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All right, hey, guys, hey, thanks for coming back.
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I promise you that.
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Yes, I'll be as excited as I was before.
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Now, if you happen to notice, I've often mentioned network topologies, so I want to talk a little
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bit more about the details that we mentioned in network topologies.
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So basically, topology is like a well, I'll tell you what, it literally means a layout plan.
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Right?
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So a topology describes how computers connect and communicate with each other.
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The topology creates the physical and logical structure of devices that make up a network.
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Topology is the starting point for understanding the structure and the operation of different network
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technologies.
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So you could even examine topologies in two main parts, because, like I say, you've got the physical
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topology and that's the connection types of the network devices.
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So the cables used and their standards and the layout of the cables, the locations of the network devices
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on the network.
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These are all part of the physical topology.
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So secondly, we've got the logical topology, the communication types and the communication protocols
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of the devices on the network.
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Well, form the logical topology.
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So topology alone does not actually clarify many network related issues.
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Right?
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For example, the type of cable used its maximum length and how many computers will detect whether or
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not a cable is in use are not explained just by topology alone.
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However, over time, standards have been formed with the effect of market conditions.
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So there are different network systems using different technologies.
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These technologies even have names such as Ethernet, which you may have heard of token ring or FDI.
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So each network technology clarifies issues such as a type of the cable to be used, the maximum length
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in the bandwidth, along with the type of topology it uses.
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So topologies are generally divided into these two, right, physical and logical.
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But who said that in the back, yeah, OK, good.
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That's a good question.
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So let's actually dig into some of the greater details of this physical topology.
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So the physical layout of the devices that make up the network and the cable types used form the physical
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topology.
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Right.
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They're basically six types of physical topologies.
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There's common path ring star, extended star mesh and tree.
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So take a look at this first one bus topology.
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Now in bus topology, communication is carried out on a single cable, and network devices are connected
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to this cable.
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A single cable, can we call this segment a backbone or even a trunk?
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The data sent in the network continues on the line until it reaches the destination or arrives at the
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Terminator and passes by all devices on the network.
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The bandwidth of the network is shared by the devices on the network.
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So basically, coaxial cable is used in this topology, and it's one of the topologies with a lowest
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network performance, by the way.
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And the maximum distance is 185 meters when using thin coax cable and 500 meters when using thick coax
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cable.
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Up to 30 network devices can be found on one of these network.
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So in this topology, every device connected to the network listens to every transaction and data transmission
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on the network.
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And if its its own transmission, it gives and receives.
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Before any device on the network sends a data packet.
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It's got to make sure that the line is not used by anyone else.
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If two different devices send data packets to the network at the same time.
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Well, you've got a conflict occurring in the priority order will be decided between the two devices.
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It's like a boxing ring or something, but it definitely reminds some of maybe the parents and grandparents
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of what they used to have for telephone lines.
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Right?
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The Common Party line.
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Anyway, there are some advantages.
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It's a very easy day to set up the network and connect your computer to the network to expand the network.
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In fact, it might even just take a morning.
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It can be set up very quickly for networks that don't require high speed.
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Not everything does.
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And it certainly requires less length of cable.
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Doesn't even need an external device, therefore they don't keep costs down.
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But then you got to weigh it against the disadvantages, the cable length that can be used for the main
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line and the number of network devices that can be connected to it.
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Very limited.
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Any damage to the backbone cable affects the entire network and then network becomes inoperable.
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A Terminator must be at the end of the cable.
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When there is a network problem, it can be difficult and time-consuming to detect and fix the problem.
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It is not usually used for a stand alone building network solution.
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And it's way slower than other topologies.
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Networking, adding a new device increases data density and decreases performance for everyone.
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Now, number two, we've got ring topology.
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So this ring topology is very interesting, it was developed first by IBM and the layout of the network
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is in the form of a ring.
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Data transmitted over the network passes through every device on the network until it reaches its destination
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because there is only one path between the devices on the network.
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So in this topology, the attenuation of the signal on the network is at the lowest level because the
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signal is strengthened at each device it encounters and transferred to the next device.
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So data transmission over the network is done with the help of a signal called a token.
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It's a three byte signal.
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The token is constantly circulating on the network, and the device that will send the data uploads
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the data to the token.
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If the token is empty, it leaves the network again with the destination address.
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But the failure of a network device on the ring will cause the entire network to crash.
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But as it turns out, ring topology is also divided into two.
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There's the classic ring model.
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OK, it's logically created by connecting all nodes together in a circle.
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If a computer in the ring fails, all network communication is cut off, but collision probability is
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low.
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Now, coaxial cable was used in the first ring topologies, but currently UTP and STP cables are used
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in ring topologies.
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First ring topologies.
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It works at four megabits per second, then 16 megabits per second.
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And there are some Ethernet cards now that are suitable for ring topology and those who work at four
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or 16 megabits per second, so.
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There you go, a bit more flexibility with either not.
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All right, so the next apology on our apology tour is the star wired ring model.
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So in Mao or Multi Station Access Unit, data goes in a circle.
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Right?
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But while hubs transmit all incoming signals to all nodes, mouths transmit incoming signals in a ring
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form in only one direction.
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That way, all nodes in the network receive the token.
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So naturally, there are some advantages.
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It's thanks to these tokens at each device is equal in data transmission.
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No servers needed for connections between devices.
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And growing the network has little impact on performance.
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But weigh that against these disadvantages, you've got problems with any of the network devices will
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affect the entire network.
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Network interface cards and mouse are more expensive than an Ethernet and a switch.
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Adding changing or removing devices to the network will affect the entire network.
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Next stop, number three, the star topology.
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Now, this I mentioned before is the most widely used physical network topology today.
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Every device on the network is connected to the switch or hub in the center.
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So roaming of data on the network will depend on the central connection device.
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So information sent from a network device will first be processed in the central connection device and
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then gets routed to the destination from their.
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So it offers higher performance compared to the bus topology.
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Now, a problem in the hub where this which.
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Will affect the entire network, but a problem in a network device will only affect that network device.
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The rest of the network is not affected by this issue.
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Twisted pair cables are used in star topologies.
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The distance of the network devices to the central connection devices at most 100 meters.
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Now the problem of any device in the network can be easily identified by just looking at the lights
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on the central connection device.
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So when a device is added to the network, the corresponding port light on the harbor switch should
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be lit.
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And of course, it comes with many advantages.
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A few of them are adding new devices to set up an expanding network is really easy.
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Any problem with one of the network devices will only affect that device.
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Network management and troubleshooting are easier to.
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Some of the disadvantages include requiring longer cable lengths compared to a linear topology.
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When a harbor switch fails, the entire network becomes inoperable.
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They are more expensive to install than linear cousins due to devices such as hubs and switches.
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So now we come to number four, the extended star topology.
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This is fairly larger and basically enlarged version of the star topology.
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The network is expanded by adding new or additional hubs and switches to the hub or switch in the center.
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Five, we've got a topology very popular these days and mesh topology, every device in the network
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is connected with other devices.
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It's mostly used in windows or wide area networks when used in LANs, the local area network.
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Each device in the network does not need to be connected with the others.
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So in this topology, all computers are connected to other computers by a separate cable.
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Now, theoretically, it's the ideal connection time, however, since the number of cables in-between
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increases exponentially is the number of terminals increases.
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Well, it's only used in very special situations in between a small number of computers in real life.
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There are some advantages since there is a connection to other devices over each device.
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Communication takes place over other connections, even if there's a problem with any one line.
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Now, since the devices are directly connected to each other, data transmission speed is pretty high.
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Expansion of the network can be done without affecting other nodes.
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But of course, he got to weigh it against the disadvantages, since each device has x minus one connections.
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There must be so many ports on the devices which increase the cost.
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Cost and complexity are high because way too many cables get used.
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Now, here's something interesting number six, the hierarchical tree topology.
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This is used to connect different networks, usually networks in star topologies.
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Thus, networks can be enlarged.
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But unlike the extended star topology, it does not need a central device to connect the networks.
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It has the characteristics of common path and star topology.
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There is a hierarchical order among the devices on the network in the tree topology, of course.
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And at the very beginning of the network is a device that acts as a route, which we will remember from,
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well, the way trees grow.
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Right, they start at the roots.
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Now, connections from other networks are not made on the route.
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The branches.
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See, here's the metaphor again of the tree represent networks of different topologies and are connected
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by the trunk of the tree.
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Now, this topology is often used to create backbones of very large networks.
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And some advantages will be easy to manage and maintain as a network is segmented.
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If you're well trained in it, that is you don't have to worry about it.
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Perhaps not yet, anyway.
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Hardware and software from different manufacturers will definitely work harmoniously.
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It's easy to expand the network, easy to detect and fix errors.
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And a problem in one of the segments will not affect the other segment.
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Of course, there are some disadvantages.
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The length of each segment is limited by the cable used cabling is often difficult compared to other
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technologies.
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And the problem that will occur in the backbone affects the network traffic in all sections.
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It is difficult to install to regulate and maintain.
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So now let's talk a little bit about the types of logical topology.
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So the communication types and communication protocols of the devices on the network will form this
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logical topology.
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Two types of logical topology are commonly used.
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One is a broadcast topology.
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So each computer on a network can release information to the network environment to send information
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to one, to several or to all computers on the network without giving any particular priority.
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It all works with a principle of first come, first served.
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There are three different working modes, so according to this method of delivery, a it's a unique
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cast communication.
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So communication from one computer to only one other computer.
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B is multicast communication, so this is a form of communication between one computer and then more
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than one computer.
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See, broadcast communication.
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It's a type of logical topology where communication takes place from one computer to all the other computers,
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right?
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So we also have to talk about this number two token ring topology.
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So token, right?
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These are deposited on the network by a server.
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This token governs access to the Network Environment Data Center.
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The network is transmitted with his token.
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Therefore, collisions in the network are prevented.
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As the token travels over the network, it stops by every device and checks to see whether there's data
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to be sent and delivered almost like your your Postal Service or not.
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Anyway, tokens are three bytes of information circulating between these notes.
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All right, so that does it for all of this, you have now taken a marvellous tour of topology.
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We've also covered peer to peer network architecture, the client server architecture, file servers,
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database servers, transaction servers, web servers.
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We covered proxy servers, pans or personal area networks, LANs or local area networks, mands metropolitan
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area networks and web and wide area networks.
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Wow.
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There's a lot, huh?
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Because we also did VPNs or virtual private networks, cans, controller area networks, sands storage
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area networks, bus topology, ring topology, star topology, mesh topology.
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And then we kept it all off with the hierarchical tree topology, which, OK, try to say that three
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times fast.
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And then we wrapped it all up with broadcast apology and token ring to apology.
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Now, if I had told you we were going to learn all of that.
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You would never have started this, right?
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But you see how just one thing builds on another and another, and then before you know it, it's like,
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Wow, you actually know something now.
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So thank you so much for listening and playing along.
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We've got a whole bunch covered, and I hope you enjoyed it as much as I did.
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But there's more there's always more.
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All right, so I want to see you in our next lesson.
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Until then, have a great day.
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