Clear To Send: Wireless Network Engineering

There are authentication and encryption types any Wi-Fi professional should know about.. Meet Dave Benham Dave is a sharp Wireless Network Engineer and a great guy. He’s very knowledgeable in everything Wi-Fi and is cool to hang out with. This is one of the reasons we wanted you ask him some questions! Also, he has a great beard. Hear him on the episode! 802.11 Authentication and Encryption Types When it comes to Wi-Fi security, many people take a relaxed perspective. We wanted to help inform you on what is used in today’s networks with a little information on what’s to come in the future. Listen to the episode for the full discussion. Below is a short outline of what we talk about. Wi-Fi Authentication Open SSIDs Commonly used in public areas like coffee shops, airports, malls, restaurants, hotels, etc. It’s also used as a guest network at many businesses. With an open SSID, the device selects the network and just joins without any type of user authentication. You’re on the network! The problem with an open SSID is it is highly insecure. Pre-Shared Key (PSK) The PSK is the most widely used method of Wi-Fi Authentication. A password is configured for the SSID and each device wanting to connect must input the correct password. PSK is used everywhere from homes to even business networks. The biggest management overhead of a PSK is changing it when an employee leaves or a device is lost. When this happens, and the PSK needs to change, it must be changed on every single device using that Wi-Fi network. For this reason, many people don’t change their PSK often. 802.1X (WPA2-Enterprise) A way to keep your Wi-Fi network highly secure is to authenticate users and devices using 802.1X. It can be viewed as more complex to set up but nowadays there are services making it easier than ever to configure secure authentication. 802.1X is mainly used in the enterprise and is otherwise known as WPA2-Enterprise. Certificates may be needed either on the authentication server side and/or on the client side. Simultaneous Authentication of Equals (SAE) An improvement coming to Wi-Fi authentication is SAE. It strengthens the 4-way handshake which has been known to be insecure through a couple of methods that were revealed in 2018. It’s meant to protect PSK networks from offline dictionary attacks. Ask your vendor to implement this as soon as possible! Device Provisioning Protocol (DPP) The next iteration of WPS – which is a highly insecure method of connecting devices to the Wi-Fi network. DPP aims towards IoT devices or devices that don’t have a screen. It allows connecting of devices to a Wi-Fi network using a QR code or through NFC in a more secure manner. Wi-Fi Encryption None Obviously the most insecure method. It’s used with open SSIDs. A new method for protecting open SSIDs with no security will be Open Wireless Encryption (OWE). Bug your vendor to implement it ASAP! TKIP (WPA) A deprecated encryption method but still used in many environments. It’s a legacy encryption method used when CCMP is not supported on devices. Temporal Key Integrity Protocol using the RC4 Cipher (Rivest Cipher 4). It’s also limited to 54 Mbps. CCMP-AES (WPA2) Counter Mode with Cipher Block Chaining Message Authentication Code Protocol using the AES (Advanced Encryption Standards) Cipher. Implemented in WPA2 to improve on the weaker security methods prior to CCMP-AES. Used most of the time on modern Wi-Fi networks authenticated via PSK or 802.1X. Links & Resources * SemFio Networks’ Wi-Fi Security Timeline * Mobility Field Day 3...

The 4-Way Handshake is critical for secure wireless transmissions. Learn more about it in this episode. Alan Wang We met Alan at Cisco Live US 2018 in Orlando, FL. He was also the winner of our CLUS giveaway during the conference! Learn more about Alan, the network engineer, in this episode. CWS & CWT Bundle Giveaway Winners Congrats to Michael Velasco and Biruk Eshete for winning the book bundle! We’ll be reaching out to you via email. 4-Way Handshake If you recall back in episode 131, we spoke about the 802.11 Open System Authentication and Association. Following that episode, when using pre-shared key or 802.1X authentication you’ll come across the 4-way handshake. Wireless transmissions between the client and the AP need to be secure. We do that with four frame exchanges between a supplicant (client) and authenticator (AP). With a PSK network, the 4-way handshake occurs after the association frames. In an 802.1X network, the 4-way handshake occurs after the EAP authentication. The 4-way handshake is used to establish a pairwise transient key (PTK). It uses EAPOL-Key frames to form the 4-way handshake. Here’s a graphic to help describe the process. The messages between the supplicant and authenticator is as follows: Message 1: The authenticator sends an EAPOL-Key frame containing the ANonce for PTK generation. The supplicant will use this message to generate an SNonce and derive a PTK. Message 2: The supplicant sends an EAPOL-Key frame containing its SNonce, RSNE, and MIC. The supplicant derives a PTK. The MIC will be set to bit 1 and will be confirmed by the authenticator. The RSN element will be visible in this message. Message 3: The authenticator sends the message 3 EAPOL-Key frame and derives a PTK. The MIC is verified. Also important, the Group Temporal Key (GTK) is sent in message 3. ***In the episode I may have incorrectly called this the Group Transient Key. Message 4: The supplicant sends the 4th and last EAPOL-Key frame to the authenticator. It notifies the authenticator if the temporal keys were installed and the secure bit will be set. Download the PCAP file provided for this episode below in the Links & Resources section. Links and Resources * 4-way handshake PCAP * Mobility Field Day 3 home page * Mobility Field Day 3 – What to Expect

Let’s discuss the different 802.11 PHY types available for devices to use. Meet Glenn Cate Our featured wireless network engineer is Glenn Cate, CWNE #181. Catching up with Glenn at Cisco Live 2018 was great and we were able to get him talking about himself. Listen to the episode to hear a little bit about Glenn. 802.11 PHY Types The 802.11 Standard defines different PHY types. Includes the data rates supported by each PHY and what band they operate in. Data rates depend on the channel width and modulation used. Download the free 802.11 PHY Types Reference PDF In 1997, the first iteration of the standard was released. We call this 802.11 Prime. In this standard, the PHY type available used Direct Sequence Spread Spectrum (DSSS). It was only available in the 2.4 GHz spectrum using a 22 MHz wide channel. It offered 1 spatial stream and devices were able to use from 1 to 2 Mbps data rates. 802.11a was ratified in 2009 and operated in the 5 GHz spectrum. With this PHY, devices were able to use up to 54 Mbps data rates. Modulation used with this PHY type was Orthogonal Frequency Division Multiplexing (OFDM) and used a 20 MHz wide channel at 1 spatial stream. 802.11b, still operating in the 2.4 GHz spectrum used a modulation of High Rate DSSS (HR/DSSS) for this PHY type. It still used a 22 MHz wide channel width but offered data rates up 5.5 and 11 Mbps. To maintain backwards compatibility to DSSS but bring improvements to 2.4 GHz was the 802.11g PHY type. The new modulation used was Extended Rate Physical OFDM (ERP OFDM). The channel width changed to 20 MHz but still saw data rates up to 54 Mbps using 1 spatial stream. The biggest change to Wi-Fi came with the 802.11n PHY. It was dual-band and used the High Throughput (HT) modulation. It offered up to 600 Mbps data rates and introduced channel bonding to 40 MHz channel widths. Another improvement was the introduction of MIMO and 4 spatial streams. What we’re currently used to, as of the release of this episode, is the 802.11ac PHY type. Defined as Very High Throughput (VHT) and only operating in the 5 GHz spectrum, it introduced new channel bonding at 80 and 160 MHz channel widths. This increased channel width, along with 8 spatial streams, touts up to 6.9 Gbps data rates. But don’t hold your breath. Next up, not ratified yet as of the time of this published episode, is 802.11ax PHY type with modulation scheme of High Efficiency (HE). This brings increased efficiency in the 2.4 GHz and 5 GHz spectrum. Specifying, in this PHY type, is 1024 QAM and up to 9.6 Gbps data rates. We shall see what this brings to the real world. Links and Resources * Free 802.11 PHY Type Table * 802.11 Authentication and Association * RF Characteristics

Recorded at Cisco Live 2018 in Orlando, FL, we speak to Christian Gauer about Wi-Fi location-based analytics. Meet Greg Skeene Our featured wireless engineer for this episode is Greg Skeene. He’s a listener of the show and we finally met up during a meetup at Cisco Live. Listen to the episode to hear him answer François’ 10 questions. Location-Based Analytics This episode was recorded at Cisco Live 2018 in the Podcast Domain. Our guest is Christian Gauer, a TME in Cisco focused on location-based analytics. We’re new to location-based analytics so we wanted to know more about it. Especially with the increased amount of IoT devices coming on the network. Can we use that data to make business decisions? What are some of the expectations for location-based analytics? We can expect to do way-finding, locating a device, using an app to locate yourself to draw line on the map of where to go. Location is calculated by a Cisco CMX box. Data going into CMX needs to be accurate. This means design will be critical. APs should be mounted on the ceiling up to 20 feet high. Multi-trangulation is used in measuring distance-based on RSSI. More accurate measurements is done with angle of arrival. Multi-trangulation needs more than 3 APs for higher accuracy. More than just triangulation. Why 3 APs minimum? Because of triangulation. With wireless location, a device needs to be inside context of APs. For location, start at the perimeter of the walls. But why go into location-based analytics? Everyone wants to know whats going on. Top use cases – retail wants to know what’s going on in a shop and how much time customers are spending time in the shop and which section. An airport may want to know what’s going on with security, how much time people are spending there, or maybe there are too many people crowding at the gate. Take a coffee chain with many locations into consideration. They offer free Wi-Fi. Device get connected and now the coffee chain can track who is connecting to their Wi-Fi network. But how many APs does a coffee shop need? Maybe need 1 or 2 APs for coverage. What kind of info can you get out of it? Is it important where someone sits, maybe not? It can be difficult differentiating someone sitting next to another.. or lining up. Presence provides detection of customer which means you can find out who is stopping by multiple shops. This is how you identify return visitors and measure dwell time. Other methods of using location-based analytics includes having an idea of how busy the store is for staff planning or how long it takes customers to get cup of coffee. But a store needs to ask the question from the customer point of view, why should I connect to the Wi-Fi? There has to be an offer. Listen to the episode for more details! Links & Resources * Arista acquires Mojo Networks * Our episode with the CEO of Mojo Networks * New attack on WPA/WPA2 * CWS and CWT Giveaway – Fill out form on this page * CLUS Sessions related to Location-Based Analytics * Connected Mobile Experience (CMX) – BRKEWN-2012 *

What frame exchanges are part of a device joining an SSID? CWS & CWT Book Giveaway We’re raffling off a two bundles of the CWS & CWT books from CWNP. Two winners will get a copy of each book. If you’re getting into Wi-Fi or would like to know the fundamentals so you can sell Wi-Fi then this is a good resource to use. All you have to do is fill out the form below. Meet Dustin Johnson Our feature wireless engineer for this episode is Dustin Johnson. We ran into him at Cisco Live by accident and he happens to be a listener of the show! Listen to the episode to hear him answer François’ 10 questions. 802.11 Authentication and Association How does the station (STA) and access point agree to this connection? We’re going to break down the steps and the frames that are part of a STA connecting to an access point. We have one STA connecting to an open SSID. The summary of it all is as follows: * STA is unauthenticated and unassociated * STA becomes authenticated and unassociated * STA becomes authenticated and associated * STA clears security requirements such as 802.1X, if required Beacon/Probe The STA begins the process by performing a passive or active scan. In passive mode, the STA is listening for beacons from an access point. The beacon frame contains the BSSID which is the MAC address of the radio sourcing from the access point. The beacon frame is a type of management frame defined in 802.11-2016. It includes capability information and parameters. A probe is sourced from the STA requesting to join a wireless network. This is a probe request management frame. The probe is responded by an access point using a probe response management frame. Authentication The probing/scanning phase is part of the unauthenticated and unassociated step. The STA has not authenticated with the access point and also is not associated with the access point. Think of authentication as plugging a computer into a port on a switch. The STA must be authenticated to the access point before it is associated. It sounds backwards. These are the two states in this phase and it must be done in this order. * Unauthenticated or authenticated. * Unassociated or associated. To begin the Authentication step, the STA sends an Authentication wireless management frame to the access point. The access point responds with an Acknowledgement frame. The access point will acknowledge the Authentication frame from the STA and upon successful authentication, the access point will send an authentication frame to the STA with an Authentication Sequence with a State of 2, for success. Access point sends an Authentication frame with a state of 2, for Successful. Association Once the STA is authenticated to the access point, the next step is to become Associated. The Association occurs after the Shared Key Authentication or Open System Authentication Algorithm. There cannot be a STA that is Associated but not Authenticated. If the STA fails Authentication, it does not move to Association. After the the access point sends an Acknowledgement to the STA’s Authentication Response, the STA sends an Association Request. The Association Request is Acknowledged by the access point which then sends an Association Response frame to the STA. If the association is successful, the access point’s Association Response frame will contain a Status code: Successful. The details within an Association Response include: * Capabilities Information such as

Get your basics of Wi-Fi starting with RF characteristics. Before we get into RF characteristics, we want to introduce our series of interviews we did at Cisco Live 2018. We interviewed many wireless engineers to get to know them better. We ask ten questions, we get ten answers. So meet Jason Beshara. We introduce him starting at minute 7:06. RF Characteristics RF is Radio frequency. When talking about Wi-Fi we are referring to unlicensed radio frequency in the 2.4 GHz and 5 GHz spectrum. Wi-Fi is not the only radio frequency in the air. There are other frequencies such as microwave and AM/FM radio. A carrier signal is used to take AC signal from the radio to turn it into a waveform. Information is transmitted from the antenna on the carrier signal as an electromagnetic wave. Modulation is done to modify the signal to create the carrier signal which will carry the 1s and 0s. When defining a wave, we talk about its wavelength. It is the distance between two identical points in a wave. Higher frequencies have a shorter wavelength thus they get attenuated faster. Lower frequencies have longer wavelengths. Another characteristic of an RF wave is its amplitude. This is the power of the wave or signal strength from the transmitting device. As signal is propagated through the air it is received at a lower amplitude. Higher amplitude increases the chance of the receiver successfully demodulating the signal. Frequency is another characteristic. This is the interval in which the wave repeats or oscillates. A 2.4 GHz signal repeats 2.4 Billion cycles per minute. Higher frequencies have shorter wavelengths. Then we have phase. Phase compares two RF waves. If a device receives two copies of an RF wave, the phase can determine whether it is positive or negative. To make multiple RF waves positive, they would need to be in-phase. This would strengthen the wave or increase the amplitude thus increasing the ability to demodulate signals. If received signals are out-of-phase, the signals may cancel each other out if 180 degrees out of phase. How can RF be affected in the real world? We talk about some of the ways below and in the episode: Reflection When a signal bounces off an object such as a mirror or metal. It’s like aiming a flashlight onto a mirror and the signal bounces in a different direction. Absorption This occurs when RF goes through material such as a wall. Absorption will weaken a signal (attenuate). Material such as dry wall, concrete, doors, windows, etc. Each material has different attenuation values. Shine a flashlight through a white sheet and some signal is absorbed by the material. Refraction When signal goes through a different medium, such as water, the signal is bent. Take a glass of water, as an example, and notice how light shining through one side is bent leaving the other side. Scatter Signal that hits an uneven surface and reflected in multiple directions is scatter. Think of a disco ball or chain link fence. As signal hits these surfaces it is reflected everywhere. Diffraction Diffraction occurs when a signal goes around an object. Like a rock in the middle of a flowing river. Water flows along the sides of the rock. Directly behind the rock there is less of a current from the stream. With Wi-Fi, signal may not go through a concrete pillar but it will go around it. But a device directly behind that pillar will be in an RF dead zone or RF shadow. Attenuation Earlier we talked about absorption. Attenuation is when there is a decrease in amplitude and the signal is weakened or there is a loss of signal. This can commonly happen through absorption. Multipath Multipath is a result of scatter and reflection. A device can receive multiple copies of the same signal through multipath. Links and Resources *

Recorded at Cisco Live 2018 in Orlando, Florida. We speak to Mike Geller and Pramod Nair about 5G technology and what Wi-Fi professionals would know about. 5G Technology We’ve been hearing a lot about 5G lately. But do many of you what is involved with 5G? We just know it’s the next number up from 4G

We’re diving into a world where businesses and Wi-Fi network engineers have full control over their Wi-Fi infrastructure through White Box Wi-Fi. This episode is sponsored by Mojo Networks White Box Wi-Fi Rick Wilmer, CEO of Mojo Networks, got into the wireless industry through a CPE and core router company. He saw wireless networking being the next big technology. We start by asking him, what is cognitive Wi-Fi? It’s collecting a mass amount of data from a network. They use the data to predict what the network is going to do next. If that’s going to be a negative user experience, going to try to remediate that problem fast enough before a user knows they’re going to have a problem. Cognitive Wi-Fi works better with more data, thus Big Data. Machine learning is applied to that data to automatically remediate issues related to end user experience. What is the biggest value of white box Wi-Fi? It drives cost of enterprise Wi-Fi down. As the cost of the solution goes down, volume goes up. Mojo Networks is about to ship their 500,000th access point. With the more APs out there in production, the more it feeds Mojo Networks’ big data. Rick Wilmer says functionality and design is moving to the chipset vendors. Hyper scale companies are scaling out large data centers with compute but in their own way without relying on big vendors. That’s how Rick Wilmer found his way to the Open Compute Project (OCP). OCP drives open standards around hardware which drives the trend of applying it to Wi-Fi. Nothing new is invented. Just as applying what was done to servers and switches but now into Wi-Fi. This focuses Mojo Networks towards developing more of the software side. If the AP is defined by the chipset and all the chipsets are largely coming from Broadcom and Qualcomm, that hardware platform is essentially going to be the same as far as core functionality. Does that mean hardware doesn’t matter? Hardware is still important. It is important in a design and manufacturing stand point. But it’s driven by sophisticated original design manufacturers (ODMs). Which verticals can take advantage of white box Wi-Fi? Wilmer says, higher education, enterprise, retail, and many more. What’s driving the need for white box Wi-Fi? Generation 1 of the white box Wi-Fi is making APs available to customers at a price they come out of the factory. There’s no mark up or margin. Hardware comes from one vendor and software comes from someone else. It’s a disaggregation model but Mojo Networks obfuscates the process for the customer. Generation 2 white box Wi-Fi is when the industry gets to a point where APs from different Wi-Fi vendors interoperate. Think about a light bulb. Any light bulb from any store can plug in and work. “I can buy any brand of light bulb from any store, bring it home, plug it in, and it’s going to do what I expect it to do, which is light up my room. Wouldn’t it be amazing for the customer if access points worked that way.” – Rick Wilmer What is the impact to firmware support. Wilmer says APs have been qualified to work with Mojo Networks cloud. Software has been certified with hardware, such as Edgecore access points. We will see innovation moving away from hardware and into Cognitive Wi-Fi. What are the basic requirements of a white box AP and what are the basic features we can expect to see? Wilmer says we will see full parity on the Mojo Cloud. This has already been put into production with Edgecore and Mojo Networks APs at the Open Compute Summit which was held in the San Jose Convention Center. Mojo Networks provided the guest Wi-Fi for the summit. Edge Core APs were running Mojo Networks’ code.

Ensuring the stadium Wi-Fi implementation goes according to the design. Stadium Wi-Fi Implementation Chris Reed joins the show to follow up on his stadium Wi-Fi design episode to discuss the implementation portion. He joined us back on Episode 123 where he went into the design of Wi-Fi within large public venues or stadiums. A wireless network is more than just Wi-Fi. Improperly sized, configured, or issues will cause “The Wi-Fi isn’t working” Doesn’t matter if you don’t own these, understand their layout, and ask the questions to make sure it’s not going to bite you. Understand the associated network functions that go into a proper network implementation, beyond the Wi-Fi. Things such as Internet bandwidth, wired infrastructure, DNS, and DHCP. Documentation is always a critical piece of the design and implementation. You should have the output from your design software to hand off and to use for your validation. This includes some sort of visualization of different install models for cable installers. Walkthroughs are a must for stadium Wi-Fi implementation. Walk through with your installer, every space. This is their chance to speak up, ask questions, and for you to get things clarified. It’s up to you to make sure installers are following your standards. There are lots of bad Wi-Fi engineers, and these installers may have been working with them. You can find these at badfi.com. Run through the “why?” of your design. Why is it important the angle is right, why is it important they aren’t near the DAS antenna? And also very important, where are the antenna leads supposed to be connected to? When it comes to configuration, are you still using the GUI? Let’s assume 1,400 APs, and there are 5 settings / functions to configure – name, description, channel, antennas, power. Assume a 1% error rate (you’re pretty good at this). You’re going to get 70 configuration settings wrong Oh, and now the customer wants to change the naming convention. Have fun

We took Anders Nilsson away from a party during Cisco Live and asked him to talk about Eduroam. Eduroam Anders Nilsson joins us on the show to discuss the basics of eduroam, how it works, and why higher education institutions decide to deploy the eduroam SSID on their campus. Anders is from Sweden and you may know him through the Wi-Fi Moose. https://twitter.com/HerrNilsson2/status/1007630629272457216 Anders does work for the Swedish education network and is technically responsible for eduroam in Sweden. That makes him today’s subject matter expert for this topic. If you’re from a higher education institute you may be familiar with eduroam already. Or maybe you’re thinking about deploying eduroam or you don’t fully understand how it works. Anders provides a thorough introduction to eduroam which was started around 2003 in the Netherlands. The goal was to provide a better way for guest students at a visiting university to access Wi-Fi. In it’s early days, eduroam was implemented as an Open SSID with an access list that allowed VPN only. They quickly realized this method wouldn’t scale very well and went for the 802.1X solution instead. eduroam is WPA2 Enterprise based with a federation of RADIUS servers. This means an institution will peer its RADIUS server(s) to the eduroam federation RADIUS servers. When a visiting user wants to join the eduroam SSID but authenticate back to the home RADIUS servers, the local institution will forward the authentication requests up the eduroam chain. This allows for a seamless, convenient connection for the global academic community by using a single SSID, eduroam, at any participating institution. In the old days, a visiting user had to get ahold of the local IT department in order to gain access or use a visitor SSID. Since eduroam is implemented using WPA2 Enterprise, it is strongly suggested to start with using EAP-TLS. Although, other EAP methods are allowed to be used, the table below features the common EAP types deployed with eduroam. EAP-Type Native Supplicant Support Pros Cons EAP-TLS Windows (XP, Vista, 7), Mac OS X, Linux, iOS (iPhone, iPod Touch, iPad), Android (v1.6+) • Validates client as well as infrastructure • Reduced risk of being Phished • Blocking user access is via certificate revocation • PKI infrastructure is required • Users must configure supplicant to use certificate* • Identity may be exposed in TLS exchange depending on contents of certificate EAP-TTLS Windows (8, 10), Mac OS X, Linux, iOS (iPhone, iPod Touch, iPad), Android (v1.6+) • No native supplicant support on Microsoft Windows XP or 7 • Potential for Man-in-the-Middle attacks* EAP-PEAP Windows (XP, Vista, 7), Mac OS X, Linux, iOS (iPhone, iPod Touch, iPad), Android (v1.6+) • Works on many platforms • Potential for Man-in-the-Middle attacks* • Identity may be exposed during Phase-1 of exchange Links and Resources Follow Anders on Twitter – @HerrNilsson2 Learn more about eduroam Read the eduroam FAQ

We take a look at what resources are available to capture frames on Windows OS. 802.11 Frame Captures on Windows Back in episode 121, we spoke highly of Macbook Pros being perfect tools for wireless frame captures. But not everyone has a Macbook Pro. Even I still have a Windows laptop and need to do frame captures on that every once and a while. In this episode, we outline some of the resources we use for capturing frames on Windows OS. Both free and paid versions depending on how you’re trying to capture frames and how quickly you’re trying to accomplish the task. Budgets will vary widely with each resource so check for the most updated pricing online. Acrylic Wi-Fi Professional You can try out Acrylic Wi-Fi with a trial version free for 4 days. As of June 2018, a license is $39.95 one time fee (or $19.95 for 1 year). It has a built in 802.11 packet capture tool without requiring additional hardware. But it only captures beacon frames if your Wi-Fi NIC does not support monitor mode. The NDIS driver must be installed so your built in Wi-Fi NIC can be used in monitor mode.  If you want, you can use an external adapter to perform the capture. Acrylic recommends the following: * D-Link DWA-182 Revision A1 * Netgear A6200 * Asus USB-AC53 * List of compatible Wi-Fi NICs By default, it will be channel hopping. So don’t forget to set the channel on which you want to scan. We strongly recommend using a Riverbed AirPcap card if you are going to do anything professional. Some of the packet capture features include: * Display the Packet Tree view including the details of the Radio Tap Header * Displays the Hex and Binary view of the packet * You can export the frames into a pcap file and analyze them with another tool (Wireshark) * Integration with Wireshark * 802.11ac not there with AirPcap Nx Other Features: * Wi-Fi Scanner * Show Retry Rate when set to monitor mode * Displays the SSID detected (including the hidden SSID) * Displays some beacon details * Script editor built-in * Reports * Inventory Links: * https://www.acrylicwifi.com/en/wlan-wifi-wireless-network-software-tools/wifi-analyzer-acrylic-professional/ * https://www.youtube.com/watch?v=buMJ9NDCsGA * https://www.acrylicwifi.com/en/blog/how-to-capture-wifi-traffic-using-wireshark-on-windows/ Microsoft Network Monitor This tool is free to use with your operating system. You can download the application from Microsoft and check out a full tutorial. You can find a Video Tutorial easily on YouTube.

Clear To Send is headed to Cisco Live Orlando. Cisco Live Orlando One of the largest conferences is headed back to the East Coast – in Orlando, Florida. If you know anything about Cisco Live then you know there are a plethora of sessions to select from. But we’re passionate about Wi-Fi which is what we’re going to highlight in a list here. These session’s we’re interested in attending and the ones you should keep an eye on. Even if you aren’t attending, most of the sessions will be made available weeks after the conference is finished. #CLUS Giveaway Participate in our Clear To Send Giveaway. Because François and Rowell are joining together for the first time for CTS episodes, we wanted to give back to our listeners. We’re offering two giveaways, a Ventev Mobile Device Accessory kit ($300 value!) and a Cisco Press book of the winner’s choice. Here’s how to enter: * Fill out the form below (United States entries only) * For an extra entry, find Rowell or François at CLUS, take a photo with one or both of them, and share it by tagging @cleartosend on Twitter. Contest is over! Live Recordings Come watch François and Rowell do a live recording of a Clear To Send episode. There are a total of three recordings: * Monday June 11th @ 1PM– WiFi Analytics with Christian Gauer at the Podcast Domain Booth #1059 in World of Solutions * Tuesday June 12th – Cisco Live WiFi Meetup at 6:30pm – RSVP and Location here * Wednesday June 13th at 4pm – 5G with Mike Geller at the Podcast Domain Booth #1059 in World of Solutions Wireless Session Quick List Monday June 11 * Securely Designing Your Wireless LAN for Threat Mitigation, Policy and BYOD * Defining Your 5G Architecture * Smarter, End-to-End Network and Application Performance Troubleshooting with Meraki * Deploying Fixed Wireless Access using 5G Technology Tuesday June 12 * DNA Wireless Assurance: Isolate problems for faster troubleshooting * Cisco SD-Access Wireless Integration Wednesday June 13 * High Density, High Capacity Network Design with Cisco Meraki Wireless * Get Greater Wireless Value with Cisco Indoor Location Services * Understanding RF Fundamentals and the Radio Design for 11ac Wireless Networks * Optimize your WLANs for Iphones and iPads (and welcome othe...

François Vergès and Chris Reed join forces on Clear To Send to talk about design principles of stadium Wi-Fi.  Designing Stadium Wi-Fi What are important considerations when designing Wi-Fi for very high density environment such as stadium? Of course the tools come to mind such as Andrew Von Nagy’s Capacity Planner and Ekahau Site Survey Pro. In the initial design, there are different types spaces in stadiums to consider such as bowl, concourse, suites, office space, and event space. The details are discussed in the episode. Fundamentals are always important. But they are often missed in many deployments. Things such as getting the AP as close to the client as possible, minimizing co-channel contention, transmit power, attenuation, etc. Another consideration, but often difficult to plan for in stadiums, are client devices. An challenging aspect of stadium Wi-Fi design is AP placement. There are different ways to approach this such as overhead, railing, and underseat. Which one is best for the design and what the pros and cons. Links & Resources * Capacity Planner * Designing Very High Density Best Practices & Test Results * Superbowl 50 Analytics * Aruba Very High Density 802.11ac Networks Validated Reference Design * BEI Networks * @TheCMReed

Wi-Fi Alliance EasyMesh certification is meant to bring interoperability between vendors for mesh networking. Wi-Fi Alliance EasyMesh Mesh networking helps bring coverage in homes where one access point can’t quite do it. The Wi-Fi Alliance EasyMesh enables interoperability across access points from different vendors. The term given to an access point is Multi-AP. The Multi-AP has two logical entities: * One Multi-AP controller * One or ore Multi-AP agents The Multi-AP agents report measurements and capability data to the Multi-AP controller. A controller interface is defined between the Multi-AP agents and the controller and/or between agents. Having a controller in the home is an interesting idea coming from the enterprise space. Essentially, this would be located in the residential gateway. The controller will manage roaming and load balancing between APs. The method in which Multi-APs join the controller will be a mandatory method of Push Button Configuration (PBC). There is also a backhaul station on-boarding procedure via AP-Autoconfig for discovery. Network Operations There are various configurations managed from the Multi-AP Controller: Capability Report Multi-AP Agents report capabilities to the controller such as the number of radios, channel width supported, PHY protocol supported.  Channel Selection Channel configuration is performed by the controller. By default the maximum Tx Power is used but the controller can decide to lower it down to improve system signal conditions. The controller sends a Channel Preference Query message to each Agent. The EasyMesh specification does state DFS support so we’ll see many more channels available in the home. Link Metric Collection Client devices can convey link metric information related to the network. Agents also leverage 802.11k beacon report measurements to report metrics about the quality of the links between the agent and the clients. Client Steering The controller sends control messages to the agents to steer clients. Client supporting 802.11v BSS Transition Management will experience faster transitions. Optimizing Connection Between Agents Controller select the best path to connect the agents together. Thoughts It will be interesting to see if vendors will get together on this specification to improve home networking. Wi-Fi Alliance EasyMesh looks aimed for ISPs to provide home mesh networking for their customers. With a gateway from an ISP, they can control the other APs in the home. This helps them reduce the number of customer calls about poor Wi-Fi and reduces the number of truck rolls. We can see ISPs partnering with specific AP vendors which are EasyMesh certified to sell a solution to the customer. But without more spectrum (6 GHz) and 802.11ax, we won’t see much improvement in home mesh network in environments where it is highly dense. Links and Resources * Wi-Fi Alliance EasyMesh * EasyMesh Specification

Capturing wireless frames is a must know skill for any Wi-Fi network engineer. Capturing Wireless Frames with a Mac The Macbook Pro is an excellent tool for capturing wireless frames. The built-in wireless adapter can be used to sniff wireless frames in the air. As I like to say, the best troubleshooting tool you can have is the one that’s with you. Since I have my Mac with me all the time I tend to capture frames wherever I go. There are many pros with capturing frames. It’s a great way to learn how Wi-Fi works. This is how I got started. Understanding how Wi-Fi communication works through frame captures gives you an upper-hand. One example is learning about the 802.11 State Machine. When it comes to troubleshooting complicated issues, frames don’t lie. Not too long ago, my laptop had a difficult time connecting to public Wi-Fi. It frustrated me so much I decided to capture some frames. Within minutes I found out why. Just take a look at the screenshot below. Tools * Macbook Pro * Airtool * Metageek Profile * Metageek Profile for Wireshark * Mojo Packets How To Capture Frames * Install Wireshark * Install the Metageek Profile * Unzip the file * Copy directory to /Users/user/.config/wireshark/profiles/ * Enable the profile in Wireshark by clicking on the bottom right of the open application. See screenshot below. * * Install Airtool * Select channel & channel width to capture on * * Start the capture and stop after a short time * * Analyze with Wireshark or Mojo Packets Links and Resources * Airtool * Wireshark * Mojo Packets * Metageek Wireshark Profile * Automating Wi-Fi Packet Analysis with Pyshark