Machine 1 wants to send some data to machine 4, so it first has to capture the free Token. It then writes its data and the recipient's address onto the Token (represented by the yellow flashing screen). The packet of data is then sent to machine 2 who reads the address, realizes it is not its own, so passes it on to machine 3. Machine 3 does the same and passes the Token on to machine 4. This time it is the correct address and so number 4 reads the message (represented by the yellow flashing screen). It cannot, however, release a Token on to the ring, it must first send the message back to number 1 with an acknowledgement to say that it has received the data (represented by the purple flashing screen). The receipt is then sent to machine 5 who checks the address, realizes that it is not its own and so forwards it on to the next machine in the ring, number 6. Machine 6 does the same and forwards the data to number 1, who sent the original message. Machine 1 recognizes the address, reads the acknowledgement from number 4 (represented by the purple flashing screen) and then releases the free Token back on to the ring ready for the next machine to use.
3.1.1 network topology complete
3.0 Internet Technology 3.1 3.2 3.3 3.5 Network The Internet Internet Netiquette Basic Services 3.2.1 3.2.2 Overview the World Wide Web 3.1.1 internetNetwork Topology 188.8.131.52 184.108.40.206 Web Browser 3.4 3.1.2 Evolution of the Types of Classification of internet 220.127.116.11 network Web page Websites 18.104.22.168 navigation The internet connection 22.214.171.124 Information 126.96.36.199 searching Internet Service Provider 188.8.131.52 The Internet Address
LEARNING OUTCOMESAt the end of this topic, students shouldbe able to:1) Explain types of network topology
What Is a Network? A network is a collection of computers and devices connectedtogether via communications devices and transmission media Shelly Cashman
What Is a Network Topology?A network topology refers to the layout of the computers and devices in a communications network. Shelly Cashman
Diagram of different network topologies. StarRing Bus
It refers to both the physical and logicallayout of a network.
Types of network topology.Three commonly used network topologies are:
Bus Network Topology A bus network consists of a single central cable (backbone), to which all computers and other nodes connect. Backbone
Bus Network TopologyThe bus is the physical cable that connects the computersand other nodes. The bus in a bus network transmit data, instructions, andinformation as a series of signal. Those signals are sent as electrical pulses that travel along thelength of the cable in all directions.
Bus Network Topology Each nodes is connected to the single bus T-Connector cable through T-Connector. A terminator is required at each end of the bus cable to prevent the signal from bouncing back and forth on the bus cable.
Bus Network Topology When a sending device transmits data, the address of thereceiving device is included with the transmission. If the device address does not match the intended address forthe data, the device ignores the data. If the data does match the device address, the data isaccepted. All devices receive the data but only the receiving deviceaccept them.
Bus Network Topology Advantages:1. Inexpensive and easy to install.2. Computers and other nodes can be attached and detached at any point on the bus without disturbing the rest of the network.3. Failure of one node usually does not affect the rest of the bus network.
Bus Network Topology Disadvantages:1. Because all systems on the network connect to a single cable or backbone, a break in the cable will prevent all systems from accessing the network.2. It is difficult to identify the problem if the entire network shut down.
Star Network Topology All the computers and other nodes on the network connect to a central device, thus forming a star.
Star Network Topology Two types of nodes that provide a commoncentral connection point to all the other nodeson the network are a hub and a switch. Hub / Switch
Star Network TopologyHub / SwitchThe device that provides a common centralconnection point for other devices on a network. All data that transfers from one node to another passesthrough the hub or switch. The hub takes a signal that comes from any node and passesit along to all the other nodes in the network.
Star Network TopologyAdvantages: 1. If one node fails, only that node is affected. 2. Nodes can be added to or removed from network with little or no disruption. 3. Easy to troubleshoot and isolate problem.
Star Network Topology Disadvantages:1. If the hub or switch fails, the entire network will be inoperable.2. Requires more cable than most of the other topologies.3. More expensive because of the cost of the hub/switch.
Ring Network Topology On a ring network, a cable forms a closed loop( ring ) with all computers and devices arrangedalong the ring.
Ring Network TopologyData transmitted on a ring network travels from node to node around the entire ring, in one directionToken passing is one method for sending data around a ringEach node takes a turn sending and receiving information through the use of a token.
Ring Network Topology The token along with any data is sent from the first device tothe second device which extracts the data addressed to itand adds any data it wishes to send.Then second device passes the token and data to the thirddevice, etc. until it comes back around to the first device again.Only the device with the token is allowed to send data.All other devices must wait for the token to come to them.
Ring Network Topology Advantages:1. The transmission of data is relatively simple as packets travel in one direction only.2. Cable faults are easily located, making troubleshooting easier. 3. The uses of token passing enables all nodes in a ring topology to share the network resources fairly.
Ring Network Topology Disadvantages:1. A failure in any cable or node breaks the loop and can take down the entire network.2. Data packets must pass through every computer therefore, this makes it slower.3. A ring network can span a larger distance than a bus network, but it is more difficult to install.
SUMMARY: BUS NETWORK TOPOLOGY DEFINITION ADVANTAGES DISADVANTAGES A bus network The break in the consists of a main cable(backbone) single central Inexpensive and easy to install. will prevent all systemscable (backbone), from accessing the to which all network. computers and other nodes connect. Other nodes can be It is difficult to attached or detached identify the problem without disturbing if the entire network the network. Shut down. Failure of one node usually does not affect the rest of the network.
SUMMARY: STAR NETWORK TOPOLOGY DEFINITION ADVANTAGES DISADVANTAGESAll the computers If the hub or switch and other nodes If one node fails, fails, the entire on the network only that node network will be connect to a is affected. inoperabled. central device, thus forming a star. Nodes can be added Requires more cables or removed from than most of the network with no other topologies. disruption. Easy to More expensive troubleshoot and because of the isolate problem. cost of hub/switch.
SUMMARY: RING NETWORK TOPOLOGY DEFINITION ADVANTAGES DISADVANTAGESOn a ring network, A failure in any cable Transmission of data or nodes breaks the a cable forms a is simple as packetsclosed loop (ring) loop and can take travel in one down entirewith all computers direction only. and nodes network. arranged along the ring. Cabel faults are easily Data packets must located, making pass through every troubleshooting computer, thus make easier. it slower. All nodes in ring More difficult to topolgy share the install than a network resources bus network. fairly.
EXERCISE:1) Which of the following statements describe about network topology correctly ?A. Nodes attached or detached at any point on the network.B. The failure of device on the network.C. Refers to the configuration of cables, computers and other peripherals.D. All of the above.
EXERCISE:2) On a __________, all of the computers and nodes on the network connect to a central device.A. Bus network.B. Ring network.C. Star network.D. All of above.
EXERCISE:3) On a star network, the central nodes that provides a common connection point for nodes on the Network is called the ____________. A. Hub. B. Personal computer. C. Printer. D. File server.
EXERCISE:4) On a bus network, if one node fails ________. A. Only that node is affected. B. Only the nodes before that node are affected. C. Only the nodes after that node are affected. D. All the nodes are affected.
EXERCISE: The transmission of data is relatively simple as packets travel in one direction only. 5) The statement above is correctly refer to the _________________. A. Bus network. B. Ring network. C. Star network. D. All of the above.