Cisco connect winnipeg 2018 optimizing your client's wi-fi experience v4 - public

© 2017 Cisco and/or its affiliates. All rights reserved. 1
Optimizing Your Wi-Fi
Thoughts & Tools For
The Modern Network Operator
May 29 2018
Cisco
Connect

If you have delivered wireless
voice, with seamless L3 roaming,
in a
“all wireless environment” with
no control over your clients….

AND HAVE NEVER HAD
A PROBLEM…

You may be interested in a more
more appropriate session….

Part 1: Optimizing Layer 1
Part 2: Optimizing Layer 2
Part 3: Innovations for Improved Client Experience
Part 4: What is possible in non Apple Environments?
Part 5: What changes will 802.11ax bring?
Agenda

Acknowledgement
• A large portion of this presentation was gleaned from the Cisco Live Berlin 2017 Session:
Wireless Deployment and Design for Media-Rich Mobile Applications
https://www.ciscolive.com/online/connect/sessionDetail.ww?SESSION_ID=93867&backBtn=true. I
highly recommend viewing it in it’s entirety and I thank my colleagues for allowing me to use their
content. Said session was created and delivered by the following Principal Engineers:
• Robert Barton, P. Eng
@MrRobbarto CCIE #6660, CCDE #2013::6
• Jerome Henry, Technical leader - TME
@wirelessccie CCIE Wireless #24750, CWNE #45
More related presentations and references will be noted in the supplemental information slide(s)
following the core material of this delivery.

Optimizing Layer 1

Where do You Need Coverage?
 Talk to end-users. Think what they will need and when, look for roaming paths
Part 1

AP Placement Guidelines
 Mount APs so that antennas are vertical (we use vertical polarization)
9Part 1

Radiation Pattern
 Do not mount on a wall an AP built for ceiling
mount…
Part 1

AP Placement Guidelines
 Avoid metallic objects that can affect the signal to your clients
Part 1

AP Placement – Bad Examples
 AP too high:
Low rate to the ground
Client signal too weak at the AP level
> 20ft
Nice… but you won’t cover the
jetway as soon as the door closes
Part 1

AP Placement – Too Many, (4AP’s in <500sqft?)
Part 1

RF Design – Cell Overlap
• Cell overlap coverage is not always the only concern
• Roaming can fail if the client device does not have enough time to
properly scan for neighboring access points
Imagine turning the corner around a metal or high attenuation barrier –
the RF environment changes very rapidly – no time for client to react
• Challenging RF obstacles need to be considered during AP placement
• A “Transition” AP that is placed at the intersection of hallways can
alleviate some scenarios
Part 1

RF Design – Next AP Position
• At point A the phone is connected to AP 1
• At point 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
• At point 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 3
1
3
2A B
C
Part 1

RF Design – Next AP Position
• 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
• 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
A B
C
1
2
3
Part 1

Radiation Pattern and Its Impact on Roaming
 When users are expected to roam while communicating, make sure their device can detect
neighboring APs BEFORE roaming…
AP signal drops fast
AP signal drops slowly
User does not have much space/time
to find the next AP
Part 1

Consider The Network Path Along The Way….
Design expected roaming paths and make sure all APs connect to the same controller, and overlap
allows for next AP discovery
Part 1

Going Further
• BRKEWN-2019 - 7 Ways to Fail as a Wireless Expert (2017 Berlin)
• https://www.ciscolive.com/online/connect/sessionDetail.ww?SESSION_ID=93858&backBtn=true
• BRKEWN-3010 - Improve enterprise WLAN spectrum quality with Cisco's advanced RF capacities (RRM,
CleanAir, ClientLink, etc) (2017 Berlin)
• https://www.ciscolive.com/online/connect/sessionDetail.ww?SESSION_ID=94062&tclass=popup
Part 1

Optimizing Layer 2

Voice over Wi-Fi is To A Network Admin Like…

VoIP Golden Rules for Wi-Fi
Packet Error Rate (PER) <=1%
As low jitter as possible, less than 100ms
Retries should be < 20%
End to end delay 150 – 200 ms, 30 ms in cell
When these values are exceeded, MOS reduces too much
Your mission is to keep MOS high
Success with voice = success with almost anything else
Part 2

But First,
The Fundamentals
Part 2

RF Design – Signal Power & Inverse Square Law
• Closer distance to the AP means higher signal level (RSSI), which translates to a more complex
modulation scheme and therefore higher data rate.
Surprisingly long distances can be achieved at low data rates
Part 2

RF Design – Two Handy & Related References
mcsindex.com AP datasheet (RX Sensitivity Section)
Part 2

Part 2

Higher Power Does not Always Mean Better Signal
You are a bit quiet
Blah blah blah
Is it better now?
RSSI
dBm
Noise Level
Time
Aim for:
•Noise level ≤ -92 dBm
•RSSI ≥ 67 dBm
-> 25 dB or better SNR
•Typically, AP power same as client power
-> commonly 11 to 14 dBm
Part 2

Imagine This Scenario . . . .
(based on an actual customer situation)
1
1
1
1
1
1
1
1
1
• 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)
~ 120 ft
Part 2

SSIDs and Low Rates Consume Air Time
 Reduce SSID number,
disable low
rates, solve L1 issues
 Keep CU below 50%
 Before: 8 SSIDs, all
rates allowed
 After: 2 SSIDs, 802.11b
rates disabled
Assess Channel Utilization Often!
Part 2

What Should Your Minimum Rate Be?
 Stop your cell where:
1. Signal to your clients is still strong
2. Clients and overhead traffic still “reasonably fast”
3. Retries are low
 Beyond that point, clients should be able to get to another AP
if they want to.
 On the right:
 STA1 and STA2 hear each other -> less collisions
 STA 1 and STA2 send @ 54 Mb/s -> short delays
 STA3 is far from AP -> lower data rate (longer transmission delay),
higher PER and loss risks
 STA3 does not hear STA1 and STA2 -> higher collision risk
24 Mbps
6 Mbps
STA1
STA2
STA3
Part 2

Hand and Phone Position Affect Signal
Object in Signal Path
Signal Attenuation
Through Object
Plasterboard wall 3 dB
Glass wall with metal frame 6 dB
Cinderblock wall 4 dB
Office window 3 dB
Metal door 6 dB
Metal door in brick wall 12 dB
Phone and body position 3 - 6 dB
Phone near field absorption Up to 15 dB
There can be a 20 dB difference
between these photos
Part 2

Big Hands are Okay if Your Design is Clever
-67 dBm
-67 – 20 = -87 dBm
Signal is too weak…
AP
AP
But you can roam to the other AP @ -67 dBm!
Part 2

 Does it look broken
 Neighbor relations
 Channel assignments even
 Physical layer issues
 Roaming issues
 Client Disconnects
 Intermittent issues/no apparent pattern
 Throughput/capacity issues
 Load balancing issues
Quick and Easy Validation
How do you if KNOW if RRM is working fine?
If it had a proper foundation
It wouldn't be a tourist attraction
34
Part 2

 Everything – depends on Neighbor Relations
 DCA channels –
 TPC Power levels –
 Coverage Hole Detection-
 Optimized Roaming –
 802.11v, 802.11k –
 CleanAir –
 FRA
 If Neighboring or NDP is broken – ALL of RRM’s output is Broken
 What to check – Top to Bottom
Neighbors, Channel and Power – In that order
Does it Look Broken?
35
Part 2

 Display Channels on the
Floor Map –
 Visually identify Adjacent
AP’s on same or adjacent
channels
 Do the same with TX
Power, associated clients,
Channel utilization
 Useful information – In
Context
Get Context!
Prime Maps – A Great Place to Start
36
Part 2

 Select RX Neighbors
and point-
 Neighbor relations are
displayed
 Validate that Same
Channel AP’s are not
to RF Close
 What’s Too Close?
 That depends – but
greater than -72 is
usually
Prime Maps – A Great Place to Start
Selected
Chn 64
Selected
Chn 64 -79 dBm
Selected
Chn 64 -63 dBm
Selected
Chn 64 -77 dBm
*From Prime 3.2 – Next Generation Maps
37
Part 2

 Per Band (2.4 and 5 GHz)
 TX Power Distribution of all AP’s
 Channel Distribution of all AP’s
 RSSI Spread of all Clients
 SNR Distribution of All Clients
When you need the needle to Jump from the Haystack!
WLCCA – WLC Config Analyzer
38
Part 2

 Is it Even-ish?
 If It’s obviously lopsided –
then DCA may be stale
 Why and What to do – a little
later
 Look at Channels 120,124,
and 128
 How many –B AP’s do they
have?
Channel Assignments –
Channel Distribution 2.4 Band:
Number of Radios on channel 1: 1399 (53.07%)
Channel Distribution 5.0 Band:
Number of Radios on channel 104: 11 (.37%)
39
Part 2

• Assuming TPC
• Are the AP’s in the mid power levels?
• Or are they disproportionate
• You can tell a lot about a network by how
TPC applies power Dense/Thin
• Remember TPC min/max and RF
Profiles….
40
Power Level Distribution 5 Band:
Number of 5.0 Band Enabled Radios with Power Level 1: 1060 (35.84%)
Number of 5.0 Band Enabled Radios with Power Level 8: 8 (.27%)
Power Level Distribution 2.4 Band:
Part 2

 This is How the Network
Hears the Client
 This tells us where the network
is in relation to the clients
Client RSSI Distribution
WLCCA – WLC Config Analyzer –
Client RSSI Distribution 2.4
Band:
Number of Clients with RSSI -100: 9 (.14%)
Number of Clients with RSSI -92: 462 (7.08%)
41
Part 2

Client SNR Distribution 5.0 Band:
Number of Clients with SNR 0: 106 (.90%)
Number of Clients with SNR 5: 349 (2.95%)
Client SNR Distribution 2.4 Band:
 Client SNR is the Client RSSI –
at the AP, and the Noise – At
the AP!
 SNR Determines the Data Rate
that can/will be used
 25 dB is a common design goal
Client SNR Distribution
44% < 25 dB!
32% < 25 dB!
This tells you a LOT about how efficient a network can possibly be
42
Part 2

Innovations for Improved Mobile
Quality Of Experience
Part 3

So Why Does Roaming Suck?
Part 3
All of this every time the device roams…
source: MY802.11.com

© 2017 Cisco and/or its affiliates. All rights reserved. Cisco Confidential
What happens Today?
In 802.11, delay in roaming causes
poor experience, especially for
rich-media real-time applications.
Interoperability increases complexity
and prevents adoption.
Standards to the rescue?
• 802.11r – Fast Roaming
• 802.11k – Neighbor List
• 802.11v – BSS Transition
But
• Operational Complexity
• Multiple SSIDs – some clients can’t
associate with SSIDs enabled with 11r
Part 3

802.11k, 802.11v, 802.11r help efficient roaming
Fast Transition (802.11r)
802.11r enables fast roaming without complete reauth
802.11k sends you list of neighbors
802.11v BSS Transition sends you the new best AP: Cisco-AP-2Association
Cisco-AP-1 Cisco-AP-2
Part 3

802.11v & Radios On the Same AP
-51 dBm
47
Macro Cell
Micro Cell
Part 3

Association
802.11k, 802.11v, 802.11r help efficient roaming
Cisco-APNon-Cisco-AP
Legacy client cannot
join the same SSID
where 11r is enabled
I recognize that you
are an iOS device
11r is enabled for you
802.11k, 802.11v
are on by default
Legacy client that does
not support 11r/k/v can
join the same SSID
Part 3

What Happens
Today?
IT cannot prioritize business-critical
real-time traffic all the way from
clients to the destination
Today IT Administrators can classify traffic
ONLY at the access point. This implies:
• Inability to prioritize between the client and
the AP
• Burden on IT administrator to manage the
applications across the enterprise
Part 3

Prioritizing Business Apps
Prioritize business critical apps and real time data
Turning on is easy
IT has control over which apps get priority
Part 3

Fast lane Configuration Profiles
A QoS configuration profile will ONLY be acted upon on a iOS 10, iOS 11, macOS
High Sierra or later device
Uses standard configuration profiling techniques (MDM, email, Web-based)
The 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
Part 3

Fast lane only applies to Cisco and Apple
Deployments
Cisco-APNon-Cisco-AP
QoS Profile is
not considered
Applications can
only mark UP,
not DSCP*
QoS Profile or
no QoS Profile
Supports Fast lane
If a Profile was
received, All apps in
WhiteList Can mark
QoS upstream
QoS
Profile
* DSCP can be marked in some restricted conditions
Part 3

Fast lane enables network administrator to prioritize
applications per your environment
Cisco-AP
Supports
Fast lane
Admin can provision Apple iOS device and Mac computer
with a QoS profile*
Applications in whitelist get QoS marking
Other applications get BE/BK
Supports
Fast lane
Supports Fast laneSupports Fast lane
My profile for
this environment:
Minecraft = Real time
interactive
Viber = BE
My profile for
this environment:
Minecraft = BE
Viber = Voice
Cisco-AP
*Without a profile, all applications are whitelisted by default in a FastLane cell
**FastLane does NOT override apps QoS, it either allow the app QoS or apply BE Part 3

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
Part 3

Optimizing Wi-Fi
Connectivity
QoS Profile
Voice QoS Trust
AutoQoS
Better EDCA
Helps determine which applications
should receive QoS upstream
Trust upstream voice traffic, with
ACM and without TSPEC
Benefits IT Administrator
Configure optimal WLC QoS in one
click
Ease of Use
IEEE 802.11-2016 EDCA
Part 3

Benefits of App Prioritization
1
2
3
Business data gets priority and speed even if network is
congested
Reduces complexity - IT can focus on the business – the
network does the heavy lifting
Better reliability for business apps that demand a high quality of
service
Part 3

What About My Other Clients?
Part 4

Optimized Roaming
RX-SOP
Pervasive Wi-Fi
HDX Turbo
Performance
Event Driven
RRM
XOR Radio
FRA
Cisco CleanAir®
RF Profiles
RRM, DCA, TPC, CHDM
Load Balancing
Band Select
Client Link 4.0
Off-Channel
Scanning
Flex DFS
DBS
5GHz
Serving
2.4GHz
Serving
5/2.4GHz
Monitor
• Enabled by Dual 5GHz
• Adjust Radio Bands to Better Serve the
Environment
RF Optimized
Connectivity
Part 4

XOR Radio and FRA
2.4GHz
Serving
2.4-5GHz
Monitoring
5GHz.
Serving
5GHz.
Serving
2.4GHz
Serving
5GHz.
Serving
5GHz
Serving5Hz
Serving
2.4GHz
Serving
 FRA-auto (default value) or Manual
 Auto 2.4 -> 5GHz or Monitor Mode
 Transition to 2.4 GHz if coverage drops
Part 4

Micro  Macro Cell Transitions
-51 dBm
-65 dBm
-51 dBm-51 dBm≥ 55
dBm?
Probe Response
Client Steering
• 802.11v BSS Transition – Default Enable
• 802.11k – Default Enable
• Probe Suppression – Default Disable
Client Types
• 11v capable – 802.11v BSS Transition
• Non-11v capable – 802.11k neighbor list +
disassociation
• No 11k or 11v support – Probe Suppression Micro – 5GHz on XOR
Macro -- Dedicated 5 GHz
Part 4

Better Support for Users on the Move
Optimized Roaming
Optimized Roaming: Wireless Devices
Connect to the Most Effective APClient Stickiness
Part 4

Better Client Connectivity
RXSOP, Load Balancing, Band Select
Part 4

Fine-tuning HDX with RF Profiles
Wi-Fi Triggered
ED-RRM
Optimized
Roaming
RXSOP
Dynamic
Bandwidth
Selection
TPC, DCA
CHDM
FlexDFS
CORE:
• CleanAir
• ClientLink 4.0
• Turbo Performance
 Pre-canned RF Profiles
 Client Distribution
 Data Rates
 DCA, TPC, CHDM
 Profile Threshold for Traps
 High Density Features
Part 4

Cisco Air Time Fairness (ATF)
After
Air time is allocated per SSID, per realm, per client.
There is now better control over how air time is shared.
Before
Rate limiting can only specify a bit rate (throughput) limit.
There is no way to limit the duration that the bit rate will use.
Time-
based
Automatic
calculation
on
availability
Ongoing
recalculation
Bandwidth
rate
unpredictable
Client-
dependent
fluctuation
Not time-
based
Improved Predictability and Performance
SSID 2
30%
SSID 1
70%
SSID 2
48%
SSID 1
52%
Part 4

& Last - Zero Impact Application Visibility and Control
Maintain performance with zero-impact AVC
Gain visibility
into the network
Control application
performance
App App App App
App App App App
App App App App
App App App App
Red Hat
Cisco
WebEx
Rhapsody Gmail
TIBCO
Microsoft
Exchange
YouTube Skype
SAP Citrix BitTorrent iTunes
SharePoint
Windows
Server
Google
Talk
Salesforce
Monitor critical
applications
Part 4

What changes will 802.11ax
make to all of this?
Part 5

2.4 GHz only
1 transceiver
<10Mbps
2.4/5G + 5GHz
12 transceivers
mGig (.3bz) PHY
>2.5Gbps
Part 5

Part 5

802.11ax Coverage At Highest Speeds
Source: National Instruments (ni.com) Part 5

802.11ax Coverage At Lowest Speeds
Part 5

802.11ax – One @ A Time vs. Many @ At Once…
Part 5

802.11ax – The Task Group Members
Source: IEEE.org
Part 5

802.11ac vs 802.11ax
Source: National Instruments (ni.com) Part 5
Dual band
6dB better noise performance
More robust modulation

802.11ax – Chipsets – Who’s First?
• Silicon[edit]
• On October 17, 2016, Quantenna announced the first 802.11ax silicon, the QSR10G-AX. The
chipset is compliant with Draft 1.0 and supports eight 5 GHz streams and four 2.4 GHz streams. In
January 2017 Quantenna added the QSR5G-AX to their portfolio with support for four streams in
both bands.[49] Both products are aimed at routers and access points.
• On February 13, 2017, Qualcomm announced their first 802.11ax silicon.[50][51][third-party source
needed] The IPQ8074 is a complete SoC with four Cortex-A53 cores. There is support for eight
5 GHz streams and four 2.4 GHz streams. The QCA6290 chipset which supports two streams in
both bands and aims at mobile devices.
• On August 15, 2017, Broadcom announced their 6th Generation of Wi-Fi products with 802.11ax
support.[52][third-party source needed] The BCM43684 and BCM43694 are 4×4 MIMO chips with full
802.11ax support, while the BCM4375 provides 2 × 2 MIMO 802.11ax along with Bluetooth 5.0.
• On December 11th, 2017, Marvell announced 802.11ax chipsets consisting of 88W9068,
88W9064 and 88W9064S.[citation needed]
Source: https://en.wikipedia.org/wiki/IEEE_802.11ax

802.11ax – Resource Unit Allocations
Source: National Instruments (ni.com)

802.11ax – Tone Map
Source: National Instruments (ni.com)

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