Computer Networks Basics of Network Devices

Computer Networks Basics of Network Devices

1. Computer Networks Basics of Network Devices A D AD Presented By: C.P.Divate Department of Computer Engineering

2. A D AD Contents Network Devices NIC Repeater HUB Switches Bridge Gateway Routers CSU/ DSU Modem

3. A D AD 1. Network Interface Card NIC Network Interface Card. A hardware component that connects your computer to a local data network or the Internet. A device that takes a signal from a network and converts it to a signal that a computer can understand and T r ansl at es c ompu t er d a t a i nt o electr i c al sign a ls it sends through the network. Provides an interface onto a network (usually a LAN) for a computer system. A NIC is also known as a network interface controller (NIC) , network interface controller card , expansion card , computer circuit board , network card , LAN card , network adapter or network adapter card (NAC).

4. NIC Looks like A D AD

5. A D AD I t ’ s a pl a s tic ci r c ui t b oa r d about the s i z e o f a pl a ying card. It has several computer chips that process signals from the network and the PC. Th e c a r d slid e s i n t o the P C ’ s f r a m e w or k with a connector on the motherboard. A steel bracket holds the card in place. Th e b r ac k e t m a y h a v e a n e t w or k c able jack o r an antenna. The bracket also has light-emitting diodes that indicate network status and activity. Need drivers (software code that helps to run NIC). 1. Network Interface Card NIC

6. A D AD NIC Types Work with Wi-Fi wireless networks: these cards have an antenna to send data signals via radio waves. Wired Ethernet connections: these cables have a rectangular plug which mates with a jack on the network card's bracket. How to install NIC https://www.youtube.com/watch?v=5EwhnXspJmI

7. A D AD 2. Repeater A repeater operates at the physical layer. Its jo b i s t o r e ge n e r a t e t h e s i gna l o v er the sa m e w eak or n e t w or k b e f o r e the signa l b e c o m e s t oo corrupted. It e x t end the l en g th t o which the sig n al c an be transmitted over the same network. An important point to be noted about repeaters is that they do not amplify the signal . Wh e n the signa l b e c o m es w eak, th e y c o p y t h e sign a l bit by bit and regenerate it at the original strength.

8. F u n c ti o n s o f R e pea t e r Corrupted signal Corrupted signal Regenerated signal Left-to Right Transmission Regenerated signal Right- to- Left Transmission Repeater Repeater *

9. * F unc t i on s o f R epea t e r It has no filtering capability It is a regenerator, not an amplifier It does not perform any intelligent function It receives a signal before it becomes too weak or corrupted Regenerates the original bit pattern The repeater forwards the refreshed signal It works in the physical layer

10. Repeater A D AD

11. A D AD 3) H U B Hubs are networking devices operating at a physical layer of the OSI model that are used to connect multiple devices in a network. They are generally used to connect computers in a LAN. A hub has many ports in it. A computer which intends to be connected to the network is plugged in to one of these ports. When a data frame arrives at a port, it is broadcast to every other port, without considering whether it is destined for a particular destination device or not.

12. H U B A D AD

13. A D AD Features of Hubs A hub operates in the physical layer of the OSI model. A hub cannot filter data. It is a non-intelligent network device that sends message to all ports. It primarily broadcasts messages. So, the collision domain of all nodes connected through the hub stays one. Transmission mode is half duplex. Collisions may occurs during setup of transmission when more than one computers place data simultaneously in the corresponding ports. Since they lack intelligence to compute best path for transmission of data packets, inefficiencies and wastage occur. They are passive devices, they don’t have any software associated with it. They generally have fewer ports of 4/12.

14. A D AD Working Layer of Hubs in OSI Model

15. A D AD Types of Hubs

16. Types of HUB LAN HUB USB HUB A D AD BNC HUB Fiber optic SC HUB

17. A D AD 4 . SWICTH It is Hardware device . A high-speed device that receives incoming data packets and redirects them to their destination on a local area network (LAN). A LAN switch operates at the data link layer or the network layer of the OSI Model. A switch has many ports, to which computers are plugged in. A switch, however, keeps a record of the MAC addresses of all the devices connected to it. When a data frame arrives at any port of a network switch, it examines the destination address, performs necessary checks and sends the frame to the corresponding device(s ). It is supports unicast (one-to-one), multicast (one-to-many) and broadcast (one-to-all) communications . Switches also run in full duplex mode .

18. Working of Switch using MAC Address Table

19. Working of Switch using MAC Address Table

20. MAC Address Table at Switch

21. Operating Modes of Switch

22. A D AD 4 . SWICTH Transmission mode is full duplex, i.e. communication in the channel occurs in both the directions at the same time. Due to this, collisions do not occur. Switches are active devices, equipped with network software and network management capabilities. Switches can perform some error checking before forwarding data to the destined port. The number of ports is higher – 24/48

23. A D AD Types of Switches Unmanaged Switch − These are inexpensive switches commonly used in home networks and small businesses . They can be set up by simply plugging in to the network, after which they instantly start operating. When more devices needs to be added, more switches are simply added by this plug and play method. They are referred to as u managed since they do not require to be configured or monitored.

24. A D AD Types of Switches Managed Switch − These are costly switches that are used in organisations with large and complex networks, since they can be customized to augment the functionalities of a standard switch. The augmented features may be QoS (Quality of Service) like higher security levels, better precision control and complete network management. Despite their cost, they are preferred in growing organizations due to their scalability and flexibility. Simple Network Management Protocol (SNMP) is used for configuring managed switches.

25. A D AD Types of Switches LAN Switch − Local Area Network (LAN) switches connects devices in the internal LAN of an organization. They are also referred as Ethernet switches or data switches. These switches are particularly helpful in reducing network congestion or bottlenecks. They allocate bandwidth in a manner so that there is no overlapping of data packets in a network..

26. S W I C T H A D AD

27. A D AD Difference between Switches and HUBs

28. A D AD 5 . BRIDGE Hardware device, works at data link layer. It provides interconnection with other bridge networks that use the same protocol. Connecting two different networks together and providing communication between them. Bridges are similar to repeaters and hubs in that they broadcast data to every node. Bridges maintain the media access control (MAC) address table as soon as they discover new segments, so subsequent transmissions are sent to only to the desired recipient.

29. B R I DG E A D AD

30. A D AD How BRIDGEs Work A bridge uses a database to discover where to pass, transmit or discard the data frame. If the frame received by the bridge is meant for a segment that resides on the same host network, it will pass the frame to that node and the receiving bridge will then discard it. If the bridge receives a frame whose node MAC address is of the connected network, it will forward the frame toward it.

31. How BRIDGEs Work

32. How BRIDGEs Work

33. A D AD 6. Routers Routers are networking devices operating at layer 3 or a network layer of the OSI model. They are responsible for receiving, analysing , and forwarding data packets among the connected computer networks. When a data packet arrives, the router inspects the destination address, consults its routing tables to decide the optimal route and then transfers the packet along this route . A router is a device like a switch that routes data packets based on their IP addresses. Routers normally connect LANs and WANs together or a LAN and its ISP's network –for example, your PC and your service provider. Have a dynamically updating routing table based on which they make decisions on routing the data packets.

34. A D AD 6. Routers

35. A D AD 6. Routers

36. A D AD Features of Routers A router is a layer 3 or network layer device. It connects different networks together and sends data packets from one network to another. A router can be used both in LANs (Local Area Networks) and WANs (Wide Area Networks ). It transfers data in the form of IP packets. In order to transmit data, it uses IP address mentioned in the destination field of the IP packet. Routers have a routing table in it that is refreshed periodically according to the changes in the network. In order to transmit data packets, it consults the table and uses a routing protocol. In order to prepare or refresh the routing table, routers share information among each other. Routers provide protection against broadcast storms. Routers are more expensive than other networking devices like hubs , bridges and switches .

37. A D AD Features of Routers Routers are manufactured by some popular companies like −. Cisco D-Link HP 3Com Juniper Nortel

38. A D AD R o u t e r s Routers are located at gateways, the places where two or more networks connect. Routers use packet headers and forwarding tables to determine the best path for forwarding the packets. And they use protocols to communicate with each other and configure the best route between any two hosts.

39. A D AD Routing Table The functioning of a router depends largely upon the routing table stored in it. The routing table stores the available routes for all destinations. The router consults the routing table to determine the optimal route through which the data packets can be sent. A routing table typically contains the following entities − IP addresses and subnet mask of the nodes in the network IP addresses of the routers in the network Interface information among the network devices and channels Routing tables are of two types − Static Routing Table − Here, the routes are fed manually and are not refreshed automatically. It is suitable for small networks containing 2-3 routers. Dynamic Routing Table − Here, the router communicates with other routers using routing protocols to determine the available routes. It is suited for larger networks having large number of routers.

40. A D AD Types of Routers Wireless Router − They provide WiFi connection WiFi devices like laptops, smartphones etc. They can also provide standard Ethernet routing. For indoor connections, the range is 150 feet while its 300 feet for outdoor connections. Broadband Routers − They are used to connect to the Internet through telephone and to use voice over Internet Protocol (VoIP) technology for providing high-speed Internet access. They are configured and provided by the Internet Service Provider (ISP).

41. R o u t e r A D AD Wireless Router Wired Router

42. A D AD 7 . Gateways A gateway is a network node that forms a passage between two networks operating with different transmission protocols . A gateway, as the name suggests, is a passage to connect two networks together that may work upon different networking models. The most common type of gateways, the network gateway operates at layer 3, i.e. network layer of the OSI (open systems interconnection) model. However , depending upon the functionality, a gateway can operate at any of the seven layers of OSI model. It acts as the entry – exit point for a network since all traffic that flows across the networks should pass through the gateway. Only the internal traffic between the nodes of a LAN does not pass through the gateway. .

43. Working of Gateways

44. Gate Way

45. A D AD 7. Gateway They basically works as the messenger agents that take data from one system, interpret it, and transfer it to another system. Gateways are also called protocol converters and can operate at any network layer. Gateways are generally more complex than switch or router.

46. G a t e w a y A D AD

47. A D AD Features of Gateways Gateway is located at the boundary of a network and manages all data that inflows or outflows from that network. It forms a passage between two different networks operating with different transmission protocols. A gateway operates as a protocol converter, providing compatibility between the different protocols used in the two different networks. The feature that differentiates a gateway from other network devices is that it can operate at any layer of the OSI model. It also stores information about the routing paths of the communicating networks. When used in enterprise scenario, a gateway node may be supplemented as proxy server or firewall. A gateway is generally implemented as a node with multiple NICs (network interface cards) connected to different networks. However, it can also be configured using software. It uses packet switching technique to transmit data across the networks.

48. A D AD Types of Gateways Unidirectional Gateways − They allow data to flow in only one direction. Changes made in the source node are replicated in the destination node, but not vice versa. They can be used as archiving tools. . Bidirectional Gateways − They allow data to flow in both directions. They can be used as synchronization tools. On basis of direction of data flow, gateways are broadly divided into two categories −

49. A D AD Types of Gateways Network Gateway − This is the most common type of gateway that provides as interface between two dissimilar networks operating with different protocols. Whenever the term gateway is mentioned without specifying the type, it indicates a network gateway. . Cloud Storage Gateway − It is a network node or server that translates storage requests with different cloud storage service API calls, such as SOAP (Simple Object Access Protocol) or REST ( REpresentational State Transfer).It facilitates integration of private cloud storage into applications without necessitating transfer of the applications into any public cloud, thus simplifying data communication. . On basis of functionalities, there can be a variety of gateways, the prominent among them are as follows −

50. Working Layers Of Networking Devices

51. Devices Symbols A D AD

52. A D AD 8 . MODEM Modem is short for Modulator / Demodulator . It is a hardware component that allows a computer or other device, such as a router or switch, to connect to the Internet. It converts or modulates an analog signal from a telephone or cable wire to a digital signal that a computer can recognize. Similarly, it converts outgoing digital data from a computer or other device to an analog signal.

53. M O D E M A D AD

54. A D AD M O D E M The first modems were dial-up meaning they had to dial a phone number to connect to an ISP . These modems operated over standard analog phone lines and used the same frequencies as telephone calls, which limited their maximum data transfer rate to 56 Kbps. Dial-up modems also required full use of the local telephone line, meaning voice calls would interrupt the Internet connection.

55. A D AD M O D E M M o dern modems a r e ty p i c al l y DS L or c able modems, which are considered broadband devices. DSL modems operate over standard telephone lines, but use a wider frequency range. This allows for higher data transfer rates than dial- up modems and enables them to not interfere with phone calls.

56. A D AD Thank You!