Local Area Network (LAN) Metropolitan Area Network (MAN) Wide Area Network (WAN) Global Area Network (GAN) Network Classifications 02 INTRODUCTION TO NETWORKING Understand Network Classifications 2.3
LANs have higher data rates (10Mbps to 40Gbps) as compared to WANs. A LAN consists of : Shared transmission medium now so valid today due to switched LANs Regulations for orderly access to the medium Set of hardware and software for the interfacing devices A local area network (LAN) is a data communication system that allows a number of independent devices to communicate directly with each other in a limited geographic area such as a single department, a single building, or a campus. A large organization may need several connected LANs. The most popular LANs are Ethernet and wireless LANs. 02 INTRODUCTION TO NETWORKING Local Area Network (LAN) Transmission Medium Network Interface Card (NIC) Unique MAC “physical” address Figure 2-5 Local Area Network (LAN)
A Wide Area Network is a network that covers a broad area (i.e., any telecommunications network that links across metropolitan, regional, or national boundaries) using private or public network transports. Business and government entities utilize WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations. Wide Area Network(WAN) 02 INTRODUCTION TO NETWORKING Figure 2-6 Wide Area Network(WAN)
02 INTRODUCTION TO NETWORKING Metropolitan Area Network (MAN) A MAN is optimized for a larger geographical area than a LAN, ranging from several blocks of buildings to entire cities. MANs can also depend on communications channels of moderate-to-high data rates. A MAN might be owned and operated by a single organization, but it usually will be used by many individuals and organizations. MANs might also be owned and operated as public utilities. They will often provide means for internetworking of local networks. Figure 2-7 Metropolitan Area Network (MAN)
Figure 2-8 Global Area Network (GAN) 02 INTRODUCTION TO NETWORKING Global Area Network (GAN) A global area network (GAN) refers to a network composed of different interconnected networks that cover an unlimited geographical area. The term is loosely synonymous with Internet, which is considered a global area network.
02 INTRODUCTION TO NETWORKING Figure 2-9 Network Classifications Diagrams NETWORK CLASSIFICATIONS Global Area Network
02 INTRODUCTION TO NETWORKING WIRING STANDARD IN NETWORKING 2.4 T568 A and T568 B T568A and T568B are the two wiring standards for an 8-position modular connector T568B is commonly used in commercial installations, while T568A is prevalent in residential installations The only difference between T568A and T568B is that the orange and green wire pairs (pairs two and three) are interchanged
02 INTRODUCTION TO NETWORKING WIRING STANDARD IN NETWORKING 2.4 Figure 2-10 T568A and T568B Take a look at the color of wiring!! It's diffrent!
Straight-Through Wired Cables Straight-Through refers to cables that have the pin assignments on each end of the cable. In other words Pin 1 connector A goes to Pin 1 on connector B, Pin 2 to Pin 2 ect. Straight-Through wired cables are most commonly used to connect a host to client. The Straight-Through wired cable is used to connect computers, printers and other network client devices to the router switch or hub. 02 INTRODUCTION TO NETWORKING Figure 2-11 Straight-Through Wired Cables NETWORK CABLING 2.5
Crossover Wired Cables 02 INTRODUCTION TO NETWORKING Crossover wired cables (commonly called crossover cables) are very much like Straight-Through cables with the exception that TX and RX lines are crossed. Using the 568-B standard as an example below you will see that Pin 1 on connector A goes to Pin 3 on connector B. Pin 2 on connector A goes to Pin 6 on connector B ect. Crossover cables are most commonly used to connect two hosts directly. Examples would be connecting a computer directly to another computer, connecting a switch directly to another switch, or connecting a router to a router. Figure 2-12 Crossover Wired Cables
Network security is a set of rules and configurations designed to protect the integrity, confidentiality and accessibility of computer networks and data using both software and hardware technologies. There are many layers to consider when addressing network security across an organization. Attacks can happen at any layer in the network security layers model, so your network security hardware, software and policies must be designed to address each area. 02 INTRODUCTION TO NETWORKING NETWORK SECURITY 2.6 TYPE OF NETWORK SECURITY Email Security Packet Filter Web Security Firewall Antivirus & Antimalware Software Network Access Control Figure 2-13 Type of Network Security
Antivirus and antimalware software protect an organization from a range of malicious software, including viruses, ransomware, worms and trojans. The best software not only scans files upon entry to the network but continuously scans and tracks files. 02 INTRODUCTION TO NETWORKING TYPE OF NETWORK SECURITY ~Network Access Control~ To ensure that potential attackers cannot infiltrate your network, comprehensive access control policies need to be in place for both users and devices. Network access control (NAC) can be set at the most granular level. For example, you could grant administrators full access to the network but deny access to specific confidential folders or prevent their personal devices from joining the network. ~Antivirus and Antimalware Software ~ ~Firewall~ Firewalls, as their name suggests, act as a barrier between the untrusted external networks and your trusted internal network. Administrators typically configure a set of defined rules that blocks or permits traffic onto the network. For example, Forcepoint's Next Generation Firewall (NGFW) offers seamless and centrally managed control of network traffic, whether it is physical, virtual or in the cloud.
02 INTRODUCTION TO NETWORKING TYPE OF NETWORK SECURITY ~Web Security~ Web security is also known as “Cybersecurity”. It basically means protecting a website or web application by detecting, preventing and responding to cyber threats. Websites and web applications are just as prone to security breaches as physical homes, stores, and government locations. Unfortunately, cybercrime happens every day, and great web security measures are needed to protect websites and web applications from becoming compromised. Anything that is applied over the Internet should have some form of web security to protect it. ~Packet Filter~ Packet filtering is a firewall technique used to control network access by monitoring outgoing and incoming packets and allowing them to pass or halt based on the source and destination Internet Protocol (IP) addresses, protocols and ports. Packet filtering checks source and destination IP addresses. If both IP addresses match, the packet is considered secure and verified. Because the sender may use different applications and programs, packet filtering also checks source and destination protocols, such as User Datagram Protocol (UDP) and Transmission Control Protocol (TCP). Packet filters also verify source and destination port addresses.
Email security is the term for any procedure that protects email content and accounts against unauthorized access. Email service providers have email security measures in place to secure client accounts and information from hackers. Such measures include email servers with strong password and access control mechanisms; encrypted email messages (both inboxed or in transit); web application firewalls; and spam filtering software. Email is popular with hackers as a tool for spreading malware, spam, and phishing attacks. Email is also a main entry point for attackers looking to access an enterprise network and breach valuable company data. 02 INTRODUCTION TO NETWORKING TYPE OF NETWORK SECURITY ~Email Security~
03 THE OPEN SYSTEMS INTERCONNECTION (OSI MODEL AND NETWORK PROTOCOL) 03
THE OPEN SYSTEMSINTERCONNECTION (OSI MODEL AND NETWORK PROTOCOL) 03 3.1 Remember Open Systems Interconnection (OSI) Model 3.2 Remember Network Protocol 3.3 Understand the TCP/IP protocol suite 3.4 Apply the understanding of TCP/IP protocol suite 3.5 Investigate addressing scheme for TCP/IP protocol suite 3.6 Understand Basic IP Routing (Layer 3) 3.7 Understand types of network services CONTENTS
The Open Systems Interconnection model is a layered framework for the design of network systems that allows for communication across all types of computer systems. It consists of seven separate but related layers, each of which defines a segment of the process of moving information across a network. 03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK Define OSI Model
03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK Identify the function of OSI Model Figure 3-1 OSI Model
03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK Remember Network Protocol Figure 3-2 Network Protocol
03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK TCP/IP Model TCP/IP Reference Model is a four-layered suite of communication protocols. It was developed by the DoD (Department of Defence) in the 1960s. It is named after the two main protocols that are used in the model, namely, TCP and IP. TCP stands for Transmission Control Protocol and IP stands for Internet Protocol. Figure 3-3 TCP/IP Layer
Host-to- Network Layer −It is the lowest layer that is concerned with the physical transmission of data. TCP/IP does not specifically define any protocol here but supports all the standard protocols. Internet Layer −It defines the protocols for logical transmission of data over the network. The main protocol in this layer is Internet Protocol (IP) and it is supported by the protocols ICMP, IGMP, RARP, and ARP. Transport Layer − It is responsible for error-free end-to-end delivery of data. The protocols defined here are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). Application Layer − This is the topmost layer and defines the interface of host programs with the transport layer services. This layer includes all high-level protocols like Telnet, DNS, HTTP, FTP, SMTP, etc. The four layers in the TCP/IP protocol suite are − 03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK Function of TCP/IP Layer
03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK Protocol of TCP/IP Layer Figure 3-4_A Protocol TCP/IP with protocol
03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK Protocol of TCP/IP Layer Figure 3-4_B Protocol TCP/IP with protocol
03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK Show the relation of TCP/IP to OSI Model Layer Figure 3-5 TCP/IP with OSI Model and Protocol
03 THE OPEN SYSTEM INTERCONNECTION (OSI MODEL AND NETWORK Addressing scheme for TCP/IP suite Figure 3- 5 TCP/IP with addressing scheme
04 LOCAL AREA NETWORK 04
LOCAL AREA NETWORK 04 CONTENTS 4.1 Remember Local Area Network 4.2 Apply the knowledge of Media Access Control (MAC) 4.3 Understand IEEE Standard Project 802 4.4 Remember Standard Ethernet 4.5 Apply Wireless LAN 4.6 Investigate the services of wireless LAN 4.7 Investigate the configuration of Wireless LAN
Definition 04 LOCAL AREA NETWORK A local area network (LAN) is a data communication system that allows a number of independent devices to communicate directly with each other in a limited geographic area such as a single department, a single building, or a campus Definition of Local Area Network 4.1. Figure 4-1_A Components of a Local Area Network
Definition Ethernet is the technology that is commonly used in wired local area networks (LANs). A LAN is a network of computers and other electronic devices that covers a small area such as a room, office, or building 04 LOCAL AREA NETWORK Ethernet Local Area Network Figure 4-1_B Ethernet Local Area Network
Definition 04 LOCAL AREA NETWORK Identify the four generation of Ethernet LAN 4.1.2 Figure 4-2_B Generation of Ethernet Figure 4-.2_A Generation of Ethernet
A MAC (Media Access Control) protocol is a set of rules to control access to a shared communication medium among various users. ● Medium Access Control (MAC) is a sub layer of the Datalink layer. The protocols used to determine who goes next on a multi access channel belongs to a MAC sub layer Carrier sense Multiple access/Collision Avoidance 04 LOCAL AREA NETWORK Media Acces Control (MAC) 4.2 1 2 3 Carrier Sense Multiple Access /Collision Detection Token Passing
04 LOCAL AREA NETWORK MEDIA ACCES CONTROL (MAC) CARRIER SENSE MULTIPLE ACCESS Figure 4-3 CSMA/CD
The basic idea is for the sender to stimulate the Sender sends an RTS (Request To Send) frame. Receiver replies with a CTS (Clear To Send) frame. An ACK frame is sent after each successful data frame receiver into outputting a short frame, so stations nearby can detect this transmission and avoid transmitting themselves for the upcoming large data frame. 04 LOCAL AREA NETWORK 3 CARRIER SENSE MULTIPLE ACCESS /COLLISION AVOIDANCE
IEEE 802.11 standard for WLAN defines a distributedcoordination function (DCF) for sharing access to themedium based on the CSMA/CA protocolCollision detection is not used since a node is unable todetect the channel and transmit data simultaneously. A node listens to the channel before transmission todetermine whether some one else is transmittingThe receiving node sends an acknowledge packet(ACK) a short time interval after receiving the packetIf an ACK is not received, the packet is considered lost and a retransmission is arranged 04 LOCAL AREA NETWORK 3 Carrier Sense Multiple Access /Collision Avoidance
04 LOCAL AREA NETWORK Carrier Sense Multiple Access /Collision Avoidance 4.2.1 Figure 4.4 (A)-(B) CSMA with avoidance Figure 4.4 CSMA with avoidance (A) (B)
Two stations may check the data simultaneously Both may find the line free and engage in the transmission of data. Both transmission will collide CD component will detect this collision Inform the workstations of the collision. Each station will wait for a random period of time before attempting to transmit again 04 LOCAL AREA NETWORK Carrier Sense Multiple Access /Collision Detection
The Token Ring technique is based on the use of a small frame called a token, that circulates when all stations are idle. Whenever a station wishes to send a frame it waits until it receives the token. As it seizes the token one bit is changed which then transforms the token into a start of frame sequence for a data frame 04 LOCAL AREA NETWORK TOKEN PASSING
The station then transmits the reminder of the data fields necessary to complete a data frame. The data frame includes the destination station address at its head. The frame is repeated (received, checked and retransmitted), by each station on the network until it circulates back to the source station, where it is removed. In addition to repeating the frame, the destination station retains a copy of the frame and this is indicated by the setting of the response bits, at the end of the frame 04 LOCAL AREA NETWORK Token Passing
The manner in which stations release the token after transmitting data depends on the ring data rate. With rings which operate at the conventional 4 Mbps, the token is released only after the transmitted frames response bits have been received back at the transmitting station. With modern rings which operate at the higher rate of 16 Mbps., the token is released after transmitting the last bit of the frame.This is known as Early Token Release (ETR) 04 LOCAL AREA NETWORK Token Passing
A token is a small message that circulates among the stations of a computer network providing permission to the stations for transmission. If a station has a frame to transmit when it receives a token, it sends the frame and then passes the token to the next station; otherwise it simply passes the token to the next station. 04 LOCAL AREA NETWORK Token Passing Figure 4-5 Token Passing operation
Current LANs are most likely to be based on Ethernet protocols developed by IEEE 802 committee. IEEE is acronym for Institution of Electrical and Electronic Engineering. It is a professional non-profit organization IEEE 802 refers to a family of IEEE standards which; Dealing with local area network and metropolitan area network. Restricted to networks carrying variable-size packets. Standard mostly applies to the lower two layers; Data link layer Physical layer 04 LOCAL AREA NETWORK LAN Standard -IEEE 802
04 LOCAL AREA NETWORK IEEE 802 Protocol Layers VS OSI Model As with all IEEE 802 protocols, the data link layer is divided into two IEEE 802 sublayers: the Media Access Control (MAC) sublayer and the MAC-client sublayer (logical-link control or bridge). The IEEE 802.3 physical layer corresponds to the OSI model physical layer (Layer 1). Figure 4-6 OSI Model with IEEE protocol
Logical Link Control (LLC) handles Framing – in both LLC and MAC flow control, error control. The LLC layer is concerned with managing traffic (flow and error control) over the physical medium. 04 LOCAL AREA NETWORK LLC Logical Link Control
MAC Media Acess Control Frame Format 04 LOCAL AREA NETWORK The general MAC frame format consists of a header, framebody, and frame check sequence (FCS). The header holds information about the frame. The frame-body carries data that needs to be transmitted. The transmitter calculates the FCS over the header and frame-body. Figure 4-7 MAC Frame format
One of the IEEE 802 standards - the IEEE 802.3 is known as “Ethernet,” the most prevalently used LAN technology around the globe. Defined as the 802.3 standard by the IEEE, the Ethernet access method is used to connect computers in a company or home network as well as to connect a single computer to a modem for Internet access. Data rate is 10Mbps Topology: Branching non-rooted tree Ethernet was designed by the Xerox Corporation in 1972 Ethernet port transmits 10 and 100 Mbps, while the maximum speed of a 10/100/1000 "Gigabit" port is 1 Gbps. 04 LOCAL AREA NETWORK WHAT IS ETHERNET
04 LOCAL AREA NETWORK Figure 4-8 Ethernet Diagram Figure 4-9 Connection in Ethernet LAN WHAT IS ETHERNET
•Specified in the family of standards known as IEEE 802.3. • Ethernet was initially designed to run over coaxial cables. • a typical Ethernet LAN now uses special grades of twisted pair cables, or fiber optical cabling. Wi-Fi standards. •Ethernet standards are steadily evolving to embrace new media, higher transmission speeds and changes in frame content 04 LOCAL AREA NETWORK "Media Access Control" (MAC)
A wireless local area network (WLAN) is a wireless computer network that links two or more devices using a wireless distribution method (often spread-spectrum or OFDM radio) within a limited area such as a home, school, computer laboratory, or office building. This gives users the ability to move around within a local coverage area and yet still be connected to the network. A WLAN can also provide a connection to the wider Internet. A cellular network is an example of WLAN 04 LOCAL AREA NETWORK What is Wireless LAN ??
04 LOCAL AREA NETWORK WIRELESS LAN ?? Figure 4.-10 Component in WLAN
Access Point (AC) Adapter Card Directional antenna Extension Point (EP) Wired Network 04 LOCAL AREA NETWORK BASIC HARDWARE OF WIRELESS LAN