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Nowadays, wireless network has become more popular as science and technology develop rapidly. we even cannot live without the wireless network, which has attracted SPOTO’s attention. SPOTO involves in the IT training and gives you the best and most professional tutors to train when you learn the CCIE, CCIE Lab, CCNA, CCNP, and CISSP Certification exam. The following is how to set up a wireless network that you should master.
Step1: clear requirements
Compared to office cable, wireless is more complicated.
Wired only needs to calculate the number of points, access, and convergence ratio, and rarely care about speed, application, and other issues, because now it is basically Gigabit access, 10 Gigabit to core architecture, more than enough in the office network environment.
And wireless can't see, can't touch, there are many factors to consider. Whether it is as a Party A engineer in the demand or a Party B engineer to consider the needs of Party A, there are many aspects to consider:
1. Clear coverage:
A company doing WIFI coverage is not necessarily full coverage, which needs to be clear in advance. For example, the WIFI signal of a building covers which areas, whether the public area covers, whether the bathroom is covered, the corridor, and whether the elevator is covered, otherwise it will be different from the imagination.
For example, the US group does not cover the WIFI coverage of the bathroom, and the hospital needs to cover the stairs. This needs to be combined with the business and the scene, rather than taking it for granted.
2. Clear signal standards:
For wireless, different services have different requirements for wireless signals in different scenarios. We know that wireless is two-way. Both the AP and the terminal have both directions for sending and receiving. When we stand at the perspective of the terminal, we can receive the AP signal, but the signal AP is not necessarily received.
For example, a MAC PRO notebook has 3 transmitters and 3 antennas, and a mobile phone has only 1 transmitter and 1 antenna. Their capabilities are different. At the same time, the transmission power of the antennas of different terminals is also different.
This requires us to consider the business usage scenarios when designing the WIFi signal. For example, all mobile phones require the density of the AP to ensure that the mobile phone receives and transmits normally, which is higher than the coverage signal standard of the computer.
3. Identify the number of terminals:
The capacity of an AP is limited. In today's enterprises, the stations are very dense, and the terminal owned by one person is not just a computer. One laptop and one mobile phone are normal. very. If it is a mobile phone testing department, more than a dozen people are normal.
Therefore, to determine how many square meters of coverage, how many people, how many terminals per person. In the author's experience, in the design stage, the number of wireless terminals in the office network should be calculated by multiplying the number of workstations by 2.5 to 3 terminals per person, and the conference room and public areas should be added.
4. Clear WIFI rate:
We must know that wireless is a half-duplex technology, which is equivalent to a HUB in a wired network cable, not a switch.
The rate in the so-called 802.11 protocol is only an access rate, that is, the nominal one at most in the case of one AP and one terminal. The real rate is also multiplied by about 0.4 on this basis (half the half-duplex). Some management frames and control frames are sent, which is sent by the AP itself, but it will occupy wireless resources. That is, the actual wireless throughput is only about 40% of the access rate.
For example, a 3X3:3 spatial stream of 802.11N APs can support up to 450Mbps. Its real throughput is that with only one AP and one 802.11N terminal, the transmission file can reach 450X0.4=200Mbps, 200Mbps. /8=25Mbytes, which is equivalent to a wired access rate of 200Mbps. This real transfer rate is called throughput, which is the real speed.
When the number of users of this AP increases, the 200 Mbps will be shared. If 20 terminals are using the WIFI of this AP at the same time, the average Throughput of each terminal is only 10 Mbps, which is equivalent to receiving a 10 Mbps wired network port. It must be noted that the AP is equivalent to a HUB, not equivalent to a switch, it is a half-duplex device, and the wireless environment is a half-duplex environment.
Therefore, at the beginning of the design, according to the number of people, the business, the design can guarantee the roughly wireless Throughput of each terminal. If some services require high bandwidth, it is not suitable to use wireless or reduce the number of terminals per AP service to meet the requirements. Some high-priority services also need QOS to guarantee.
5. Clear safety requirements:
Because wireless is exposed to the air, it is actually accessible to everyone. This involves a security issue, usually considering both encryption and authentication. Encryption and authentication are two things that you should not confuse.
Encryption is to convert plaintext data into ciphertext on a computer and then transmit it to the AP. It does not matter if it is listened to by other wireless terminals. In an environment without encryption, a PC sends a message to a wired server via the AP through the AP. The other PC can use the packet capture software to capture the data and directly see the contents. After encryption, it still remains. It can capture packets, but all of them are ciphertext, which guarantees the security of wireless data transmission.
For example, AES is an encryption algorithm used wirelessly. Authentication refers to which devices are allowed to join the enterprise's wireless network, using the use of authentication methods, mainstream including 802.1X, MAC address authentication, WEB authentication or a combination of them.
6. Clear SSID and roaming design:
At the beginning of the design, we must consider how many SSIDs to plan, and what is the role of each SSID. It is generally recommended that the number of SSIDs be no more than four. For each SSID added, the AP sends management and control frames based on the SSID, which increases the waste of the wireless band.
At the same time, consider roaming when designing. If there are 10 APs and one SSID is used, the PC will automatically switch from AP1 to AP2. If 10 APs and one APID per AP, the employee needs to manually switch the SSID.
7. Clear VLAN and IP design:
In the wireless design, you should also consider the IP address and VLAN planning, that is, how many terminals, how many IP addresses to reserve, and whether to use the DHCP service. Usually, one VLAN corresponds to one IP subnet, and each SSID uses one or more VLANs and subnets. Not all SSIDs are in the same VLAN and subnet. Different VLANs and IP subnets will be used for the same SSID on different floors (this can be done by technologies such as AP-Group).
8. Identify the wireless protocol and channel:
Nowadays, there are a lot of 802.11 technologies, but we have to choose according to the actual situation of our enterprise at the beginning of the design. For example, whether the enterprise equipment now supports 802.11AC, whether the enterprise has the demand of 802.11AC, or between 802.11AC wave1 and wave2 How to choose, whether the enterprise still has an old wireless terminal to use. From the channel, how to choose 2.4G and 5G, although the AP is now dual-band, the terminal still has only 2.4G terminals, so whether the enterprise is to open dual-band or only 5G is necessary to investigate and clear of.
Step 2: Site survey
After clarifying the basic needs of wireless, the next step is to conduct site surveys. That is, how to deploy an AP within a specified wireless coverage, how many APs to deploy, which channels to use, and how many terminals to use.
1. Preliminary estimation:
The CAD layout design of the building floor is usually taken out by the administrative or property. IT proposes the number of wireless terminals and access rate requirements, and then estimates the number of APs. Common methods include engineer human assessment, evaluation using wireless network vendor software, and evaluation using professional wireless survey software.
2. Field survey:
After the rough assessment, go to the site for a site survey and select a floor or some point for wireless testing. Take an AP, put it at the beginning of the design, power up, broadcast the SSID, specify the target transmit power, and measure the wireless signal around the notebook to see if it meets the specified design criteria. Some special areas such as stairs, corners, edges, leading offices, and conference rooms are all subject to key tests.
To ensure that the results on the site are consistent with our design expectations. At the same time, pay attention to the environment where the AP can be installed. After all, the actual environment is not known on the CAD map. For example, some places may not be able to install the AP at all, and some places do not want to install the AP due to aesthetic problems.
After the site survey and evaluation is completed, the AP is added or the AP point is modified in an unreasonable place to complete the final AP point map. This is the final AP placement version. But we also need to pay attention to reserve some Buffer when the weak power cable is used. Because there may still be some variables after the employee moves in.
step 3: program design
After completing the wireless survey, you can design the overall solution for wireless.
1. Equipment selection:
After completing the site survey, combine the requirements analysis of the first step to select the wireless device. There is a problem in the selection of wireless, that is, the standard parameters are all supported by all manufacturers, such as the 802.11 protocol supported by the AP, throughput, and the number of machines. The official parameters of several network vendors are almost the same and cannot be compared. But the experience is not the same, I suggest that you can test in the field to test APs of several different brands.
For example, look for 100 terminals (Windows, Mac, Lenovo, DELL different brand models notebook, iPhone, Huawei, Android, Samsung, Xiaomi different brands of mobile phones, software versions are also different) and then look for different manufacturers of AP, run the actual traffic in Above, to test parameters (such as 802.1X authentication, MAC address authentication, PSK authentication) and performance (delay, packet loss, jitter, bandwidth) and other parameters.
The author's suggestion in this regard is that the use of Cisco or Aruba wireless products will be more stable, of course, the price will be more expensive than domestic. In addition to wireless products, pay attention to the choice of POE switches. Now the supply of the new 802.11AC requires a power supply for each AP30W. This should also be noted. This stage is mainly to choose wireless AP, wireless controller and POE switch.
2. Business design:
Implement the SSID design of the previous plan, a total of several SSIDs, what are the names, whether to broadcast, what method to use for encryption (AES or TKIP), what authentication method (802.1X, PSK, MAC address or WEB authentication), each Which VLAN corresponds to which VLAN, which IP subnet, whether to use DHCP, whether to do QOS, whether to use ACL, whether to limit the speed of the network.
3. Channel design:
Which frequency bands are used by the entire network, for example, both 2.4G and 5G are used, and some scenarios use only 5G, for example, 2.4G is turned off in a high-density area. How to design the frequency band, how to stagger the channel so that the channels do not overlap, such as 1, 6, 11 or 1, 5, 9, 13; Which channels are used by 5G, whether to bind the channel, not bound, 40MHz binding or 80MHz Bind, or 160MHz binding.
4. Highly usable design:
What high-availability design is used throughout the wireless system, including system-level high availability, such as wireless controllers for dual-system deployment, switch-to-two-node deployment, or AP registration to different controllers, and RF-level design redundancy includes The separated APs are registered to different controllers and use different POE switches to cross-connect to achieve actual redundancy.
Step 4: Wireless implementation
After all the plans are finalized and the equipment is purchased, the workers are arranged to carry out construction according to the drawings and install the AP. The installation of the AP requires the MAC address and serial number to be recorded in advance, and each AP is named and tagged. To be in which position the AP is, it must be consistent with the drawing.
The network engineer debugs the wireless device, and the AP goes online. After all the online is completed, the signal test is performed. Finally, the RSSI of each area is indicated on the icon (the following is a detailed description of this parameter in the following section), that is, the received signal value.
Employees plugged into the office and started using wireless.
Step 5: Wireless Optimization
After the wireless implementation is completed, the wireless is gradually optimized:
1. Optimization of AP deployment: that is, adjusting the location of individual APs or increasing or decreasing APs according to people's reflections. This is a frequent problem in wireless deployments, and wireless is almost impossible to deploy at once;
2. RF level optimization: that is, adjust the wireless channel, power, access rate, and so on.
