10

If your access points are independent, then yes, each time you connect to an access point, you need to authenticate. This happens automatically in the background but incurs some delay and the communication will be briefly cut. This is one of the major issues with stand-alone APs. To solve this, you can use access points managed centrally by a controller. In ...


8

It depends on how your access points are set up. If your access points are centrally managed by a wireless controller, then the wireless controller will synchronize authentication traffic from radius servers. The access points can reach the wireless controller for authentication every time it is required. The user won't experience an interruption when they ...


5

DHCP runs over UDP over IP - it works the same whether wired or wireless. The DHCP client sends out a discover broadcast (which is bridged or optionally relayed by the WAP) and the DHCP server returns an offer. All you need is L2 connectivity which Wi-Fi and Ethernet provide alike.


5

This level of install requires professionals, or at least experience. 1) 87 apartments means deploying dozens of access points (at least 1 per 3 apartments, possibly 1 per apartment, to be sure you would need to do a “site survey” with test APs and map signal strength). Best placement is on the ceiling. 2) Each access point requires ethernet cabling back ...


4

In infrastructure mode, WiFi access points send beacons every 100 mS announcing their presence. The beacon will contain the SSID(s) unless it's been disabled.


3

If there is more, then is there an official link where I can get this information? The official source is the IEEE 802.11 working group. You can download some IEEE standards for free with a simple registration as part of the IEEE Get program. The 802.11-2016 standard is available through GET program here: GET 802(R) Standards But you will also find useful ...


3

This is the same term used in two different contexts and it has quite different meanings. (it could also have other different meanings in other domains) In the context of radio frequency, yes it is literally a range of frequency. For example WiFi 802.11 (legacy/b/g) use the 2.4 - 2.5 Ghz range and so has a 0.1Ghz bandwidth. In the context of network it ...


3

It's quite easy to create a DoS attack on the 2.4 Ghz band. In fact, every time you turn on your microwave oven, you're creating a DoS attack on channel 9. There are wireless video cameras (and some old cordless phones) that also use the 2.4Ghz band. They also are good DoS tools. In practice, you have to be close to the AP or client in order to transmit ...


3

A similar question I found out that RadioTab headers are not part of any Dot11 protocol but are merely added by the network interface. And the reason I got the RadioTab headers on sample packets from Wireshark.org and not from my wireshark live capture is because some network adapters do not add RadioTap header while others do and the network adapter of my ...


3

Can I achieve this by using APs from different vendors? Possibly, but the problems you will face in working out interoperability issues will likely far exceed whatever disadvantages there are from using one vendor. In other words, it will be easier, cheaper, and more reliable to use a single vendor's solution. Most wireless vendors use a centralized ...


3

Option one is a "wireless bridge". Certainly common enough, but wifi is often too slow and unstable. Option two is similar to #1. (slow, and surprisingly easy to break.) Option three is code violation. You cannot put low voltage cabling in the same conduit as high voltage cabling. This is for safety reasons; there's very little concern of powerline ...


3

It doesn't affect the number of clients that can associate, but the lower the signal strength, the lower the "speed" (data rate). The lower the data rate, the longer it takes for a client to send a given amount of data. When that client is sending or receiving, no one else can be on the channel. So your overall throughput goes down.


2

You can assign access-point to access ports passing specific single Vlan . Assuming Vlan 10 Switch (config)#int f0/0 Switch(config)#switchport mode access Switch(config)#switchport access Vlan10 Switch(config)#no shutdown Wireless access point (WAP) is considered as layer3 device .


2

In enterprise what is commonly used is a centralized WiFi system based on a Wireless Controller and satellite access points. The controller is the sole configuration point, and it push the configuration on the access points. There's a standard protocol for this: LWAPP (Lightweight Access Point Protocol) defined in rfc5412 but not many products exists that ...


2

Well, it has everything to do with the clear to send and sending signals. In short: an AP basically tells a device it's listening to that device and is ready to receive (parts) of its message. This happens every other turn for all clients. look up: RTS/CTS (Request to send / clear to send) and you'll get a bunch of information describing this mechanism. It'...


2

802.11 uses the same 'core' frame as the other (IEEE) MAC protocols. It just adds a header of its own. It uses the same EtherType field and values.


2

Mesh ap's are able to use a wireless backhaul, without cable's, ap-mode or client-mode. They will form a wireless backhaul mesh with other ap's that support mesh-mode, if configured correctly. Technicaly a 'mesh' access point is an access point that support's 802.11s technology. sometimes "mesh" is a marketing term for 'access point supports assisted wifi ...


2

MIMO is different from LACP or static LAG in that it is located lower, within the physical layer. LAG bonds multiple physical links to a single logical one. It sits above the physical layer. MIMO extends the bandwidth of a physical link via multipath propagation over multiple antennas. It is somewhat similar to multi-lane wired links like the four-lane ...


2

IEEE organize their work into working groups or committees, one of which is P802 for LAN/MAN technologies 802 was simply the next available number when that group formed, although they first met in February 1980. These form working groups for more specific topics, like 802.3 for Ethernet, 802.11 for wireless LAN, or 802.1 for higher-layer LAN protocols (...


2

Could the frequency be a random number between the ranges or is it a defined set of numbers? When you transmit information (i.e. modulate a carrier frequency), you transmit signals that spread in a range of frequencies. This is what we call bandwidth or frequency range in the chart that @JFL posted. You don't just transmit on one frequency. In the US, the ...


2

A wireless radio network, is a shared medium. That means that only one sender at any time can be permitted to transmit. Multiple, simultaneous transmission would interfere with each other and garble the data. However, packet-switched networks transmit data in frames, (practically) up to 1500 bytes in size. Transmitting 1500 bytes with e.g. 600 Mbit/s takes ...


2

Will all the devices (which are labelled with 802.11x) use CSMA/CA? On a shared medium, you need something like CSMA/CD or CSMA/CA. Because Wi-Fi devices cannot both send and receive at the same time, they cannot use CSMA/CD to detect the collisions, so the use CSMA/CA to try to avoid collisions. How do each of these WAPs know which sub-carrier frequencies ...


2

It's right there in the footnote: Arbitrary port number is assigned to every AP from range 1024 - 65535 when the AP joins the WLC. The WLC uses the number as the Destination Port for CAPWAP Ctl/Data as long as the AP is connected.


2

IEEE 802.11s and EasyMesh are different and independent. 802.11s was created by IEEE some years back, when "mesh networks" were mostly infrastructure mesh networks, e.g., routers on top of buildings providing Internet connectivity over a region. These days, IoT is blossoming, and EasyMesh was designed partly to support IoT. There are differences in ...


1

CAPWAP is an application-layer protocol for wireless management. It's got its own DTLS encryption (in what you may call a sublayer). Usually, CAPWAP runs over the wired network between the wireless controller and the WAPs. If you run it over a (probably separate) 802.11 link, the encapsulating frames are additionally WPA2/3-encrypted on the data link layer.


1

The question posed is ill defined in some ways. We assume it is referring to one AP (if it is referring to more than one AP, then additional questions arise regarding the layout, etc., and interference between APs comes into the picture). 802.11ax, also known as High Efficiency Wireless, is designed to attack the problem of dense deployment scenarios, i.e., ...


1

Wi-fi requires two-way communication, so yes, proper operation depends on the transmit power and receiver sensitivity of both the mobile station and access point.


1

1/ Refer to Section 5.4 of this book for an in-depth analysis of the greenfield preamble. The GF preamble was introduced as part of the 802.11n standard, so it would be relevant only if you are planning to use several 802.11n devices at the 2.4 GHz bands. If there are a far higher number of legacy devices using 802.11b/g or the newer 802.11ax standard, then ...


1

Just some clarification of the terminology: Greenfield would mean a new deployment not needing to support some older WiFi physical layers. HT - High Throughput - is the official name for what is popularly known as 802.11n (802.11n is actually an amendment which technically is now no longer existing, as it has been rolled back to the main 802.11 standard, ...


1

I am confused about the meaning of the term 'Bandwidth' in a wireless transmission environment. The two are more closely related than you might think. The two most common definitions I could find are: difference between the upper and lower frequencies in a continuous band of frequencies This isn't quite right. A better definition is "a ...


Only top voted, non community-wiki answers of a minimum length are eligible