minimal interference, jitter, and packet loss. The basic goal of a well-designed network is to deliver data to the destination host from the source host by using the shortest path. The components equipped in the network should be well utilized and managed properly. A strong firewall system should be used to provide reliable and secure transmission. The , transmission modes, routing policy and the other network parameters should be chosen depending upon the type and need of the system to be implemented.

AC 2 he evaluation distinguishes categories of the network components, T their functions & examples.

A wide area network (WAN) is a telecommunications network that extends over a large geographical area for the primary purpose of computer networking. Wide area networks are often established with leased telecommunication circuits. Business, as well as education and government entities use wide area networks to relay data to staff, students, clients, buyers and suppliers from various locations across the world. In essence, this mode of telecommunication allows a business to effectively carry out its daily function regardless of location. The Internet may be considered a WAN.

Similar types of networks are personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs) which are usually limited to a room, building, campus or specific metropolitan area, respectively.

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Design options The textbook definition of a WAN is a computer network spanning regions, countries, or even the world. However, in terms of the application of computer networking protocols and concepts, it may be best to view WANs as computer networking technologies used to transmit data over long distances, and between different LANs, MANs and other localised computer networking architectures.

This distinction stems from the fact that common LAN technologies operating at lower layers of the OSI model (such as the forms of Ethernet or Wi-Fi) are often designed for physically proximal networks, and thus cannot transmit data over tens, hundreds, or even thousands of miles or kilometres.

WANs do not just necessarily connect physically disparate LANs. A CAN, for example, may have a localized backbone of a WAN technology, which connects different LANs within a campus. This could be to facilitate higher bandwidth applications or provide better functionality for users in the CAN.

WANs are used to connect LANs and other types of networks together so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connections from an organization's LAN to the Internet. WANs are often built using leased lines.

At each end of the leased line, a router connects the LAN on one side with a second router within the LAN on the other. Leased lines can be very expensive. Instead of using leased lines, WANs can also be built using less costly circuit switching or packet switching methods. Network protocols including TCP/IP deliver transport and addressing functions.

Protocols including Packet over SONET/SDH, Multiprotocol Label Switching (MPLS), Asynchronous Transfer Mode (ATM) and Frame Relay are often used by service providers to deliver the links that are used in WANs. X.25 was an important early WAN protocol, and is often considered to be the "grandfather" of Frame Relay as many of the underlying protocols and functions of X.25 are still in use today (with upgrades) by Frame Relay.

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Private networks Of the approximately four billion addresses defined in IPv4, about 18 million addresses in three ranges are reserved for use in private networks. Packets addresses in these ranges are not routable in the public Internet; they are ignored by all public routers. Therefore, private hosts cannot directly communicate with public networks, but require translation at a routing gateway for this purpose.

Reserved private IPv4 network ranges

Number of Name CIDR block Address range Classful description addresses

24-bit 10.0.0.0 – 10.0.0.0/8 16777216 Single Class A. block 10.255.255.255

20-bit 172.16.0.0 – Contiguous range of 16 172.16.0.0/12 1048576 block 172.31.255.255 Class B blocks.

16-bit 192.168.0.0 – Contiguous range of 256 192.168.0.0/16 65536 block 192.168.255.255 Class C blocks.

Since two private networks, e.g., two branch offices, cannot directly interoperate via the public Internet, the two networks must be bridged across the Internet via a (VPN) or an IP tunnel, which encapsulates packets, including their headers containing the private addresses, in a protocol layer during transmission across the public network. Additionally, encapsulated packets may be encrypted for the transmission across public networks to secure the data.

Connection technology Many technologies are available for wide area network links. Examples include circuit- switched telephone lines, transmission, and optical fiber. New developments in technologies have successively increased transmission rates. In ca. 1960, a 110 bit/s (bits per second) line was normal on the edge of the WAN, while core links of 56 kbit/s to 64 kbit/s were considered fast. As of 2014, households are connected to the Internet with Dial-Up, ADSL, Cable, Wimax, or fiber. The speeds that people can currently use range from 28.8 kbit/s through a 28K modem over a telephone connection to speeds as high as 100 Gbit/s over an Ethernet 100GBaseY connection. The following communication and networking technologies have been used to implement WANs.

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Asynchronous Transfer Mode Dial-up internet Fiber-optic communication Frame Relay ISDN Leased line SD-WAN Synchronous X.25

400 Gigabit Ethernet AT&T conducted trials in 2017 for business use of 400 gigabit Ethernet. Researchers Robert Maher, Alex Alvarado, Domaniç Lavery, and Polina Bayvel of University College London were able to increase networking speeds to 1.125 terabits per second. Christos Santis, graduate student Scott Steger, Amnon Yariv, Martin and Eileen Summerfield developed a new laser that quadruples transfer speeds with fiber optics. If these two technologies were combined, then a transfer speed of up to 4.5 terabits per second could potentially be achieved

AC 3 he evaluation identifies and explains features and constraints of the network from a functional perspective T Wide Area Network (WAN): A Wide Area Network (WAN) spans over multiple geographic locations, which is composed of multiple LANs. It is nearly impossible for a small to medium organization (except Network Service Providers) to pull network cables between their two offices in two different countries located 1000s of kilometres away. Network Service Providers (also called as ISPs) provide the connectivity solutions for Wide Area Networks (WAN).

What are the features of wide area network? Centralized monitoring solution with Datadog. A single platform for monitoring and analysing metrics, traces, and logs from your environment. Wide area network is collection of different local area networks, connect different LAN and WAN with each other, typically contain a country or region. Internet is the biggest example of wide area network. WAN is running with

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large variety of protocols and providing different services. The major features of WANs are listed below： Multiple computers are connected together It connect devices that are separated by a broader geographical area than a LAN A WAN usually interconnects multiple LANs Communication links between computers are provided by telephone networks, public data networks, satellite... For perspective, the term Wide Area Network (WAN) arose to describe geographically large interconnections of Local Area Networks (LANs). LANs are the networks that run within a single building or maybe a few nearby structures. They use data link protocols like Ethernet or WiFi that are designed for short distances. In order to connect with offices in other cities, as if they were in your own building, you build a WAN. A WAN is most often created by leasing private lines from telecommunications companies.

The major features of the wide-area network are listed below： Multiple computers are connected together. It connects devices that are separated by a broader geographical area than a LAN. A WAN usually interconnects multiple LANs. Communication links between computers are provided by telephone networks, public data networks, satellites, etc.

AC 4 he evaluation assesses the suitability of the network for its use T A wide area network (WAN) is a data network, usually used for connecting computers, that spans a wide geographical area. WANs can be used to connect cities, states, or even countries. WANs are often used by larger corporations or organizations to facilitate the exchange of data, and in a wide variety of industries corporations with facilities at multiple locations have embraced WANs.

Increasingly, however, even small businesses are utilizing WANs as a way of increasing their communications capabilities. Although WANs serve a purpose similar to that of local area networks (LANs), WANs are structured and operated quite differently.

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The user of a WAN usually does not own the communications lines that connect the remote computer systems; instead, the user subscribes to a service through a telecommunications provider. Unlike LANs, WANs typically do not link individual computers, but rather are used to link LANs. WANs also transmit data at slower speeds than LANs. WANs are also structurally similar to metropolitan area networks (MANs), but provide communications links for distances greater than 50 kilometres.

WANs have existed for decades, but new technologies, services, and applications have developed over the years to dramatically increase their efficacy for business. WANs were originally developed for digital leased-line services carrying only voice, rather than data. As such, they connected the private branch exchanges (PBXs) of remote offices of the same company.

WANs are still used for voice services, but today they are used more frequently for data and image transmission (such as video conferencing). These added applications have spurred significant growth in WAN usage, primarily because of the surge in LAN connections to the wider networks.

How WANS work WANs are either point-to-point, involving a direct connection between two sites, or operate across packet-switched networks, in which data are transmitted in packets over shared circuits. Point-to-point WAN service may involve either analog dial-up lines, in which a modem is used to connect the computer to the telephone line, or dedicated leased digital telephone lines, also known as "private lines."

Analog lines, which may be either part of a public-switched or leased lines, are suitable for batch data transmissions, such as nonurgent order entry and point-of- sale transactions. Dedicated digital phone lines permit uninterrupted, secure data transmission at fixed costs.

Point-to-point WAN service providers include both local telephone companies and long- distance carriers. Packet-switched network services are typically chosen by organizations which have low volumes of data or numerous sites, for which multiple dedicated lines would be too expensive.

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Depending on the service, WANs can be used for almost any data-sharing purpose for which LANs can be used. Slower transmission speeds, however, may make some applications less practical for WANs. The most basic uses of WANs are for electronic mail and file transfer, but WANs can also permit users at remote sites to access and enter data on a central site's database, such as instantaneously updating accounting records.

New types of network-based software that facilitate productivity and production tracking, such as groupware and work-flow automation software, can also be used over WANs. Using groupware, workers at dispersed locations can more easily collaborate on projects. WANs also give remote offices access to a central office's other data communications services, including the Internet.

AC 5 he evaluation proposes and compares alternative network designs. Local Area T Network (LAN), and Wide Area Network (WAN) Local Area Network (LAN): Local Area Network (LAN) is a computer network, which is limited to a small office, single building, multiple buildings inside a campus etc. Typically a Local Area Network (LAN) is a private network owned and maintained by a single organization.

Wide Area Network (WAN): A Wide Area Network (WAN) spans over multiple geographic locations, which is composed of multiple LANs. It is nearly impossible for a small to medium organization (except Network Service Providers) to pull network cables between their two offices in two different countries located 1000s of kilometres away. Network Service Providers (also called as ISPs) provide the connectivity solutions for Wide Area Networks (WAN).

Below image shows two Local Area Networks (LANs), located at two different geographical locations connected via Internet to create a Wide Area Network (WAN). LAN 1 is located in Chennai, India and LAN 2 is located in Manila, Philippines. The aerial distance between Chennai and Manila is about 4,400 Kilometres. It is almost impossible for a small to medium business to draw cables between Chennai and Manila. We normally avail the services of an Internet Service Provider for connectivity between these two offices.

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Differences between Local Area Networks (LANs) and Wide Area Network (WAN) • A Local Area Network (LAN) is a private computer network that connects computers in small physical areas. Example: A small office, A Single building, Multiple buildings inside a campus etc. Wide Area Networks (WAN) is type of computer network to connect offices which are located in different geographical locations. Wide Area Network (WAN) depends mainly on Internet Service Providers (ISPs) for connection solutions. • Local Area Network (LAN) has higher bandwidth rates. Current Local Area Networks (LANs) runs on bandwidths of 100 Mbps, 1 Gbps or 10 Gbps. Wide Area Networks (WAN) has lower bandwidth rates compared with Local Area Network (LAN). Current Wide Area Networks runs on bandwidths of 4 Mbps, 8 Mbps, 20 Mbps, 50 Mbps or 100 Mbps. • Local Area Network (LAN) bandwidth rates are almost constant. Local Area Network (LAN) bandwidth rates are dependent on characteristics of the LAN technology in use (Normally FastEthernet or Gigabit Ethernet). Since most of Wide Area Networks (WAN) connectivity solutions are dependent on Internet Service Providers (ISPs), budget related constraints affect the quality of WAN. • Most of the current Local Area Networks (LANs) use Ethernet as the LAN Standard (FastEthernet 100 Mbps, or Gigabit Ethernet 1/10 Gbps). WAN uses technologies like VPN (Virtual Private Network) over Internet, MPLS, FrameRelay, or Leased Lines as WAN connectivity solutions. • Since Local Area Networks (LANs) are private networks, managed by dedicated local network administrators, Local Area Networks (LANs) are more reliable and secure than Wide Area Networks (WANs). Since Wide Area Networks (WANs) involve 3rd party service providers, WAN networks are less reliable and secure. • Initial set-up costs for Local Area Networks (LANs) are low as the devices required to set up the networks are cheap. Initial set-up costs for Wide Area Networks (WANs) are high, because of the devices (Routers, Firewalls etc), cables and manpower required. • Local Area Networks (LANs) running costs are less Wide Area Networks (WANs) running costs are high. Wide Area Networks (WANs) normally have recurring monthly cost as Service Provider access fees. • Wide Area Networks (WANs) are more congested than Local Area Networks (LANs).

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Network administration Time: 120 minutes Activity: Self and Group

AC 1 he explanation identifies the tasks involved and outlines their requirements T Overview The terms network administrator, network specialist and network analyst designate job positions of engineers involved in computer networks, the people who carry out network administration. Network administrators are basically the network equivalent of system administrators: they maintain the hardware and software that comprises the network.

This normally includes the deployment, configuration, maintenance and monitoring of active network gear: switches, routers, firewalls, etc. Network administration commonly includes activities such as network address assignment, assignment of routing protocols and routing table configuration as well as configuration of authentication and authorization – directory services.

It often includes maintenance of network facilities in individual machines, such as drivers and settings of personal computers as well as printers and such. It sometimes also includes maintenance of certain network servers: file servers, VPN gateways, intrusion detection systems, etc.

Network specialists and analysts concentrate on the network design and security, particularly troubleshooting and/or debugging network-related problems. Their work can also include the maintenance of the network's authorization infrastructure, as well as network backup systems.

Responsibilities of a Network Administrator Communications Plans, defines, designs, develops, coordinates, and implements voice and/or data communication systems. Knowledge of troubleshooting or problem solving, must be able to quickly and correctly diagnose problem and know how best to fix it and communicate the solution to either co-workers or end-users effectively.

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Understand the behaviour of software, hardware and systems in relation to their use of communications technology in order to deploy solutions and to troubleshoot problems. Understanding of regulations and spectrums Strong understanding of radio communications including packet transfer over radio frequencies Maintains current knowledge of technology and voice and data communications systems. Knowledge of the purposes and methods of communication used by employees, servers and systems.

Networking perform network management functions ensure prescribed service-quality objectives are met Knowledge of network and communication hardware and software Knowledge of operating systems and applications and specific methods of network communication Identifies and resolves complex voice and/or data communications network problems; arranges for vendor support if necessary. Understanding of IP and Voice Over IP solutions with respect to network design characteristics and related configuration of hardware and end-user devices Understanding and integration of Metropolitan Area Networks (MAN) Understanding the use of point-to-point radio communications to extend Ethernet network infrastructure to outlying enterprise properties. Understanding of video and surveillance technology

Administration Coordinates voice network services, technical and maintenance support with outside service providers. Particularly with our Internet-facing systems, must have a strong grasp of network security, appliances, infrastructure, and concepts. Knowledge of methods for detecting and preventing intrusion and other security Knowledge of current computer, component, and network security systems and techniques in order to prepare for such attacks and recommend new techniques and methods of defense.

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Researches and evaluates voice and/or data software and hardware, services and other communications equipment; applies hardware and software release upgrades; recommends improved and most efficient hardware, software and procedures. Maintains records and prepares periodic and special reports of work performed. Creates and maintains logical, physical and protocol maps, and backups of all equipment configurations parameters, and network documentation standards and procedures. Server maintenance and troubleshooting. Including software security patches, operating system updates, performance tuning, log analysis, maintaining application updates and bug fixes.

Development Develops communication network plans and strategies including standards, current and future network topology, and capacity planning. Validation of new technologies proposed for use. Conducts customer needs assessments; analyzes costs; develops project plans for communications projects; orders necessary voice and/or data communications equipment; installs and/or coordinates equipment installation, moves and reconfigurations; configures and tests procedures and equipment. Assists in short and long term planning including the development of strategic plans to leverage emerging technology to support future enterprise needs. Meets with vendors to hold product demonstrations and to resolve communication network issues. Provides training to technical support staff in various voice and/or data communication network functions.

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AC 2 he explanation outlines, for a range of factors, how response times are affected. T Bandwidth is the amount of data that can be transmitted in a fixed amount of time. For digital devices, the bandwidth is usually expressed in bits per second (bps) or bytes per second. For analogue devices, the bandwidth is expressed in cycles per second, or Hertz (Hz).

The network administrator will check that the agreed bandwidth of the company is maintained by the appointed Internet Service Provider and that the usage thereof by the company’s staff or other users is in accordance with the company requirements. The bandwidth is particularly important for I/O devices. For example, a fast disk drive can be hampered by a bus with a low bandwidth. This is the main reason that new buses, such as AGP, have been developed for the PC.

Routing, in internetworking, is the process of moving a packet of data from source to destination. Routing is usually performed by a dedicated device called a router. Routing is a key feature of the Internet because it enables messages to pass from one computer to another and eventually reach the target machine. Each intermediary computer performs routing by passing along the message to the next computer.

Part of this process involves analyzing a routing table to determine the best path. Routing is often confused with , which performs a similar function. The principal difference between the two is that bridging occurs at a lower level and is therefore more of a hardware function whereas routing occurs at a higher level where the software component is more important. And because routing occurs at a higher level, it can perform more complex analysis to determine the optimal path for the packet.

The Routing Information Protocol (RIP) is one of the most commonly used interior gateway protocol (IGP) routing protocols on internal networks (and to a lesser extent, networks connected to the Internet), which helps routers dynamically adapt to changes of network connections by communicating information about which networks each router can reach and how far away those networks are.

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AC 3 he explanation outlines the principles of network interconnections A gateway, is a that serves as an entrance to another network, and vice- T versa. Gateways are most commonly used to transfer data between private networks and the Internet. A gateway is a network point that acts as an entrance to another network. On the Internet, a node or stopping point can be either a gateway node or a host (end-point) node. Both the computers of Internet users and the computers that serve pages to users are host nodes.

The computers that control traffic within your company's network or at your local Internet service provider (ISP) are gateway nodes. In the network for an enterprise, a computer server acting as a gateway node is often also acting as a proxy server and a firewall server. A gateway is often associated with both a router, which knows where to direct a given packet of data that arrives at the gateway, and a switch, which furnishes the actual path in and out of the gateway for a given packet.

On an IP network, clients should automatically send IP packets with a destination outside a given subnet mask to a network gateway. A subnet mask defines the IP range of a network. For example, if a network has a base IP address of 192.168.0.0 and has a subnet mask of 255.255.255.0, then any data going to an IP address outside of 192.168.0.X will be sent to that network's gateway.

While forwarding an IP packet to another network, the gateway might or might not perform Network Address Translation. A gateway is an essential feature of most routers, although other devices (such as any PC or server) can function as a gateway.

Most computer operating systems use the terms described above. A computer running Microsoft Windows however describes this standard networking feature as Internet Connection Sharing; which will act as a gateway, offering a connection between the Internet and an internal network. Such a system might also act as a DHCP server. Gateway computers: Enable connection from one network, eg: from a LAN to a WAN. Whenever you login to a LAN i.e. connect to the LAN's network server and then access the Internet, you are utilizing a gateway.

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The translation of data into a secret code. Encryption is the most effective way to achieve data security. To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it. Unencrypted data is called plain text; encrypted data is referred to as cipher text. There are two main types of encryption: asymmetric encryption (also called public-key encryption) and symmetric encryption.

AC 4 he explanation outlines and explains network security administration procedures T A cryptographic system that uses two keys -- a public key known to everyone and a private or secret key known only to the recipient of the message. When John wants to send a secure message to Jane, he uses Jane's public key to encrypt the message. Jane then uses her private key to decrypt it.

An important element to the public key system is that the public and private keys are related in such a way that only the public key can be used to encrypt messages and only the corresponding private key can be used to decrypt them. Moreover, it is virtually impossible to deduce the private key if you know the public key.

Public-key systems, such as Pretty Good Privacy (PGP), are becoming popular for transmitting information via the Internet. They are extremely secure and relatively simple to use. The only difficulty with public-key systems is that you need to know the recipient's public key to encrypt a message for him or her. What's needed, therefore, is a global registry of public keys, which is one of the promises of the new LDAP technology.

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AC 5 etwork administration documentation is completed Symmetric Encryption is a type of encryption where the same key is used to N encrypt and decrypt the message. This differs from asymmetric (or public-key) encryption, which uses one key to encrypt a message and another to decrypt the message

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You are now ready to go through a check list. Be honest with yourself Tick the box with either a √ or an X to indicate your response

□ I am able to I am able to explain wide area computer networks (WAN`s).

□ I am able to evaluate a wide area computer network (WAN).

□ I am able to explain Network Administration.

You must think about any point you could not tick. Write this down as a goal. Decide on a plan of action to achieve these goals. Regularly review these goals.

My Goals and Planning: ______

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