Optimize your WLANs for phones & Tablets (and Welcome Other Mobile Devices too)

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2 BRKEWN-2003 Optimize your WLANs for phones & Tablets (and Welcome Other Mobile Devices too) Jerome Henry, Principal Engineer, CCIEW#24750

3 Cisco Spark How Questions? Use Cisco Spark to communicate with the speaker after the session 1. Find this session in the Cisco Live Mobile App 2. Click Join the Discussion 3. Install Spark or go directly to the space 4. Enter messages/questions in the space cs.co/ciscolivebot#brkewn Cisco and/or its affiliates. All rights reserved. Cisco Public

4 Agenda Introduction Getting Connected build your first cell Probing and AP selection behavior Location Based services Random MAC address and location Optimizing Roaming Cell position and overlaps Optimizing Application Performances Dos and Don ts of WLC and ios tuning Conclusion

5 Ask Questions The first 2 questions will win a free full Real Time over Wireless Video course This Real Time over Wireless LiveLessons is a unique video course that provides the knowledge and details you need to create the best real time wireless experience for your organization. With more than twelve hours of video training, Real Time Over Wireless LiveLessons demonstrates the process of designing, deploying, configuring and troubleshooting Wi-Fi networks for real time application support. The videos cover the full range of topics you need to successfully deploy real time applications over Wi-Fi. This video series will help any network engineer successfully design wireless for real time applications and deploy common real time applications (Spark, Jabber, and Skype for Business) over Wi-Fi networks. I would rather have questions that can t be answered than answers that can t be questioned Richard Feynman BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 5

6 Building your First Cell

7 Imagine That You Are an IPhone You need to connect You do not know where the APs are You do not know what SSIDs are available You do not know what channels are available You do not know if the user is moving You are in the dark BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 7

8 Improved Scanning Behavior ios 8 and later only probe the broadcast (when not associated) Increased efficiency, increased security Do not set your SSIDs to no response to broadcast 2 probes at 20 ms interval on each channel If first request / reply collides, second will get the SSID 5 GHz scanned first (e.g. UNII-1, 3, then 2, 2e), then 2.4 GHz BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 8

9 DFS Channel Exceptions Scanned channels are based on country config All country channels are scanned (5 GHz and 2.4 GHz) Channels are DFS -> cannot probe directly Listen If frame detected channel is safe to use send probe requests You may wait up to 100 ms or 60 s! To avoid time waste, ios scans all other channels first, then E.g. (US, A Domain) 36, 40, 44, 48, 52, 56, 60, 64, 149, 153, 157, 161, 165, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11 Repeat 5 times, then scan 100, 104, 108, 112, 118, 120, 124, 128, 132, 136, 140 Refresh only every 6 scan cycles Your iphone / ipad may take up to one minute to detect an AP on channel UNII-1 UNII-2 UNII-2e UNII-3 BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 9

10 AP Arbitration Logic ios 9 and before: strongest signal over -70 dbm Load: 10% -50dBm - 63 dbm dBm Load: 100% AP1 A BAP2 Phone would choose AP B ios client selects AP2 Issue: strong signal does not equate to good AP BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 10

11 Getting Connected ios 10 and later: strongest signal and best throughput potential Load: 10% -60dBm -50dBm Load: 80% AP1 AP2 (APs with 100% load are also discarded) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 12

12 You are now Connected Your iphone / ipad will continue to probe: At regular intervals (327 seconds) And if the AP signal falls below -70 dbm ios probes the broadcast and your associated SSID Probe for awareness Roaming probe BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 13

13 What About non-ios Devices?

14 Determining Android Probing Behavior if You Have Some Time Android behavior depends on OS version (quite consistent between 4.4 and 6.0), but also NIC firmware and vendor tweaks: best is to test Keep in mind that a happy BYOD barely probes Example Samsung S7: when connected to a network, with data traffic and good signal (not mobile and/or mobile within good AP signal range), S7 probes with a 313, 1813 and 1430 second cycle BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 15

15 Android? Use Probe as Happiness Index Samsung S7 when idle and not associated (baseline) Interval between probes 131.3s cycle 66.6s after 6th Time BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 16

16 Determining Android Probing Behavior Try to determine when your BYOD gets to the edge of the cell (from its perspective): at that time, it will start probing repeatedly to find the next AP When at the edge of the cell, and idle (or moving with AP signal at low level), S5 settles to a 10.4 s cycle When you observe this kind of behavior change, you know that there is the edge of your cell Reached the edge of the cell, 10.4 s cycle BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 17

17 Determining Android Probing Behavior if You DO NOT Have Time Best case scenario: you have primarily on type of BYOD, and it is a major brand: its behavior might be documented here: Worst case scenario: you have all sorts of BYODs, or a minor brand: assume roaming when AP RSSI reaches -70 dbm (from the BYOD perspective). Compare the below to a test device: Model EIRP 2.4 GHz Worst* EIRP 5 GHz Iphone dbm 10.2 dbm Ipad dbm dbm Nexus dbm 11.1 dbm LG G dbm dbm Samsung S dbm dbm HTC One M dbm 13.8 dbm Nokia Lumia dbm 11.6 dbm PC (e.g. ASUS PCE- AC66) 22 dbm dbm * EIRP varies with sub-band, displaying worst of all sub-bands d I know I will get 6 db less at d Survival rule: 6 db difference halves the distance Received signal = X BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 18 2d Distance

18 Impact on Your Network Design 1. Make sure that at least one AP is available at > -70 dbm at entrance points 2. With ios 10, you can add APs for high density 3. Avoid DFS channels if low density With high density, DFS channels are okay, as active channels will be probed 40 MHz channels may force you to DFS - 70 dbm BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 20

19 Optimizing Roaming

20 How to Make ios Roam IOS does not scan if you move (no accelerometer trigger), until the AP signal falls below -70 dbm RSSI*. At that point phone scans and tries to roam. I want you to roam to AP 2 at point A - 70 dbm - 70 dbm Admin *(any packet from the AP, beacon or data is used; signal has to be received at less than -70 dbm for more than one second to trigger behavior) Point A (where my design says that the client should roam) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 31

21 How to Make ios Roam IOS does not scan if you move (no accelerometer trigger), until the AP signal falls below -70 dbm RSSI*. At that point phone scans and tries to roam. I want you to roam to AP 2 at point A - 70 dbm - 70 dbm AP1 Admin *(any packet from the AP, beacon or data is used; signal has to be received at less than -70 dbm for more than one second to trigger behavior) Point A (where my design says that the client should roam) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 32

22 How to Make ios Roam IOS does not scan if you move (no accelerometer trigger), until the AP signal falls below -70 dbm RSSI*. At that point phone scans and tries to roam. I want you to roam to AP 2 at point A - 70 dbm - 70 dbm AP2 AP1 Admin *(any packet from the AP, beacon or data is used; signal has to be received at less than -70 dbm for more than one second to trigger behavior) Point A (where my design says that the client should roam) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 33

23 How to Make ios Roam IOS does not scan if you move (no accelerometer trigger), until the AP signal falls below -70 dbm RSSI*. At that point phone scans and tries to roam. I want you to roam to AP 2 at point A AP signal is below 70 dbm, I need to roam to a better AP -> I start scanning - 70 dbm - 70 dbm AP2 AP1 Admin *(any packet from the AP, beacon or data is used; signal has to be received at less than -70 dbm for more than one second to trigger behavior) Point A (where my design says that the client should roam) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 34

24 The Authoritarian way - Optimized ( Smart ) Roaming Without Smart Roaming -85dB -80dB BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 35

25 The Authoritarian way - Optimized ( Smart ) Roaming Weak Wi-Fi Signal Without Smart Roaming -85dB -80dB BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 36

26 The Authoritarian way - Optimized ( Smart ) Roaming Without Smart Roaming -85dB -80dB Client Stickiness Causes Poor User Experience BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 37

27 The Authoritarian way - Optimized ( Smart ) Roaming Without Smart Roaming -85dB Overall Drop In Cell Performance -80dB Client Stickiness Causes Poor User Experience BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 38

28 The Authoritarian way - Optimized ( Smart ) Roaming Without Smart Roaming -85dB Cisco Smart Roaming -80dB Overall Drop In Cell Performance -80dB Client Stickiness Causes Poor User Experience 3G or 4G BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 39

29 The Authoritarian way - Optimized ( Smart ) Roaming Without Smart Roaming -85dB Cisco Smart Roaming -80dB Overall Drop In Cell Performance -80dB Client Stickiness Causes Poor User Experience Consistent User Experience 3G or 4G BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 40

30 The Authoritarian way - Optimized ( Smart ) Roaming Without Smart Roaming -85dB Cisco Smart Roaming -80dB -80dB Overall Drop In Cell Performance -80dB Client Stickiness Causes Poor User Experience Consistent User Experience 3G or 4G BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 41

31 The Authoritarian way - Optimized ( Smart ) Roaming Without Smart Roaming -85dB Cisco Smart Roaming -80dB -80dB Overall Drop In Cell Performance -80dB Client Stickiness Causes Poor User Experience Consistent User Experience 3G or 4G BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 42

32 The Authoritarian way - Optimized ( Smart ) Roaming Without Smart Roaming -85dB Cisco Smart Roaming -80dB -80dB Overall Drop In Cell Performance -80dB Client Stickiness Causes Poor User Experience Consistent User Experience 3G or 4G Efficient Cell Usage BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 43

33 ios and Aggressive Load balancing To steer clients to other available APs or bands, AP2 denies association No standards compliant reason for denial No information about neighboring Access Points If AP is the best signal iphone / ipad tries again After 5 attempts, SSID (not BSSID ) is blacklisted 1. Client attempts association with AP2 2. AP2 denies association Load: 10% -50dBm -30dBm Load: 100% Assoc Req AP1 Assoc Response (Status: Denied) AP2 Do not use Client Load Balancing with ios v can help BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 45

34 The Subtle Way: k (and v) Let s start with k What could my next AP be? Here are the best 6 for you Post-Association Steering: k neighbor list 4. Device loses WiFi connectivity with AP1 before re-establishing connection with AP2. (Nonseamless handover) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 47

35 The Subtle Way: k (and v) Let s start with k -70 dbm, I need to roam and scan: ch 36, 40, 44, 48, 52, 56, 60, 64, 149, 153, 157, 161, 165, then 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140 Total score: 6 seconds Post-Association Steering: -70 dbm, I need to roam and scan: scan shortlist ch 40, 48, 157. Found usable AP? yes -> roam Total score: 200 ms No usable Ap found? -> full scan 4. Device loses WiFi connectivity with AP1 before re-establishing connection with AP2. (Nonseamless handover) Without k With k BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 48

36 802.11v: Send your BYOD to the Next (Best) Cell k vs v BSS Transition Management What could my next AP be? Need to roam, what AP do you recommend? v Solicited request Here are the best 6 for you Try this one Your RSSI / rates are too low, roam to there instead k neighbor list Want to join your cell Nah, load too high, go there instead v Unsolicited Optimized Roaming request v Unsolicited request BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 50

37 802.11v: Cisco/Apple vs Other Guys We understand how ios thinks, other guys do not Need to roam, what AP do you recommend? Love it, thanks! Try this one Need to roam, what AP do you recommend? That is NOT a good AP! (ignore and full scan) Try this one BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 52

38 802.11r: Fast BSS Transition (AKA Fast Roaming) RADIUS RADIUS Full reauth Disassociation 4 way handshake -> new key MDIE PMKR1 Disassociation MDIE PMKR2 4 way handshake -> new key Standard WPA2 (802.1x) Score: up to 6 seconds r (FT) Score: less than 100 ms BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 53

39 Cisco-Apple Optimized Roaming Legacy client cannot join the same SSID where 11r is enabled k, v are on by default Non-Cisco-AP BRKEWN-2003 Cisco-AP 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 54

40 Cisco-Apple Optimized Roaming Legacy client cannot join the same SSID where 11r is enabled I recognize that you are an Apple device 11r is enabled for you k, v are on by default Non-Cisco-AP BRKEWN-2003 Cisco-AP 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 55

41 Cisco-Apple Optimized Roaming Legacy client cannot join the same SSID where 11r is enabled Legacy client that does not support 11r/k/v can join the same SSID I recognize that you are an Apple device 11r is enabled for you k, v are on by default Non-Cisco-AP BRKEWN-2003 Cisco-AP 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 56

42 Roaming Performance : 10x Better end-user Browsing and App Experience Time (s)* No QoS, No r/k/v QoS, r/k/v *Time Interval between last packet on previous AP, and first packet on next AP BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 57

43 An Example Cisco Bedfont Lakes Roaming points Support requests Wi-Fi issues during Video VoWi call Incident level Level 0 (productivity Crusher) - Call disconnected - Level 1 (Productivity Inhibitor) - Audio & video gaps - Level 2 (Minor Annoyance) - Audi glitch or light pixelization- (Before upgrade) Count over 1 week Total Determine coverage gaps 2. If coverage is satisfactory, look at SW config BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 58

44 An Example Cisco Bedfont Lakes Support requests Wi-Fi issues during Video VoWi call Incident level Level 0 (productivity Crusher) - Call disconnected - Level 1 (Productivity Inhibitor) - Audio & video gaps - Level 2 (Minor Annoyance) - Audi glitch or light pixelization- (Before upgrade) Count over 1 week (After upgrade) Count over 1 week Change (%) % % % Total % BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 59

45 An Example Cisco Bedfont Lakes Support requests Wi-Fi issues during Video VoWi call BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 60

46 What About the Other Clients? Some client support r (Enterprise Class), most do not support k / v r: search the Wi-Fi Alliance web site Voice Enterprise certified devices must support r BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 62

47 What About the Other Clients? Some client support r (Enterprise Class), most do not support k / v v: Mike Albano maintains a list of clients, with announced 11v support BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 63

48 What About the Other Clients? Mac OS Roaming Logic ( No 11v/k/r support Is 5 GHz -68 dbm or better? No Consider 2.4 GHz and 5 GHz networks Yes Target 5 GHz only Signal below -75 dbm? No Do not scan Yes Scan. New BSSID 12 db better? No Do not roam, scan in background Yes Pick 11ac 80 MHz Pick 11ac 40 MHz Pick 11ac 20 MHz Pick 11n 40 MHz Pick 11n 20 MHz Pick 11a (or g) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 64

49 Impact on your Network Design -70 dbm ch GHz vs 5 GHz issue AP1 power level 1 for 5 GHz AP1 power level 1 for 2.4 GHz Solution: make sure that AP power on 2.4 GHz is at least 2 levels below AP power on 5 GHz (e.g. 5 GHz -> level 3, 2.4 GHz -> level 5) RRM should do it for you if your design is right and RRM config correct AP1-70 dbm ch 36, -63 dbm ch Cisco and/or its affiliates. All rights reserved. Cisco Public 65

50 Impact on your Network Design Design your 5 GHz / 2.4 GHz overlap wisely: 2.4 GHz signal, at same distance from the AP, is commonly 7 db better than 5 GHz signal IOS is supposed to roam to next BSSID only if its signal is at least 8 db better than previous one (this in theory avoid the 5 GHz to 2.4 GHz poor roaming behavior) BUT measurement sensitivity uncertainty in mass silicon is 3 to 4 db* To limit roaming, limit the SSID to one band (5 GHz if possible). With dual-band SSIDs, expect frequent 5 GHz -> 2.4 GHz roams Iphone roams from 5 GHz to 2.4 GHz, same AP, same SSID AP - 70 dbm for 5 GHz, -61 dbm for 2.4 GHz, same SSID * This means that your Iphone can show -70 dbm for the AP, while my Iphone at exact same position can show between -66 and -74. Measure next day on your Iphone and you may also see anything between -66 and -74 BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 66

51 Impact on your Network Design If you can, design for 5 GHz only, and design optimized overlaps AP1 AP2 At the point where AP1 signal is -70 dbm, AP2 signal is -62 dbm Optimum edge: - 70 dbm 8/2dB (threshold) -4dB (fading/uncertainty) = -62 dbm BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 67

52 Strategically Position Your Transition APs At A the phone is connected to AP 1 A 1 B 2 At B the phone has AP 2 in the neighbor list, AP 3 has not yet been scanned due to the RF shadow caused by the elevator bank C 3 At C the phone needs to roam, but AP 2 is the only AP in the neighbor list The phone then needs to rescan and connect to AP B 54 Mbps is sent in 3.7 μs 200 B 24 Mbps is sent in 8.3 μs Rate shifting from 54 Mbps to 24 Mbps can waste 1100 μs BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 69

53 Strategically Position Your Transition APs A 1 B 2 At point A the phone is connected to AP 1 At point B the phone has AP 2 in the neighbor list as it was able to scan it while moving down the hall C At point C the phone needs to roam and successfully selects AP 2 The phone has sufficient time to scan for AP 3 ahead of time 3 BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 70

54 ios Analytics (Tell me about you)

55 Cisco-Apple partnership continues to deliver superior client experiences Phase 2 Phase 1 Application optimization on ios Application Optimization on MacOS Client-side Telemetry Optimized Roaming on ios BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 76

56 Cisco Apple Phase 2 : ios Analytics 1. Beacon Reporting to the Access Point by ios Client 2. Enhanced Dis-Association Reason to the Access Point by ios Client 3. ios Version information to the Access Point by ios Client Video demo : BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 77

57 How does the client see the Network How does the client see the network? The infrastructure does not know why this AP was chosen, because the infrastructure does not know how the client saw the network 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

58 How does the client see the Network How does the client see the network? The infrastructure does not know why this AP was chosen, because the infrastructure does not know how the client saw the network Why is this a problem? Because without that view, the infrastructure cannot help this (or other) client find the best AP How do Cisco and Apple solve this? Right after successful key-exchange during association, the ios 11 device sends to its AP an k beacon report ( Unsolicited mode ) This is how I see the network BSSID Channel Signal? bb:bb:cc:dd:ee:ff dbm cc:bb:cc:dd:ee:ff dbm dd:bb:cc:dd:ee:ff dbm 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

59 Where can I see this Scan report on WLC? Client detail page in the controller UI as Client Scan Report How can we use this neighbor map? To draw a super-accurate RF map of the floor, and help other clients roam When a new client enters the cell, and asks for a neighbor map, we can tailor the map to this client location! When another client needs to roam, we can suggest the best AP, seen from where the client sits! This is how I see the network BSSID Channel Signal bb:bb:cc:dd:ee:ff dbm cc:bb:cc:dd:ee:ff dbm dd:bb:cc:dd:ee:ff dbm 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

60 How does the Network see the device How does the network see the device? Usually as an ipad or iphone with DHCP and HTTP Device profiling When is this not enough? When we need to analyze device model and OS specific behaviors in the network? 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

61 How does the Network see the device How does the network see the device? Usually as an ipad or iphone with DHCP and HTTP Device profiling When is this not enough? When we need to analyze device model and OS specific behaviors in the network How do Cisco and Apple solve this? After association, the ios 11 client also tells us about itself. We can the correlate platform, OS to behavior at different points of time and space This is who I am? I am ios 11.0, iphone Cisco and/or its affiliates. All rights reserved. Cisco Public

62 How does the Network see the device How does the network see the device? Usually as an ipad or iphone with DHCP and HTTP Device profiling When is this not enough? When we need to analyze device model and OS specific behaviors in the network How do Cisco and Apple solve this? After association, the ios 11 client also tells us about itself. We can the correlate platform, OS to behavior at different points of time and space Where can I see this on WLC? Client summary and client detail page This is who I am? I am ios 11.0, iphone Cisco and/or its affiliates. All rights reserved. Cisco Public

63 How does the Network see the device How does the network see the device? Usually as an ipad or iphone with DHCP and HTTP Device profiling When is this not enough? When we need to analyze device model and OS specific behaviors in the network How do Cisco and Apple solve this? After association, the ios 11 client also tells us about itself. We can the correlate platform, OS to behavior at different points of time and space Where can I see this on WLC? Client summary and client detail page This is who I am? I am ios 11.0, iphone Cisco and/or its affiliates. All rights reserved. Cisco Public

64 Why did the Client go away? Do we know why client disassociated? When a client roams or disconnects, it sends a disassociation message. The AP does not always know why bad signal? Something else? Why is this a problem? Without knowing why a client is gone, we cannot help other clients in the same location (is this location okay? Is there a better AP there? Is there incompatibility in config at this location? 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

65 Why did the Client go away? Do we know why client disassociated? When a client roams or disconnects, it sends a disassociation message. The AP does not always know why bad signal? Something else? Why is this a problem? Without knowing why a client is gone, we cannot help other clients in the same location (is this location okay? Is there a better AP there? Is there incompatibility in config at this location? How do Cisco and Apple solve this? The Apple device sends a proprietary reason code Why I disassociated last Reason Code Reasons for disassociation DHCP Failed EAP Timed out 802.1x Failed Device Idle Captive Portal security Failed Decryption Failed WiFi Interface Disabled User-Triggered Disassoc Peer-Triggered Disassoc Beacon Loss 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

66 Why did the Client go away? Where can I see this Reason code on WLC? Client detail page in the controller UI How can we use this Reason Code? Help other clients in the same location if there is an RF issue Collect data to understand patterns (where clients go, etc) Why I disassociated last Reason Code Reasons for disassociation DHCP Failed EAP Timed out 802.1x Failed Device Idle Captive Portal security Failed Decryption Failed Interface Disabled User-Triggered Disassociation 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

67 For the first time ever, know how your iphone or ipad sees the wireless network Neighboring AP s Client Details Previous Disconnect Disassociation reason The Client s view of APs BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 89

68 DNAC Client Client profile - OS version and Product Type 2. Neighbor AP information 3. Disassociation reason and AP BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 90

69 DNA-C Assurance Apple Insights 1 2 Device Profile Wi-Fi Analytics 3 Assurance Client shares these details 1. iphone 7, ipad Pro 2. ios 11 Client shares these details 1. BSSID 2. RSSI 3. Channel # Client shares these details Error code for why did it previously disconnected Support per device-group Policies and Analytics Insights into the clients view of the network Provide clarity into the reliability of connectivity BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 91

70 DNAC Client Cisco and/or its affiliates. All rights reserved. Cisco Public

71 Deeper Dive on Cell Size and Power

72 Throughput (%) How Much Does Contention Affect Performance The Breaking Point Depends on How Many Clients You Have 120% 100% 80% 60% 40% 20% 0% 5% - 10% contention premium 10% - 30% 30% - 50% 50% - 60% Clients As more clients associate and transmit, WLAN contention increases for all clients. Retry attempts increase and each station spends more and more time in the waiting and listening state, driving down performance (source: IEEE /0351r2) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 94

73 Does Bandwidth Matter Anymore with ac Wave ac offers wide channels but is this good for voice? 160 MHz 80 MHz 80 MHz BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 95

74 Does Bandwidth Matter Anymore with ac Wave ac offers wide channels but is this good for voice? Wider channels offer higher throughput! 160 MHz 80 MHz 80 MHz BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 96

75 Does Bandwidth Matter Anymore with ac Wave ac offers wide channels but is this good for voice? Wider channels offer higher throughput! But is this good for voice and video??? 160 MHz 80 MHz 80 MHz BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 97

76 Smaller Channels are Better for Voice and Video (Implemented Through Dynamic Bandwidth Selection [DBS]) Better for data applications I just detected voice and video coming from a wide channel AP. Let s steer that client to a smaller channel for better performance Better for Voice and Video applications MHz 160 MHz 80 MHz 20 MHz BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 98

77 dbm Higher Power Does not Always Mean Better Signal RSSI Aim for: Noise level -92 dbm RSSI 67 dbm -> 25 db or better SNR Channel Utilization under 50%. Noise Level Time BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 99

78 dbm Higher Power Does not Always Mean Better Signal Blah blah blah RSSI You are a bit quiet Aim for: Noise level -92 dbm RSSI 67 dbm -> 25 db or better SNR Channel Utilization under 50%. Noise Level Time BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 100

79 dbm Higher Power Does not Always Mean Better Signal Blah blah blah RSSI You are a bit quiet Aim for: Noise level -92 dbm RSSI 67 dbm -> 25 db or better SNR Channel Utilization under 50%. Noise Level Time BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 101

80 dbm Higher Power Does not Always Mean Better Signal Blah blah blah RSSI You are a bit quiet Aim for: Noise level -92 dbm RSSI 67 dbm -> 25 db or better SNR Channel Utilization under 50%. Noise Level Time BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 102

81 dbm Higher Power Does not Always Mean Better Signal Is it better now? Blah blah blah RSSI You are a bit quiet Aim for: Noise level -92 dbm RSSI 67 dbm -> 25 db or better SNR Channel Utilization under 50%. Noise Level Time BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 103

82 dbm Higher Power Does not Always Mean Better Signal Is it better now? Blah blah blah RSSI You are a bit quiet Aim for: Noise level -92 dbm RSSI 67 dbm -> 25 db or better SNR Channel Utilization under 50%. Noise Level Time BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 104

83 dbm Higher Power Does not Always Mean Better Signal Is it better now? Blah blah blah RSSI You are a bit quiet Aim for: Noise level -92 dbm RSSI 67 dbm -> 25 db or better SNR Channel Utilization under 50%. Noise Level Time BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 105

84 Imagine This Scenario.... (based on an actual customer situation) ~ 120 ft Customer moved to first Wi-Fi only building (including voice and video) DISASTER! Wi-Fi was Terrible!! Investigation revealed all APs at max power (power level 1) Covering ~7500 sq. ft. per AP (2500 sq. ft. per AP is recommended) They needed 3x as many APs! BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 106

85 Modern Devices are Created Unequal Cisco 3700i AP (+4 dbi antenna on 2.4 GHz, +6 dbi antenna on 5 GHz) 23 dbm HTC M One Band Max Tx Power 2.4 GHz ISM 14.4 dbm UNII-1 14 dbm UNII dbm UNII-2e 12.1 dbm UNII dbm ISM (Ch 165) 12.8 dbm Source: FCC Disclaimer: antenna gain is not included BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 107

86 Power - client Side vs AP Side BYODs also use a small but low-performance antenna Example: Iphone 5 This is what the phone can actually send (out of the antenna) Band Max EIRP 2.4 GHz ISM 14.6 dbm UNII dbm UNII-2 12 dbm UNII-2e 11 dbm UNII-3 10 dbm ISM (Ch 165) 10 dbm Source: FCC BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 108

87 Power - client Side vs AP Side BYODs also use a small but low-performance antenna Example: Iphone 7 Band Gain (dbi) 2.4 GHz ISM 0.05 UNII UNII UNII-2e 0.04 This is what the phone can actually send (out of the antenna) Band Max Tx Power UNII ISM (Ch 165) 0.02 Source: FCC F Dipole cal. Certificate GHz ISM 15 dbm UNII-1 UNII-2 UNII-2e UNII-3 ISM (Ch 165) 14.8 dbm 13.3 dbm 10.8 dbm 11.8 dbm 11.8 dbm BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 109

88 Some Client Max EIRPs Model EIRP 2.4 GHz Worst* EIRP 5 GHz Iphone 6S 14.8 dbm 10.3 dbm Ipad dbm dbm Samsung S dbm dbm Samsung S4 tab dbm dbm Samsung S dbm dbm HTC One 14.4 dbm 13.8 dbm Nokia Lumia dbm 11.6 dbm ASUS PCE-AC66 22 dbm dbm * EIRP varies with sub-band, displaying worst of all sub-bands BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 110

89 If AP Signal is Strong, Client Uses High Data Rate Client power can be low, noise at the AP high, HW specs may be different This is the AP signal (at phone level) This is the phone signal (at AP level) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 111

90 Can Power Really Damage Cell Conditions? Bad design example: 12 dbm, dbm Based on Rx AP signal, BYOD thinks 54 Mbps rate is okay But client message is too weak, and AP does not ACK until rate falls to 12 mbps Each message takes 8 times more to be transmitted (including EIFS and retries) BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 112

91 So, what is the right Power? In short: half your worst client max power E.g. you design for 5 GHz, worst client max is at 11 dbm, set your AP power to 8 dbm Otherwise, you get this: BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 114

92 Hand and Phone Position Affect Signal Object in Signal Path Plasterboard wall Glass wall with metal frame Cinderblock wall Office window Metal door Metal door in brick wall Phone and body position Phone near field absorption Signal Attenuation Through Object 3 db 6 db 4 db 3 db 6 db 12 db 3-6 db Up to 15 db There can be a 20 db difference between these photos BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 115

93 Power and Roaming First Mandatory Data Rate is used for beacon transmission Can be used to modulate cell useful area But ios will roam if more than 20 beacons lost Beacon can be heard to here Signal can be detected to here Client will try to roam by here AP1 Signal can be demodulated to here BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 118

94 Hiding or not Hiding Urban Legend says that ios won t always associate to a hidden SSID It is a legend (unless your SSID does not respond to broadcast probes) BUT: loss of 20 beacons is loss of connection Without SSID field, beacon cannot be used BSSID is not enough Hiding SSID increases risks of disconnections Hiding SSID is not useful in most cases BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 121

95 Avoid Ping Pong Zones Client stays here Ping-pong effect occurs when a wireless client is at the edge of two cells and hops between them. BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 122

96 Impact on Your Network Design Set your AP power to 11 to 14 dbm When your AP signal is at -62 dbm / - 67 dbm on the phone, another AP should be in range Make sure that your first allowed rate is mandatory / beacon rate Don t hide the SSID Avoid Designs with sudden signal degradation (Ping Pong syndrome) Bad Outside space where people on a call pace back and forth Good BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 123

97 Real Time Applications Performances

98 Wireless Infrastructure and Clients Access mode 802.1Q Trunk 802.1Q Trunk AP WLAN Controller Ethernet Switch AP BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 136

99 Wireless Infrastructure and Clients Access mode 802.1Q Trunk 802.1Q Trunk AP WLAN Controller Ethernet Switch AP BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 137

100 Wireless Infrastructure and Clients Access mode 802.1Q Trunk 802.1Q Trunk AP WLAN Controller Ethernet Switch AP We do a lot here BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 138

101 Wireless Infrastructure and Clients Access mode 802.1Q Trunk 802.1Q Trunk AP WLAN Controller Ethernet Switch AP Not much we can do here We do a lot here BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 139

102 Fast lane Configuration Profiles A QoS configuration profile will ONLY be acted upon on an ios 10 client Uses standard Apple ios Profiling techniques (MDM, , Web-based) Profile lists whitelisted applications in a dictionary file Whitelisted applications are allowed to mark QoS (DSCP/UP) upstream Non-Whitelisted applications receive only BE/BK marking upstream Used in Combination with Cisco and Apple mutual detection 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public

103 Fast lane, Integrated Meraki Systems Manager (Cisco s Enterprise Mobility Management solution) can whitelist any app directly from the Apple App Store Quality of service made simple Fast lane Recap; Whitelisted applications get QoS Other applications are sent as best effort or background QoS settings are added to a wireless profile BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 141

104 Fast Lane only applies to Cisco-Apple Deployments QoS Profile or no QoS Profile QoS Profile QoS Profile is not considered Applications can only mark UP, not DSCP* If a Profile was received, All apps in White list Can mark QoS upstream Supports Fast lane Non-Cisco-AP Cisco-AP * DSCP can be marked with IP_TOS/IPv6_TCLASS when SO_NET_SERVICE_TYPE BRKEWN is Cisco best and/or effortits affiliates. All rights reserved. Cisco Public 142

105 Fast Lane enables network administrator to prioritize applications per your environment Supports Fast lane Admin can provision Apple IOS device with a QoS profile* Applications in whitelist get QoS marking** Other applications get BE/BK Supports Fast lane My profile for this environment: Minecraft = Real-timeinteractive Viber = BE My profile for this environment: Minecraft = BE Viber = Voice Supports Fast lane Supports Fast lane Cisco-AP *Without a profile, all applications are whitelisted by default in a Fast Lane cell BRKEWN-2003 **Fast Lane does NOT override apps QoS, it either allow the app QoS or apply BE Cisco-AP 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 143

106 Fastlane Who Does What Application Developer Network Administrator Mobile Device Manager End User Marks app flows appropriately based upon Apple APIs in ios 10 / Mac OS Makes new app version available on AppStore Upgrades Cisco WLAN Software to version 8.3.x Accepts most Cisco configuration defaults Enables Fastlane on target SSIDs (Optional) Creates and deploy an ios QoS profile to whitelist only mission-critical applications Downloads ios 10 (or above) on iphone and ipad, Mac OS (or above) from AppStore Accepts all defaults (Optional) Receives the QoS profile Cisco WLAN Network and Apple equipment with ios 10, Mac OS and above recognize each other; QOS marking is trusted end-to-end BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 144

107 Fast Lane delivers a reliable voice experience even in a congested environment In a congested environment, one voice packet is sent every 20 ms We measure the actual interval between voice packets in the upstream direction Interval (seconds) Packet average interval is 40 ms (not so good) Interval (seconds) Packet average interval is 20 ms (good) Many glitches, of up to 0.6 second (poor audio experience) Very few glitches, of up to 0.1 second (fair audio experience) No Fast Lane Capture time (seconds) Fast Lane BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 146

108 Summary

109 Summary Remember 70 dbm, 11 / 14 dbm ios 10 will grade APs based on performances roaming structure changes from ios 9 to ios 10 Avoid hidden SSIDs, DFS channels (except in HD), aggressive load balancing, smart roaming Think roaming path, position your APs so that view from the ceiling = view from the ground Enable 11k/r/v, DMS / BSS Max Idle Period, 5 GHz only SSIDs if you can Use AP power and placement for location-based services If you build for ios, other BYODs are likely to perform well too BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 169

110 You Did Your Best, But Good Design Cannot Compensate For Everything BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 170

111 Troubleshooting Tools Wireless Captures, RF Analysis, Configuration Analysis Wireless sniffer Omnipeek/Wireshark (multichannel, for roaming issues) Mac with OS X 10.6 and above, Windows 10 with Netmon 3.4 AP in Sniffer mode L1 analysis: SpectrumExpert WLCCA (WLC Configuration Analyzer) TAC support Cisco Prime Infrastructure for Historical view and «Client Troubleshooting tool» BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 171

112 Support Community BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 172

113 Cisco Spark How Questions? Use Cisco Spark to communicate with the speaker after the session 1. Find this session in the Cisco Live Mobile App 2. Click Join the Discussion 3. Install Spark or go directly to the space 4. Enter messages/questions in the space cs.co/ciscolivebot#brkewn Cisco and/or its affiliates. All rights reserved. Cisco Public

114 Please complete your Online Session Evaluations after each session Complete 4 Session Evaluations & the Overall Conference Evaluation (available from Thursday) to receive your Cisco Live T-shirt All surveys can be completed via the Cisco Live Mobile App or the Communication Stations Complete Your Online Session Evaluation Don t forget: Cisco Live sessions will be available for viewing on-demand after the event at Cisco and/or its affiliates. All rights reserved. Cisco Public

115 Continue Your Education Demos in the Cisco campus Walk-in Self-Paced Labs Tech Circle Meet the Engineer 1:1 meetings Related sessions BRKEWN Cisco and/or its affiliates. All rights reserved. Cisco Public 175

116 Thank you

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