Four-step router selection (1)

Misunderstanding 1

CPU clock speed, the higher the better?

A processor is only a part of a vro, especially because it is the core device. Poor processor, poor router performance; but good processor, router performance is not necessarily good. It is like cooking, there is no good pork, there is absolutely no good braised pork; but there is good pork, there is no good soy sauce and good cook, still can not make good braised pork.

Second, the processor clock speed is only a performance indicator of the processor. To know the performance of the processor, you must also understand its bus width (16-bit or 32-bit), Cache capacity, internal bus structure, single CPU or multi-CPU distributed processing and operation mode. The so-called "using a professional communications CPU" is actually nonsense, but it is difficult to reveal the underlying structure in terms of professional terminology, because almost all routers use a professional CPU, the key depends on what kernel is used by the CPU and the internal structure.

Generally, MHz or lower frequency is relatively low; MHz ~ Center at MHz; high frequency at MHz or above. 80186. The ARM7 kernel processor is a typical configuration of the first-generation Broadband Router with low performance and is no longer used by mainstream vendors. The arm9-and MIPS kernel processors are currently the mainstream; the Intel Xscale architecture is an advanced network processor for high-end products.

Misunderstanding 2

Memory capacity. What is the better?

Similarly, memory is only an important part of a vro. Memory is used to store all the data in the computing process, and the memory is like setting up a room. Smart people are good at "Building a track in a shell", and useless things will never be placed in the room, 10 ~ A 20-square-meter apartment can place all the furniture and appliances needed at home. But if you change to a lazy bachelor, you can give him a set of two-bedroom furniture and appliances, make sure that he can't place it, and in a few days the room was full of rubbish and there was no place to stand on.

It is unreasonable to judge the performance of a Router Based on the memory size. It is equally important to use the memory scientifically. Excellent Software design can well plan and use the memory, however, vendors with poor levels do not even have the ability to design. Instead, they directly use the unoptimized reference software provided by the processor chip manufacturer. Of course, memory cannot be effectively planned and used. In addition, the memory can be measured in bytes or Bit. The difference between the two is 8 times the capacity difference (1 Byte = 8 Bit ), generally, B in upper case represents Byte, and B in lower case represents Bit, but some ulterior motives will be used here. The memory bus also has a narrow width and needs to store or take 4 bytes of data in the memory. If it is a 16-bit memory, it needs to be operated twice; if it is a 32-bit memory, it only needs to be operated once, the efficiency is doubled. Therefore, even if the bus width is different for memory of the same capacity, it will have a great impact on the performance of the router.

Generally, 1 Mbit/s ~ 4 M Byte is small; 8 M Byte is medium; 16 M Byte or above is large. In addition, if someone only tells you how many MB it is, be sure to ask whether it is Byte or Bit, whether it is 16-Bit or 32-Bit.
Misunderstanding 3

How many hosts are there?

Each network is very busy. For example, everyone in the internet cafe is chatting online and playing games. Almost all data is transmitted through the WAN port of the router, so the load is very heavy. However, if it is a corporate network, most people are busy designing, writing reports, and planning. At the same time, only a small number of people are using the network, and most of the data is flowing inside the enterprise network, therefore, the router load is very light. A vro that can be deployed on a 200 PC enterprise network may not be able to connect 50 PCs to an Internet cafe.

The number of hosts is only an estimate and experience. You must consider the actual network conditions. The actual performance depends on the test data, for example, Smartbits tests the number of pps (packets per second) of the LAN-to-WAN Throughput that enables 64-Byte packets in NAT ). However, the number of hosts is intuitive and understandable for common users. You must pay attention to the mistakes mentioned above when referring to this data. In addition, if this data is from a large manufacturer or reputable manufacturer, it is generally rigorous and highly reliable. If it is from a small manufacturer or manufacturer of miscellaneous brands, the general statement is vague and the credibility is poor.

Misunderstanding 4

What is the number of WAN ports?

After the basic hardware and software of a vro are determined, the processing capability or performance of the vro will be determined and will not change significantly as the number of WAN ports increases or decreases. However, there is a situation where the router processing capability is surplus to the WAN port egress bandwidth. For example, the router processing capability is 40 MB/s, And the WAN port egress bandwidth is 10 MB/s per line, due to the limited egress bandwidth, a single WAN port router can only have a throughput of 10 Mb/s, while a dual WAN port router can have a throughput of 20 Mb/s. From this perspective, it seems that the network performance has doubled, but this is only a problem of unreasonable network configuration. The router performance is always 40 MB/s, with no changes.

Conversely, if the router's processing capability is only 5 MB/s, both a single WAN port and a dual WAN port may only have a throughput of 5 MB/s. For example, a factory can make 10 thousand products a day, but there is only one freight truck that can only deliver five thousand products a day. In this case, adding a freight truck is very effective. However, if there are only three thousand pieces of output each day and two freight trucks are used, it will not work, increasing costs.

Some vrouters of different brands are currently on sale, but their performance is poor. A vro with multiple WAN ports must first be built on the premise that the vro itself can be strong, and the processing capability is surplus with that of the egress bandwidth vro. If the processing capability is limited, the multi-Wan port is purely a decoration.

TIPS: If the vro uses the ARM7 kernel or a processor with equivalent performance and the clock speed is less than 100 MHz, it can be basically determined that its performance is insufficient for multiple WAN ports.

Of course, many JS will also use their brains on throughput and Flash capacity to fool consumers. You should also pay attention to the purchase, so as not to trust your rumors and be cheated.