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Physical network refers to the arrangement of cables, computers and peripherals. The term also refers to the classification of devices connected to the network.
Stabbed a virtual network topology and the composition and structure. The assessment is not necessary for the appearance of the physical reality of the peripherals on your network. For example, a workstation at home Local Area Network connection with oval-shaped rooms, but we can not say that a topological ring. Integration of a computer network, a completely different card.
Establish a local network topology is divided into the following categories:
- Star topology
- Ring topology
- Bus topology
- Tree topology
- Network topology
- Hybrid topology
Complex and effective network can be built by connecting two or more of the above topology, and to address future topology. Traverse the network can cause many physical flaws or weaknesses in the system, because not all networks and network are often combined with a well put together.
Star network topology
The letters have been used in many local networks. In this way, any computer connected to a central center and each time during the network connection to point to a central unit. Each corner of the data or traffic transverses the network around a central center. Hubs will encourage or signal generator, which amplifies the signal to reach the distance.
As with any computer connected directly to the central center, a star network is considered easiest to set up and implemented. Easy to add additional machines is a big star. On the other hand, part of the enhancement powder to not function properly, the whole network fails, the error is because the weight of all computers connected to the network. When they say that this possibility depends on the topology, depending on the functions needed.
Star is also classified as multi-broadcast network or broadcast most (NBMA), depending on network technology, or automatically spread signals in the heart of all the rays, or simply an individual communication of the plug.
Network type network which is based on a physical star topology has one or more loop between the center button (volume) of stars and circuit courts, or the word "council, repeat used to expand distance maximum transmission between point-to-point connections between nodes and central nodes around the center support post button, or what standards are supported by the physical layer is based on a Why physical network. If the network is based on repeated characters may be replaced by a center expansion or conversion, hybrid network is created, which became the character known as hierarchical nature, although some documents not distinguish between the two topologies.
Types of networks, including the separate physical network, the letters are connected fashion line - which means "Daisy-chain" - without terminal central or top-level (such as two or more 'husband' center, along with stars that connected nodes or 'spokes').
Advantage Star Topology
- Star network topology is easy to manage the functions of its simplicity.
- The problem is easily placed in a logical star topology, and therefore easily resolved.
- Star has a very simple form, which facilitate expansion of the star-topology.
Disadvantages Star Topology
- Font entirely dependent on volume and activity depends on a central network or switch.
- the number of nodes and the cable is long delay networks.
Bus network is certainly the easiest way to create a computer network, and can be effective requires a minimum number of devices connected. Bus network, all computers are connected via a single cable-bye. Data collected every device cable. Although very simple and inexpensive to install or change the bus cable is the greatest risk. If the cable is lost or damaged, or corrupted, the whole network fails.
Bus network is limited to other factors. Bus network is more suitable for small networks. Is not very fast. More details on equipment, increasing network delay. However, the advantage of bus network if a range of computer, others will continue to work on the network. When two computers try to send messages during that time, data collisions can occur. These steps must be done to ensure that the two main cables in the same way your computer is not the time. For this reason, a small office network of bus limitations in two or three computers is ideal.
Bus network at the beginning and end of the cables start and end. It differs from other computer systems, such as a circle or a star. Each end of the cable, this device is called the terminator, the energy signal. This prevents the signal is considered off the cable and cause disruption of the signal to follow. You can add sites to a power cable is known as a common bus. This is similar in design to the topography of the fruit, but there is no central computer that all computers are connected. While the bus network is cheap and effective, as mentioned, suitable for smaller companies, which limits the number of jobs, and if the distance is not important. For larger networks, are considered different topology.
Types of networks where all nodes, linked by a common media, but exactly two endpoints (this is the bus ", which is commonly known as back or trees) - all All data are moved between nodes and distributed an average overall, and ready to move almost all nodes at once (regardless of the propagation delay)
Types of networks where all nodes, linked by a common means of providing more than two ends created by adding branches of both - the physical characteristics of the distributed bus topology is exactly the same way physical length of the bus topology (ie all nodes share a common communications Small).
Advantages and disadvantages of Bus Topology
- easy to implement and expand
- Well suited for temporary or small networks that do not require high speeds (quick setup)
- cheaper than other topologies.
- cost effective, because only one cable is used
- cable fault can be easily identified.
- Weight reduction by wire less
- limit the length and cable stations.
- If the problem is cable, the whole network fails.
- maintenance costs may be higher to tolerate.
- reduced performance in addition to the computer is added or discomfort.
- termination is required (loop must be closed path).
- a capacitive load (each transaction, the bus must be linked to achieve the maximum).
- It works best in a limited number of buttons.
- This is slower than the other topology.
Local network used in the ring topology, each computer is connected to a network or a closed ring. Every computer or computer has a unique address, can be used for identification purposes. Signals pass through each machine or a computer connected to the ring in one direction. Call topology often use a procedure through symbols used to control access to the network. This system can only be sent over the network simultaneously. Machine or computer, such as loop signal or signals Boosters reinforce the network. The shortcomings of the ring topology, the failure of the machine caused the entire network to fail.
Circle network, each device has exactly two neighbors for communication. All messages, go through the ring in one direction (or the time "or vice versa"). Cable or equipment failure could be a continuous circle, and the entire network. FDDI is implemented within a common network, SONET, or Token Ring technology. Topology calls can be found in some office buildings or facilities.
Advantages and disadvantages of the Ring Topology
- Very good network where each device has access to the characters and the ability to send
- behavior of the stars under heavy network load
- You can create a larger network using Token Ring
- No connection between computers on a network server to manage
- a workstation failure or bad port Mau can lead to problems across the network
- remove, add and adjust the device can affect the network
- Network card and Mau are more expensive Ethernet card and hub
- Much slower than an Ethernet network under normal load
Types of networks, where the home center (the hierarchy) is connected to one or more items in addition to lower levels of the hierarchy (ie, the level of Monday) is a destination - destination a node between the poles and at the level of the home "central" nodes connected to each tier a high level central 'root' node is one or more nodes of the lower level of the distribution system level (ie Tuesday level) is related to point-point, the center button is the highest "root", one of the buttons, no other node on the hierarchy (hierarchy is fully the general public.) for each node in the network with a certain number of nodes connected to the lower hierarchy than the next, a so-called "factors branches in a tree hierarchy.
Network based on hierarchical physical topology must have at least three levels of the hierarchy derived from a network of centers node and only one report of a hierarchical star topology is lower than the physical.
Hierarchical network topology based on the physical and the length of a branch elements are classified as a physical topology.
Branch factor f is independent of the total number of nodes, so the network nodes must be connected to other ports in the port button of the buttons are kept low, although the total number of big button - the impact of additional costs to the ports for each node completely dependent on the branching factor, and therefore can be as low as required without any effect on the number of button be.
Total point-point connection based on a hierarchical physical network topology smaller than the total number of nodes in the network.
If the nodes in a network hierarchy based on physical topology is needed to perform all the processing of data sent between nodes, the nodes of the hierarchy higher than do processing on behalf to other nodes with lower hierarchy. Network type is very useful and very encouraging.
Advantages and disadvantages of tree topology
- Tree topology is supported by various ad networks and hardware manufacturers.
- Point to point connection is possible Networks tree.
- network topology depends on the type of network cable.
- tree topology network entirely dependent on the voltage back to the main network. If the network fails.
- As a network, the fruits are large, difficult to establish, and may be granted after that product.
Network topology, including star, ring, bus, and the full technical requirements are many accessories and equipment. Among the cables construction is a major player in the network faster and less error. Speed network is directly dependent on the length of the routes and cables. The term "media" refers to the cable.
Variety of communications networks, depending on the size and thickness of the layer and metal. Here are some common network cable.
- Twisted Pair Cable
- unshielded twisted pair cable
- Shielded Twisted Pair Cable
- Plenum cable
Some of the topology, using a combination of two or more cable on. (Example: Hybrid topology)
Twisted Pair Cable
Twisted-pair cable is a cable and phone number, the most modern Ethernet networks. Many forms of circuit wiring, which can transfer data. Steam was launched to provide protection from crosstalk and noise in a few to come. When electric current flows through the wire, creating a small circular magnetic field around the wire.
If two wire circuit is located near each other, their magnetic field is exactly opposite. Thus, the two magnetic fields cancel each other out. To remove the external magnetic field. Wires twisted to remove the effect. Use the abolition of a rotating wire, cable design can provide effective shielding her a few Media Network.
Unshielded twisted pair cable
UTP cable is a medium composed of pair of wires. UTP cable is used in different networks. Each of the eight individual copper wires, you UTP cable is covered with an insulation. In addition, each pair of wires twisted around each other.
UTP cable depends only on equipment to minimize the impact of ending some signal loss caused by electromagnetic interference (EMI) and radio frequency interference (RFI). To further reduce crosstalk between pairs of UTP cable is a different wire pair number Tours. UTP cable must comply with specific details about the number of tour, or braids are permitted per meter (3.28 meter cable).
UTP cables are often installed on the post Jack 45 (RJ-45) connector. Eight-wire RJ-45 connector commonly used in computers, local area network (LAN), especially Ethernet.
Shielded Twisted Pair Cable
Shielded twisted-pair (STP cable technology) combines the cancellation shielding, and run wires. Both are packaged in a metal coating line. Four pairs of wire and then coated with metal or silver braid overall, usually 150-ohm cable. As specified in the installed Ethernet, STP reduces electrical noise cable (pair-to-pair coupling, or crosstalk) and from outside the cable (EMI and RFI). STP is usually placed on the data connection is STP, which is made specifically for STP cable. This may be the same as STP UTP RJ-purposes.
Although STP prevents interference better than UTP, it is expensive and difficult to install. In addition, a metal shield should be based on both ends. If it is not proper grounds, acts as a shield and antenna picking up unwanted signals. That any effort to end, STP is rarely used in Ethernet networks. STP is used especially in Europe.
Coax or coaxial cable, wireless and cable inner wire surrounded by a layer of insulating material pipe is often a flexible high dielectric constant, is surrounded by a layer of lead (usually a flexible software wire or thin foil), and finally covered with a thin layer of insulation outside of the parties. The term comes from the conductor and coaxial shield out of the same geometric axis.
RF Coaxial cable used for signal transmission applications, such as access to radio and TV antenna, connect the computer and cable television signal distribution. One advantage of using other methods, coaxial transmission lines, coaxial cable is an ideal field of electrical signals carried on only in the space between the wires inside and outside. This leads to coaxial cable installed next to metal objects such as gutters, loss of energy occurs in other lines and allow electrical signals from outside interference.
Proposed network topology
Since A2b is a company car with many branches and activities, tree topology is the business best and most appropriate. Among other things, the results show the best network topology for the following reasons:
- At least three levels of hierarchy in the network of trees, all the original work of the nodules.
- The two trees topology a significant role in topology, a linear and star-connected nodes.
- Tree topology to the total number of button functions on the network. No matter how many buttons are in each level. Nodes can be added to any level of hierarchy and no more limits on the total number of nodes.
- a higher hierarchy to perform tasks on the lower level network.
- Point-to-point wiring for individual segments.
- support a number of hardware and software venders.
- All computers can access a larger network of family and immediate.
- Best affiliate network.
Proposal for Network Media
Network of branches, requiring high quality cable to ensure the stability, speed data transfer and storage. I personally recommend the largest coaxial cable with a tree topology because, although important
- Supports coaxial 10-100 MB / s
- cable less is required.
- coaxial cable distance can be longer than any other cable
- It may be the distance between repeats, the stronger the network nodes
- coaxial cable in different sizes
- electromagnetic field signals from the space between the wires inside and outside
- Provide protection against electrical interference from outside