Wednesday, January 5, 2011
【School】 cafes weak】 switch selection guide..
<br> <BR> switch as the core equipment of Internet cafes can be seen as data transmission between computers overpass.. There is no doubt that the performance and capacity overpass will fundamentally affect the entire network transfer rate.. For owners of .Internet cafes, the switch can be regarded as network devices are expensive, so the switch in the purchase must be selected very carefully.. Internet cafe owners to buy <BR> <BR> principle focus is the network's stability, speed, and .capital investment, so choose the switch for the cafe, it should follow the following principles: <BR> stability overrides everything <BR>. stability should be the Internet cafe equipment purchase the basic principles to be followed, the switch is no exception ... Switch performance can be poor, narrow bandwidth, but never can often fail, especially not often dropped.. The reason is simple, if the switch fails, all computers within the Internet cafes will immediately disconnect from the network, "network" .it also worthy of the name of the.. Intermittent network environment rivals will quickly rushed to the consumer.. <BR> Pursue the highest price <BR> "to the value of every penny well spent" is the pursuit of objectives .for each operator.. Value for money principle in the following areas: <BR> first port density.. In a variety of performance parameters of the same circumstances, the greater the switch port density, the less the cost per port.. In .other words, a 48 port switch 24 ports than the two switches have cheaper, therefore, high-density port switch often have a higher cost.. <BR> Second, performance and functionality.. The better the performance, features more rich, .natural prices higher.. In fact, the scale bars are often not great, not particularly rich in a variety of network applications, the requirements for network security is not very high, so the general 100Mbps switch completely to take a leading role fool.. .<BR> Third, consider the differences.. Some switches (center switch) for connecting other switches and servers, while some switches (workgroup switch) are directly connected to the computer, so the switch should choose different locations different properties of the product ... The only way to give full play to the highest performance for each device.. When the computer more than 200 Internet cafes in Taiwan, the proposed acquisition of a three-layer switch as the central switch.. <BR> Fourth, .the company brand.. United States, China mainland and China Taiwan region has produced the switch vendors.. Among them, the United States, the highest price, most feature-rich, the strongest performance, followed by China and China Taiwan region products. .. Internet cafes do not have as much function switch, so well-known brands in China are often the most cost-effective.. <BR> <BR> The game is a whole should be harmony between the switch, match, compatibility ... Port speed should match, if the central switch with 1000Mbps port workgroup switch with 100Mbps ports but, then, using 1000Mbps port is undoubtedly a waste.. Different brands of switches, the technology used should be compatible with each other and jointly follow the .same international standards, so that the network management and technology possible.. In short, should be a harmonious connection between the switch to play to their maximum performance.. <BR> <BR> Issues to consider when purchasing a rational purchase, .reasonable budget is a successful Internet cafe owners must follow the principle.. Therefore, when the switch in the purchase should be based on investment amount and the actual needs of Internet cafes, to seriously consider the following questions: <BR> ● smart or .stupid <BR> Managed Smart Switch is the switch, the switch is not a fool managed switch ... With management features, the switch can achieve a variety of switching technology, application of complex network settings, control user access to the switch, .ensure network security, improve network transmission efficiency.. Internet cafes in the center of large switches with management functions should be used and implemented by VLAN communications between VLAN, and optional workgroup switches usually do not take into account management functions, can be cheap fool of .switches.. <BR> ● 1000Mbps or 100Mbps <BR> no doubt, 1000Mbps port can provide higher bandwidth, more suitable for multiple concurrent access, and multimedia data transmission, but its prices are often higher than 100Mbps port 10 to 20 times .more expensive ... Therefore, unless there are special needs, recommend choosing 100Mbps switch.. Symmetric or asymmetric <BR> ● <BR> symmetric switch exactly the same rate on all ports, such as all the 100Mbps or 1000Mbps; symmetric .switch port rather than at different rates, such as the part is 100Mbps, part 1000Mbps.. When deciding 1000Mbps network backbone, the center switch should choose symmetric 1000Mbps port switch for connecting workgroup switches and servers; working group should be chosen asymmetric switch switch, .1000Mbps switch port for connection to center, 100Mbps port is used to connect. computer.. <BR> ● selection of the modular switch port <BR> addition to higher performance, but also have greater flexibility to choose a different network environment, .according to the modules to provide different amounts and types of ports (Figure 1. expressed as a modular port).. Poor performance of fixed-port switches, can only provide a fixed number of ports, only a specific type of network, but the .price is much cheaper.. However, the cafe's environment is relatively simple and does not require high flexibility and scalability, therefore, more suitable for fixed-port cafes. <BR> Figure 1 <BR> ● stacking and stacking or cascading cascade .is connected <BR>. Two-port switch to expand the means.. The so-called stacking, is the use of specialized modules and cables, the number of switches stacked together, use them as a switch and management of high-speed .connection.. The so-called cascade, is the use of common cables connected to the switch (Figure 2), to achieve mutual communication.. By stacking mode, the connection between the switch bandwidth is usually greater than 1Gbps; cascade, the maximum .bandwidth of only 1Gbps.. However, the stack need the help of specialized modules and cables to achieve, so the price is relatively high.. Bars recommended by cascade.. <BR> Figure 2 <BR> ● desktop or rack space .<BR> as Internet cafes are very valuable, therefore, should minimize the space occupied by network equipment.. Rack switches should be selected, and it is fixed in a standard cabinet (Figure 3), can save valuable space, but also facilitate .the provision of power to achieve management.. Figure 3 <BR> <BR> <BR> main parameters during the purchase, should pay attention to the following main parameters: <BR> ● <BR> port workgroup switch ., such as to buy, recommended to choose a 24 or 48. port 10/100Mbps switch, the center recommends that you select a fixed port switches, 100Mbps three switches.. Although 1000Mbps port has a higher transmission rate, but the reasons do not .recommend purchase because of price.. In addition, Internet cafes are usually small scale, the distance from the switch to the computer normally in the 100 meters, therefore, cheap RJ-45 port is more suitable for Internet cafes.. <BR> .● Forwarding rate Forwarding rate is switch <BR> a very important parameter, which fundamentally determines the switch from forwarding rate.. Forwarding rate is usually "Mpps" (Million Packet Per Second, millions of packets per second) to indicate that the .second can handle the number of packets.. The higher the value, the stronger the switch performance.. <BR> ● <BR> backplane bandwidth backplane bandwidth refers to the switch interface processor or interface cards and data bus between the maximum possible .amount of data throughput.. Since all communication between the port must be done through the backplane, all backplane bandwidth to be able to provide concurrent communication between the port bottleneck.. The greater the bandwidth, can be provided to the communications port the greater the .available bandwidth, faster data exchange; bandwidth is smaller, the communications port can be provided to all the smaller available bandwidth, the slower the speed of data exchange.. Therefore, the greater the bandwidth backplane, switch the transmission rate is faster.. < .; BR> ● cache buffer for temporary storage awaiting <BR> data transmitted.. If the cache capacity is small, when a large amount of concurrent access, the data will be discarded, resulting in network communication failure.. Only the larger cache .capacity, we can multicast and broadcast traffic in large cases, provide better overall performance, while ensuring the maximum possible throughput.. At present, almost all of the cheap switches are used shared memory structure shared by all ports the switch memory, balance the network .load and prevent packet loss.. <BR> ● MAC address of each switch in the number of <BR> maintains a MAC address table, record the MAC address and port mapping to access requests under the MAC address are forwarded directly to the .corresponding port.. The number of MAC addresses stored more data forwarding, the higher the speed and efficiency, anti-MAC address of the stronger supply capacity overflow.. <BR> Mastered several parts described above knowledge, you will be able to improve .the understanding of the switch bar to know how to choose suitable products.. <BR> The Editor: With the expanding scale of many Internet cafes, the continued expansion of the network structure to build a stable and efficient network environment has become many Internet .cafe owners have to face facts.. At this point the owners need to carefully select, carefully chosen, with cost-effective products to build an efficient network.. This should be able to buy the majority of the owners when the switch bar to play .the role of great help.. <BR>..