#CLUS Wireless Best Practices for Next-gen Workspace Aparajita Sood, Technical Marketing Engineer BRKEWN-2670 #CLUS Cisco Webex Teams Questions? Use Cisco Webex Teams (formerly Cisco Spark) to chat with the speaker after the session How 1 Find this session in the Cisco Events App 2 Click “Join the Discussion” 3 Install Webex Teams or go directly to the team space 4 Enter messages/questions in the team space Webex Teams will be moderated cs.co/ciscolivebot#BRKEWN-2670 by the speaker until June 18, 2018. #CLUS © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 3 #CLUS © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public The Enterprise Becomes Social Customer & Employee Collaboration Work Styles Have Evolved Work anytime from anywhere “Work is a thing you do, not a place you go to” Video Becomes Pervasive Across All Devices Any Time, Any Place What Do You Consider First? #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 6 Agenda Design Provision Optimize Assurance • Designing for Performance and Resiliency • Provisioning with Best Practices • Optimizing RF and Security • Assurance and Analytics #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 7 Deployment Lifecycle The Bigger Picture Design Provision Optimize Assurance Planning Easy Setup Operate Analytics • Mobility Design • Express Setup • Optimizing RF • Workspace Guides • Plug and Play • Prioritize Apps Analytics • Data Sheets • RF Planner • Best Practices • Segment and • Monitoring and • Site Survey Secure Real time Diagnostics #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 8 Next-Gen Office Design Goals Designing for RF Coverage and Performance #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 9 Media Access: Wi-Fi Networks are not Deterministic! (like a teacher in a class) More devices in cell Greater contention Increased risk of collisions #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 10 How Much Does Contention Affect Performance The Breaking Point Depends on How Many Clients You Have 120% 100% As more clients associate and transmit, WLAN contention increases for all clients. 80% 5% - 10% contention 60% premium 10% - Throughput (%) Throughput 40% 30% 30% - 20% 50% Retry attempts increase and each station spends more and more time in 50% - 60% the “waiting and listening” state, 0% driving down performance 1 5 10 25 50 75 100 Clients (source: IEEE 802.11-15/0351r2) #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 11 Design for Density, not Coverage 3.2 Mbps cell edge 72.5 Mbps cell edge #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 12 People only use one real time application at a time Application – By Use Throughput – Nominal Case 1. Check the bandwidth of each expected Web - Casual 500 Kbps applications in your network Web - Instructional 1 Mbps 2. Multiply by number of users of that Audio - Casual 100 Kbps application in the cell: Audio - instructional 1 Mbps Video - Casual 1 Mbps Video - Instructional 2-4 Mbps This is the bandwidth you need at the edge Printing 1 Mbps of the cell File Sharing - Casual 1 Mbps File Sharing - Instructional 2-8 Mbps Online Testing 2-4 Mbps Device Backups 10-50 Mbps #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 13 An Example – Identifying the BW Needs in a Cell • Skype 4 Business / Lync (Up and Down): Call type Audio Audio HD Video Video HD Typical 51Kbps 86Kbps 190kbps 2.5 Mbps Bandwidth • A few other examples: • Jabber audio (G.711) ~100 kbps, Jabber video (HQ) ~750 kbps • Facetime (video, iPhone 4S): 400 Kbps, (audio) 32 kbps • Viber, Skype (video) 130 kbps, (audio) 30 kbps • Netflix (video), from 600 kbps (low quality) to 10 Mbps (3D HD), average 2.2 Mbps #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 14 I need ~12 Mbps Real Life Example throughput everywhere in the cell . therefore I need it here • Density studies show active 12 users / cell on average (-67dBm) • Expected 2 HD video calls (Skype type) • 5 audio calls • Other users may browse • Let’s do the math: • 2 HD video calls = 2.5 Mbps x 2 x 2 ways = 10 Mbps AP • 5 audio calls… mmm what application? • Maybe SfB 51 kbps x 5 x 2 ways = 510 kbps • Others are browsing (5 people) = 250 kbps / user = 1.2 Mbps • Total = ~12 Mbps needed #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 15 Cell Shape and Cell Size • Your cell shape depends on the antenna you use: Omni • Directional Directional Same areas • Omnidirectional • The cell size depends on 3 parameters: • The AP power level • The protocol you use (802.11a/b/g/n/ac) • The Data rates you allow #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 16 Higher Power Does not Always Mean Better Signal Is it better now? Aim for: Blah blah blah •Noise level ≤ -92 dBm You are a bit quiet •RSSI ≥ 67 dBm RSSI -> 25 dB or better SNR dBm •Channel Utilization under 50%. Noise Level Time . What’s 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 #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 17 Next-Gen Office Design Goals Design your Roaming Path #CLUS © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 18 Where do You Need Coverage? . Talk to end-users. Think what they will need and when, look for roaming paths #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 19 Follow AP Placement Guidelines . Mount APs so that antennas are vertical (we use vertical polarization) . Avoid metallic objects that can affect the signal to your clients #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 20 Hint: This is not a sandwich Source: https://badfi.com/bad-fi/ #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 21 Just metal, concrete and walls What POSSIBLY could go wrong ? Source: https://badfi.com/bad-fi/ #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 22 “Wonder why this doesn’t work!” Source: https://badfi.com/bad-fi/ #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 23 If you love an AP, set it free.. #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 24 Rates and Cell Overlap . Cell overlap is designed so that when a VoWLAN device gets to the –67 dBm area, it is already in good range of another access point. 20-percent overlap between cells is recommended . How much is that? Use the -75 dBm rule if you are not sure. #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 26 The –75 dBm Rule . First trick to know: . Twice the distance = -6 dB . Half the distance = + 6dB At distance 2xd: (X-6) dBm At distance d: X dBm At distance d/2: (X+6) dBm (e.g. -50 dBm) (e.g. -44 dBm) (e.g. -56 dBm) #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 27 The –75 dBm Rule . So if you stand at the “-67 dBm border”… . Move away from AP 1 until you get – 67 dBm . Then pull AP 2 in the other direction until you also hear it at – 67 dBm AP 2 at – 67 dBm AP 1 at – 67 dBm AP 2 AP 1 Half way point #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 28 The –75 dBm Rule . Go back to AP 1 . AP2 should be at “– 67 – 6” = -73 dBm. Add 2-3dB loss if there is a plaster wall -> - 75 dBm 2 times the distance 1 times the distance AP 2 at – 73 to - 75 dBm AP 2 AP 1 #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 29 The –75 dBm Rule . Measure . This is your average AP to AP distance AP 2 at – 72 to - 75 dBm AP 2 AP 1 #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 30 Strategically Position Your Transition Aps . At “A” the phone is connected to AP 1 . At “B” the phone has AP 2 in the neighbor 1 2 list, AP 3 has not yet been scanned due to A B the RF shadow caused by the elevator bank . At “C” the phone needs to roam, but AP 2 is C the only AP in the neighbor list 3 . The phone then needs to rescan and connect to AP 3 – 200 B frame @ 54 Mbps is sent in 3.7 μs – 200 B frame @ 24 Mbps is sent in 8.3 μs – Rate shifting from 54 Mbps to 24 Mbps can waste 1100 μs #CLUS BRKEWN-2670 © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public 31 Strategically Position Your Transition APs . At point A the phone is connected to AP 1 1 B . At point B the phone has AP 2 in the A 2 neighbor list as it was able to scan it while moving down the hall C .