Q`.1 Explain Repeater. A repeater is a device that operates only at the PHYSICAL layer. A repeater can be used to increase the length of the network by put the effect on the signal. It connects two segments of the same network. It used for distance limitations of the transmission media. A repeater forwards every frame. it has no filtering capability. A repeater is a regenerator, not an amplifier signal. It remove the noise from signal. Repeaters can connect segments that have the same access method. (CSMA/CD, Token Passing, Polling, etc.) There are two function of them o Right to left Transmission o Left to right Transmission Prepared By: Dhaval R. Patel Page 1
Q.2 Explain Hub with their types. It operate below the physical layer. When there are more than two device is there at that time there are used for connection. A hub is used as a central point of connection among media segments. Cables from network devices plug in to the ports on the hub. Types of HUBS : o A passive hub It is just a connector. It connects the wires coming from different branches. The signal pass through a passive hub without regeneration or amplification. It Connect several networking cables together o Active hubs or Multiport repeaters They regenerate or amplify the signal before they are retransmitted. Prepared By: Dhaval R. Patel Page 2
Q3. Explain Bridges (two layer switch). It Operates in both the Physical and the data link layer. It control the traffic on network. As a PHYSICAL layer device, it regenerates the signal it receives. As a data link layer device, the bridge can check the PHYSICAL/MAC addresses. A bridge has a table for used in filtering decisions. It can check the destination address of a frame and decide if the frame should be forwarded or dropped. If the frame is to be forwarded it send to specified the port. A bridge has a table that maps address to ports. A bridge connecting two LANs. A bridge does not change the physical (MAC) addresses in a frame. Characteristics of Bridges Prepared By: Dhaval R. Patel Page 3
Routing Tables o It Contains one entry per station of network to which bridge is connected. o It Is used to determine the network of destination station of a received packet. Filtering o It Is used by bridge to allow only those packets destined to the remote network. o Packets are filtered with respect to their destination and multicast addresses. Forwarding o the process of passing a packet from one network to another. Learning Algorithm o the process by which the bridge learns how to reach stations on the internetwork. Advantages And Disadvantages Of Bridges Advantages o Extend physical network o Reduce network traffic with minor segmentation o Creates separate collision domain o Reduce collisions o Connect different architecture Disadvantages o Slower that repeaters due to filtering o Do not filter broadcasts o More expensive than repeaters Q.4 Explain Router (three layer switch). It Operates in the Physical, the data link layer and network layer Prepared By: Dhaval R. Patel Page 4
Main function of router it find the shortest path for packages. Routes packets based on their logical addresses (host-to-host addressing) A router normally connects LANs and WANs in the Internet. It has a routing table that is used for making decision about the route. The routing tables are normally dynamic and are updated using routing protocols. Q.5 Explain network gateway. A network gateway is an internetworking system which joining together two networks that use different base protocols. A network gateway can be implemented completely in software or hardware, or as a combination of both. It depending on the types of protocols they support. Network gateways can operate at any level of the OSI model. In firewall gate way is used. In internet router configuration there are gateway is also used. Prepared By: Dhaval R. Patel Page 5
Q.6 Different between Bridge and Router. OR Different between two layer switch and three layer switch. Bridge (Two layer switch) It Operates in both the Physical and the data link layer. It control the traffic on network. Bridge understand MAC addresses A bridge has a table that maps address to ports Router(Three layer switch) It Operates in the Physical, the data link layer and network layer Main function of router it find the shortest path for packages Routers understand IP addresses It has a routing table that is used for making decision about the route. Prepared By: Dhaval R. Patel Page 6