626WiFi

     I started my career in IT as a contracted help desk. I worked for a "value added reseller" that would contract out members of their helpdesk to one or more companies. Meaning I would take phone calls for any number of technical issues for many different companies. At one point I was contracted to three different companies. I would work on generic computer issues, networking problems, printers, SOHO routers, etc.      From there I obtained both my Bachelors degree and the CCNA. This allowed me to obtain a role at Walmart Global Tech as a Wireless Network Technician. The CCNA weighed very heavily compared to my Bachelors to my surprise. While at this team, I worked on Cisco, Juniper, Mist, and Meraki access points, wireless controllers, switches, and routers. This team placed a huge emphasis on the importance of CWNP certifications. Since I was itching to get into an engineering role, I began studying for the CWNA using David Coleman and David Westcott's...

      I'm regularly asked to recommend an access point for an installation or refresh. The information that typically comes up when discussing the key differences between two different AP types are the radios. I go into the differences between WiFi 6 and 6E, making sure the customer is aware of the benefits of 6GHz and how it can help their wireless when implemented well, it is NOT a silver bullet to fix bad designs. After these discussions, the key difference between many different AP models tends to be the radio count. Whether the AP is 4x4:4 or 2x2:2 in most cases. What makes one better than the other?     It's difficult to talk about radio chains without talking about MU-MIMO. I have posted about this in an earlier discussion. Basically, it is rare to see the advantages of MU-MIMO. So, if that's not a large benefit, what is the driving factor for choosing a 4x4 AP over a 2x2? 4x4:4 Clients     The most obvious benefit would be if you're using ...

  Multi User Multiple Input Multiple Output      MU-MIMO was first introduced in 802.11ac as an optional feature. In .11ax, downlink MU-MIIMO is mandatory but uplink MU-MIMO is still optional. There has been a lot of marketing around this and many clients do not see the benefit of this. Let's look at what MU-MIMO is, how it operates in a perfect world, and if it's worth the hype.      At a basic level, MU-MIMO was supposed to solve some inefficiencies in Wi-Fi. When you think about it, the biggest thing that plagues wireless networks is the nature of the technology, it half duplex. One client transmitting at a time. So that means an AP or a client can transmit on one channel at a time, competing for the same airtime. This causes data to move much slower than it could, and it gets drastically worse the more clients that are on a single AP/channel. So how do we solve this? We cannot have collisions (two clients transmitting at the same time) or else traf...

 Within ExtremeCloud IQ (XIQ), you can edit tons of advanced radio features. In this post, I'll go over some of the main "nerd knobs" that you can edit. Let's start with the some of the most important tuning, transmit powers and channel selection: By default, your 5GHz radio will have a generic configuration, this included a txPower range of 5-20dBm. I have seen APs from many vendors prefer to stay towards the upper end of their power range. Due to this, it is best not to leave this at default, especially if you're in a dense deployment. I've seen many schools have one AP per classroom, in this situation, it can be detrimental to keep the max at 20dBm. Tune this down to your needs and if at all possible, conduct a site survey to validate what txPower you should be using. Next, your transmission power floor set to 5dBm by default, again, the AP may prefer to stay on the upper end of the max, but still tune this to where you see fit. Max power drop will determin...

Vendor Recommendations on High Density Design - 5GHz      According to CWNP's CWDP certification study guide, wireless engineers agree that the Aruba Networks high density design guides are among the best in the industry. Due to this, recommendations will be pulled from Aruba's design guide and CWNP's recommendations form their various certification teachings. This post will focus mostly on the need for smaller channel widths in high density deployments. Channel bonding is one of the very important considerations when deploying to a high density environment. Upsides to channel bonding:      Bonding channels increases throughput, which can improve performance. Thus, the difference between using 20 MHz and 40 MHz channels is throughput. 40 MHz has higher throughput, around double that of 20 MHz and 80MHz has higher throughput than 40MHz thanks to channel bonding. In order to achieve the highest data rates available in 802.11ac, 80MHz(867Mbps) or 160MHz(1.7Gbp...

  Disassociation Type: 00 Subtype: 1010 The Disassociation frame is very similar to the Deauthentication frame, however, it does not make clients completely restart the 802.11 state machine. Instead, it just requires clients to go through the association process, keeping the previous 802.11 authentication valid (Note the client will still need to complete 802.1x or WPA2 authentication if present).  Below is an example of a Disassociation frame: Note the same reason code in the "Wireless Management" field. Disassociation frames still have reason codes just like Deauthentication frames (0-39).

  Deauthentication  Type: 00 Subtype: 1100      Deauthentication frames are different from Disassociation frames as they will force a client to completely renegotiate the connection/ reset the 802.11 state machine. Deauthenticating a client can sometimes be useful in troubleshooting if you need to recreate a problem as the client will start the connection from scratch, allowing you to capture all frames from the beginning of the conversation.     Deauthentication frames can be sent broadcast or unicast from the AP or unicast by a client. The client's ability to send deauthentication frames means it is important to use protected management frames, so users on your network do not become victims of a deauthentication attack from a spoofed sender.     Below is a deauthentication frame from a packet capture:     There's not much to it. Note the reason code, there are reason codes 0-39 that will define why a client was deauthenticated. A ...