Network Foundations PDF

Network Foundations Prepared by: Pr. RIAHLA 1  Program Our program is as follows:  Overview of Computer Networks  Open Systems Interconnection (OSI) Reference model  TCP/IP model  Networks: Advanced Concepts Prepared by: Pr. RIAHLA...

Network Foundations Prepared by: Pr. RIAHLA 1  Program Our program is as follows:  Overview of Computer Networks  Open Systems Interconnection (OSI) Reference model  TCP/IP model  Networks: Advanced Concepts Prepared by: Pr. RIAHLA 2  Program: Practical Work Configuration VLAN Configuration We will focus on practical works Prepared by: Pr. RIAHLA 3 Overview of Computer Networks 4 Why connect electronic devices? Today, everyone is interconnected. 5 And, every things.  Why connect electronic devices? Networks are used in many different areas today. For example, in: Industry, Military, Medical, Chemical, etc. Enterprise (Administration), Internet (the network of networks) Prepared by: Pr. RIAHLA 6  Industry, Military, Medical, Chemical, etc. Military Rescue Extended Wi-Fi Prepared by: Pr. RIAHLA 7  Industry, Military, Medical, Chemical, etc. Military Tracking Medical Monitoring Wildfires detection Volcano Monitoring Prepared by: Pr. RIAHLA 8  Entreprise (administration)  Resource Sharing Sharing and Transferring Resources: Files, Folders, Printers, etc. Sharing Applications: Compiler, Database Management System (DBMS). Sharing Computing Power  High Reliability  The duration during which the infrastructure operates without interruption  Cost Reduction Prepared by: Pr. RIAHLA 9  Internet (The network of networks) 10  Internet (le réseau des réseaux) 11 Réalisé par : Dr RIAHLA 1  Communication Networks: Graph Node Arc/ links A computer network is a graph composed of nodes and arcs Prepared by: Pr. RIAHLA 12  Communication Networks: Graph Node Arc Arc: Communication Support: Network Cable, Wi-Fi, Fiber Optics, Satellite, etc. Node: Can be: : Communication Equipment: PC, Smartphone, Sensor, Chip, Robot Arm, etc. or Interconnection Equipment: Repeater, Hub, Switch, Router, Firewall, Wi-Fi Access Point, Application Gateway, etc. Prepared by: Pr. RIAHLA 13  Network Classification We can have Two Classifications: by Size by Topology Exemple : Exemple: PAN, LAN, MAN, BUS, anneau, etoile,.. WAN,… Prepared by: Pr. RIAHLA 14  Network Classification Two Classifications: by Size by Topology Exemple : Exemple: PAN, LAN, MAN, BUS, anneau, etoile,.. WAN,… Prepared by: Pr. RIAHLA 15  Classifications, by Size PAN LAN MAN WAN 1M 10M 100M 1KM 10KM 100KM Prepared by: Pr. RIAHLA 16  Classifications, by Size PAN Very small: covers a range of a few meters 1M 10M 100M 1KM 10KM 100KM Prepared by: Pr. RIAHLA 17  Classifications, by Size Covers a small area, LAN Such as a single building or office, Typically within a few hundred meters 1M 10M 100M 1KM 10KM 100KM Prepared by: Pr. RIAHLA 18  Classifications, by Size Exp: WMAN: WiMAX Connecting Multiple LANs MAN in Geographic Proximity: 1M 10M 100M 1KM 10KM 100KM Spans a city or a large campus, Typically within a few kilometers. Sidi Abdallah Technolog y Park Prepared by: Pr. RIAHLA 19  Classifications, by Size WAN 1M 10M 100M 1KM 10KM 100KM Covers a broad geographic area, Ranging from cities to entire countries Even continents Prepared by: Pr. RIAHLA 20  Classifications, by Size GAN??? GANs use the fiber optic infrastructures of Wide Area Networks (WANs) and combine them with international submarine cables or satellite transmissions 21  Network Classification Two Classifications: by Size by Topology Exemple : Exemple: LAN, MAN, WAN,… BUS, anneau, etoile,.. Prepared by: Pr. RIAHLA 22  Classifications, by Topology To enable communication between two workstations, the two machines must be connected in a specific manner and use a common communication language.  Common communication language: protocole.  Specific manner: That's what we call topology.. Prepared by: Pr. RIAHLA 23  What does 'protocol' mean? A set of rules that govern the communication between network devices. It defines how data is transmitted, formatted, and processed over a network, Ensuring that devices can effectively communicate and understand each other. Prepared by: Pr. RIAHLA 24  Classifications, by Topology Topology is the arrangement of elements in a network Two Classifications: Point-to-point Broadcast Mode Mode Prepared by: Pr. RIAHLA 25  Classifications, by Topology Broadcast Mode Bus topology Satellite topology Token ring topology The communication medium is shared. A Single Broadcast Domain Prepared by: Pr. RIAHLA 26  Classifications, by Topology Broadcast Mode Only one device sends data at any given time. If two devices transmit at the same time, a collision happens, resulting in the loss of the messages. When a device sends a message, everyone receives it, even if they are not the intended recipients! Prepared by: Pr. RIAHLA 27  Classifications, by Topology Broadcast Mode: The traditional bus Bus topology connects all devices to a single central cable for data transmission, When a device sends data, it travels along the bus Prepared by: Pr. RIAHLA 28  Classifications, by Topology Broadcast Mode: Token ring A device can only send data if it possesses the token Prepared by: Pr. RIAHLA 29  Classifications, by Topology Broadcast Mode: Wi-FI Electromagnetic waves Prepared by: Pr. RIAHLA 30  Classifications, by Topology Two Classifications: Broadcast Point-to-point Mode Mode Prepared by: Pr. RIAHLA 31  Classifications, by Topology Point-to-point Mode Star Topology full mesh topology partial mesh topology The communication medium is not shared Prepared by: Pr. RIAHLA 32  Classifications, by Topology Point-to-point Mode: star topology Star topology connects all devices to a central hub or switch Prepared by: Pr. RIAHLA 33  Classifications, by Topology Point-to-point Mode Tree Topology: A hierarchical structure that combines characteristics of star and bus topologies, with groups of star- configured networks connected to a linear bus backbone. Hybrid Topology: A combination of two or more different topologies, leveraging the advantages of each to create a more robust and scalable network Prepared by: Pr. RIAHLA 34  Connection modes Two Connection modes Connection-less connection- mode oriented mode Prepared by: Pr. RIAHLA 35  Connection-oriented mode The two communicating devices must be present  The sender requests the establishment of a connection with a host.  If the receiver rejects the connection, it will not be established.  Otherwise, a link is established between the sender and the receiver.  Data is transmitted from one point to another with ACK.  Finally, the communication is terminated. Prepared by: Pr. RIAHLA 36  Connection-oriented mode: Example Telephone communication Prepared by: Pr. RIAHLA 37  Connection-less mode The presence of both parties is not required  The sender transmits a message with the recipient's address over a medium, expecting it to be delivered  The transmission happens without checking if the information is received (without ACK: acknowledgment) Less reliable than the connection- oriented mode, but faster Prepared by: Pr. RIAHLA 38  Connection-less mode Example: Postal mail Prepared by: Pr. RIAHLA 39  Connection strategy Whether connected or not, communications are based on a switching principle It creates temporary circuits to send a message from one node to another Switching includes methods that connect two subscribers vPrepared by: Pr. RIAHLA 40  Connection strategy Circuit switching Message switching Packet switching Cell switching Réalisé par : Dr RIAHLA 41  Connection strategy: Circuit switching A communication line (circuit) between a sender node and a receiver node is reserved for the duration of the communication to allow data transfer The circuit is released at the end of the transmission Virtual circuit Prepared by: Pr. RIAHLA 42  Connection strategy: Message switching Transmit the message sequentially from one node to another Each node waits to receive the full message before sending it to the next Switch 1 Switch 2 Switch 3 Switch 4 Switch 5 Prepared by: Pr. RIAHLA 43  Connection strategy: Packet switching Packet switching involves segmenting (divided) information into data packets, which are transmitted independently by intermediate nodes and reassembled at the destination Prepared by: Pr. RIAHLA 44  Connection strategy: Cell switching Cell switching is a specific type of packet switching where all packets have a fixed length of 53 bytes. Cell switching combines packet switching and circuit switching Example: ATM, commonly used for multiplexing in DSL networks Prepared by: Pr. RIAHLA 45  Network architectures We will study three architectures  Peer-to-peer (P2P),  Client/server  Three-tier. Prepared by: Pr. RIAHLA 46  Peer-to-peer (P2P) architecture P2P architecture is a decentralized model where each participant can act as both a client and a server, sharing resources directly with others Prepared by: Pr. RIAHLA 47  Peer-to-peer (P2P) architecture Advantage: Robustness Disadvantages: Security and administration are very challenging Prepared by: Pr. RIAHLA 48  Client/server architecture Client-server architecture is a model where clients ask for services from central servers, which provide the responses Prepared by: Pr. RIAHLA 49  Client/server architecture The mistake to avoid Server of what? Prepared by: Pr. RIAHLA 50  Client/server architecture The mistake to avoid WEB Server Files Server Mail Server Database Server HTTP FTP SMTP SGBD Prepared by: Pr. RIAHLA 51  Client/server architecture Advantages: Security, Centralization Disadvantages The server is the weak point of this architecture The server is always overloaded (busy) This architecture requires client software installation Prepared by: Pr. RIAHLA 52  Three-tier architecture LEVEL 1 LEVEL 2 Sending SQL query requests LEVEL 3 Sending responses Thin Client Application Database Server Server: Storage Calculation Server Prepared by: Pr. RIAHLA 53  Three-tier architecture LEVEL 1 LEVEL 2 LEVEL 3 Thin client Calculation Server Storage Server Prepared by: Pr. RIAHLA 54  Three-tier architecture HTTP SQL Prepared by: Pr. RIAHLA 55  Three-tier architecture Advantages: Thin clients need no installation the server is less loaded Prepared by: Pr. RIAHLA 56  Summary Why connect electronic devices? What is a network? Network size: PAN, LAN, MAN, WAN, GAN Topology  broadcast: bus, token ring, satellite, wifi,…  Point-to-point: star , mesh,… Connection Mode : connection-oriented, connection-less Connection strategy: Circuit switching, message switching, packet switching, cell switching Architectures : P2P, client/server, 3 tier. Prepared by: Pr. RIAHLA 57  Overview Network Physical Logical Hardware (network : Architecture (P2P, card, cabling, switch,...) client/server,3 tier) Topology(bus, token Modes, stratégy,… ring, star,…)  Protocoles Prepared by: Pr. RIAHLA 58  Problem!!! Each manufacturer has developed its own network solution and communication protocols IBM SNA DEC DECNET NOVELL Netware IPX/SPX Microsoft NETBIOS Apple APPLE TALK VAX VMS Proprietary networks Prepared by: Pr. RIAHLA 59  Proprietary networks Prepared by: Pr. RIAHLA 60  OSI Model Application layer Application Presentation layer management Session Layer Transport Layer Network layer Transport Link state Layer function Physical layer Prepared by: Pr. RIAHLA 61