NETWORKING-1-REVIEWER.pdf

NETWORKING 1 REVIEWER Security: Networks implement security measures MODEM modulate and demodulate signals for data such as firewalls, encryption, and access controls to...

NETWORKING 1 REVIEWER Security: Networks implement security measures MODEM modulate and demodulate signals for data such as firewalls, encryption, and access controls to transmission over phone lines, cable systems, or Introduction of Computers protect data and resources. satellite links, enabling internet access. COMPUTER NETWORKING NETWORK FEATURES Types of MODEM: collection of interconnected devices that communicate and Performance: A computer network is measured in DSL (Digital Subscriber Line) Modems: Use share resources with each other- Topologies and its terms of response time. The response time of telephone lines for internet access. definition. sending and receiving data from one node CABLE MODEMS: Use coaxial cables and are Can be defined as a collection of nodes. (computer in a computer network are often referred commonly provided by cable TV companies. as node) to another should be minimal. Understanding the pieces of a network FIBER MODEMS: Use fiber-optic cables for high- Importance of Network Reliability: There should not be any failure in the speed internet access. Communication: Facilitates instant messaging, network or if it occurs the recovery from a failure should be fast. SATELLITE MODEMS: Use satellite connections for emails, video calls, and collaboration tools. remote or rural areas. Security: A computer network should be secure so Resource Sharing: Enables sharing of files, that the data transmitting over a network should be SWITCH Networking devices that connect multiple applications, and hardware resources like printers safe from unauthorized access. devices within a LAN and use MAC addresses to and storage devices. forward data to the correct device. PROPERTIES OF GOOD NETWORK Data Management: Centralizes data storage and Interpersonal Communication: We can ROUTER Devices that connect different networks, management, improving security and accessibility. communicate with each other efficiently and easily. typically a LAN to a WAN like the internet. Efficiency and Productivity: Enhances business Resources can be shared: We can share physical SERVERS & STORAGES used to segment operations by allowing remote access to resources resources by making them available on a network networks for better performance and security, or to and reducing redundancy. such as printers, scanners etc. connect different types of network technologies. Scalability: Supports the growth of businesses by ACCESS POINT (AP OR WAP) Devices that create Sharing files and data: Authorized users are easily expanding network capabilities. a wireless local area network (WLAN), allowing allowed to share the files on the network. Common Uses of Computer Networks: wireless devices to connect to a wired network. Types of Networks and Its definition File Sharing: Networks allow users to share files and Types of Network documents across multiple devices. DEVICES; A network is a group of computers linked to each Internet Access: Networks provide internet NIC are hardware components that connect a other that enables the computer to communicate connectivity to devices, enabling web browsing, computer or other device to a network. with another computer and share their resources, email, and online services. data, and applications. REPEATER regenerate and amplify signals to Application Sharing: Networks support shared extend the distance over which data can travel in a Personal Area Network is a network for applications like database systems, collaboration network. interconnecting devices centered around an tools, and communication platforms. individual person's workspace, typically within a HUB Basic networking devices that connect multiple computers in a LAN. range of a few meters.  Local area network is a network that connects ▪ It defines how various components are connected APPLICATION LAYER computers and other devices within a limited and how data flows between them. ▪ It enables the user to access the network resources. geographical area such as a home, school, office BUS TOPOLOGY consists of a single cable-called a bis- ▪ This layer provides the network services to the end- building, or closely positioned group of buildings. connecting all nodes on a network without intervening users. Metropolitan Area Network – A network that covers connectivity devices. ▪ There are services provided of application layer a larger geographic area by interconnecting a STAR TOPOLOGY design with each node connected ✓ File Transfer Access and Management (FTAM) different LAN to form a larger network. directly to a central network hub or server. ✓ Mail services Wide Area Network is a network that extends over ✓ Directory services RING TOPOLOGY one where all workstations and other a large geographical area such as states or devices are connected in a continuous loop. There is no PRESENTATION LAYER countries. central server. ▪ It is concerned with the syntax and semantics of the Storage Area Network (SAN) – A specialized, TREE TOPOLOGY has a root node and all other nodes information exchange between two systems. dedicated high-speed network that interconnects are connected to it forming hierarchy. It also called ▪ This layer is a part of the operating system that converts and presents shared pools of storage devices to Hierarchical Topology. the data from one presentation format to another format. multiple servers ▪ There are services provided of presentation layer MESH TOPOLOGY a point-to-point connection to other Network Architecture nodes or devices. Mesh has n(n-2)/2 physical channels ✓ Translation – FORMAT CONVERSION - defined as the physical and logical design of the to link hn devices. ✓ Encryption/Decryption – SECURITY OF DATA software, hardware, protocols, and media of the (SSL/TLS / S-MIME /PGP) HYBRID TOPOLOGY is the mixture of two or more transmission of data. Simply we can say that how ✓ Compression – REDUCE DATA AMOUNT topologies. Combines characteristics of linear bus and computers are organized and how tasks are star and/or ring topologies. SESSION LAYER allocated to the computer. ISO Layers ▪ It establishes, maintains and synchronizes the TYPES interaction among communicating devices. Client/ Server network is a network model ▪ There are services provided of session layer designed for the end users called clients, to access ✓ Dialog Control – Half Duplex / Full Duplex the resources such as songs, video, etc. from a ✓ Synchronization – Error Handling / Interruption central computer known as Server. TRANSPORT LAYER Peer-To-Peer network is a network in which all the computers are directly linked together with equal ▪ It is responsible for process to process delivery of the privilege and responsibilities for sharing the data. entire message. ▪ It ensures that messages are transmitted in the order in Network Topology which they are sent and there is no duplication of data. ▪ Network topology refers to the arrangement of ▪ There are services provided of transport layer different elements (links, nodes, server, switch etc.) ✓ Port addressing ( Port Number 0 – 65535 ) in a network. ✓ Segmentation and Reassemble ( Dividing larger data in to smaller segment )  ✓ Connection control ( TCP – Sync – Sync Ack – ✓ Synchronization of bits Acknowledge ) ✓ Line configuration ✓ End to end flow control ( Control the transmission ✓ Physical topology traffic while transferring data. ✓ Error control ( checking of connection on the TCP MODEL SUIT (figure1) network ) ▪ TCP/IP is a hierarchical protocol made up of interactive NETWORK LAYER modules and each of them provides specific ▪ It is responsible for delivery of data from the original functionality. source to the destination network. ▪ It refers to a five-layer protocol suite that defines the ▪ It is a layer 3 that manages device addressing, tracks exchange of transmissions across the Internet the location of devices on the network. ▪ There are services provided of network layer Application ✓ Logical addressing Transport ✓ Routing Internet DATA LINK LAYER Network Access ▪ It is responsible for moving data frames from one node to another node. ▪ It provides a reliable and efficient communication between two or more devices. ▪ There are services provided of data link layer ✓ Framing ✓ Physical addressing ✓ Flow control ✓ Error control ✓ Access control PHYSICAL LAYER ▪ It is responsible for transmitting bits over a medium. It also provides electrical and mechanical specification. ▪ The main functionality of the physical layer is to transmit the individual bits from one node to another node. ▪ There are services provided of physical layer ✓ Physical characteristic of the media ✓ Representation of bits ✓ Data rate  IP ADDRESS An IP address (Internet Protocol address) is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It serves two main functions: 1. Identification: It identifies the host or network interface. 2. Location Addressing: It provides the location of the device in the network, allowing data to be routed correctly. An IP address has 32 bits divided into four octets To make it easier to understand and interprets by the user, It is uses decimal number to represent the binary digits EXAMPLE : 192.168.10.1 An IP address is separated with dotted or period written in binary and decimal format IP TWO VERSIONS IPv4: This is the most common format, consisting of four sets of numbers separated by periods (e.g., 192.168.1.1). Each number can range from 0 to 255. IPv6: This newer format was developed to deal with the limitations of IPv4. It consists of eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334), allowing for a vastly larger number of unique addresses. Figure 1 TCP PROTOCOL SUIT PUBLIC ADDRESS CIDR NOTATION CIDR notation specifies the subnet mask in a more compact form. It indicates the number of bits used Definition: A public IP address is assigned to a 3rd 4th HOST SUBNET MASK for the network portion of the address. device or network that is directly accessible over the Example: In the CIDR notation 192.168.1.0/24, /24 internet. 17 25 128 128 indicates that the first 24 bits are used for the network Characteristics: Unique across the entire internet; portion of the address. allows for communication between devices on 18 26 64 192 NETWORK ADDRESS The address that identifies the different networks globally. subnet itself, with all host bits set to 0. It cannot be assigned Example: Your home router might be assigned a to individual devices. 19 27 32 224 public IP address by your Internet Service Provider Example : For the subnet 192.168.1.0/24, 192.168.1.0 is (ISP), which is visible to the outside world. the network address. 20 28 16 240 PRIVATE ADDRESS BROADCAST ADDRESS The address used to send data to all devices in a subnet, with all host bits set to 1. 21 29 8 248 Definition: A private IP address is used within a Example: For the subnet 192.168.1.0/24, 192.168.1.255 private network (like a home or business network) is the broadcast address. 22 30 4 252 and is not directly accessible from the internet. HOST RANGE (USABLE IP) The range of IP addresses Characteristics: Reserved for use within private that can be assigned to devices within a subnet, excluding 23 31 2 254 networks; devices on the same network can the network and broadcast addresses. communicate with each other using private IP Example : For the subnet 192.168.1.0/24, the host 24 32 1 255 addresses, but these addresses are not unique range is from 192.168.1.1 to 192.168.1.254. across the internet. KEY CONCEPTS IN SUBNETTING Example: Devices within your home network (like SUBNET COMPUTATION your laptop, smartphone, and printer) may use Subnet Mask private IP addresses such as 192.168.1.2 or CIDR Notation SM: (GIVEN) 10.0.0.5. Network Address C (4th octet table / 255……CIDR NOTATION) Host Range ( Usable Address) SUBNETTING is the process of dividing a larger network Broadcast Address B (3rd octet table / 255….CIDR NOTATION.0) into smaller, more manageable sub-networks, known as subnets. This technique improves network performance and SUBNET: 2 # SUBNET BITS ( MGA ONE ) security by limiting the number of devices within each HOST: 2 # HOST BITS ( MGA ZERO ) subnet and by organizing the network more efficiently. UIP: HOST – 2 SUBNET MASK A subnet mask is used to determine which portion of an IP address is the network address and which portion is the host address. Example : Similar to an IP address, it’s expressed in dotted-decimal notation (e.g., 255.255.255.0) or in CIDR (Classless Inter-Domain Routing) notation (e.g., /24).