Optimizing wlan operations peter lane

CONFIDENTIAL © Copyright 2013. Aruba Networks, Inc. All rights reserved 1 #airheadsconf #airheadsconf

Optimizing WLANs Peter Lane

March 14, 2013

CONFIDENTIAL © Copyright 2013. Aruba Networks, Inc. All rights reserved 2 #airheadsconf

Inventory your network Monitor the health of your network Alert on critical issues Optimize RF Optimize Applications

Agenda


•  Voice/video optimization •  High Density/Large Public Venue •  Outdoor •  Advanced RF troubleshooting

Topics not covered


•  APs –  Single radio or dual radio –  a/b/g, 2 stream 11n, 3 stream 11n

•  Switches –  AP uplink speed –  Switch uplink speed

•  Applications –  Voice –  Video –  Cloud based (Salesforce, Box, Hulu, YouTube, etc.) –  Gaming –  File sharing

Routinely Inventory your network


•  Clients –  Types –  Densities –  Locations

•  Physical locations –  Odd construction materials –  Old buildings –  Sources of Interference

Routinely Inventory your network

6 6 CONFIDENTIAL © Copyright 2012. Aruba Networks, Inc. All rights reserved

ArubaOS Dashboard - Performance

Noise Floor

Channel Utilization

Interference

SNR


AOS RF Dashboard – Security


AOS RF Dashboard – WLAN


AOS RF Dashboard – Access Points


AirWave – AP Monitoring


Radio Details


AppRF AirWave Screenshots


•  Prioritize cloud based Applications –  Create a stateful firewall destination –  Add a policy using that destination to prioritize –  Pause ARM scanning for extremely latency sensitive or UDP

heavy applications (not common)

Controller ACLs and policy updates


•  Limit the bandwidth per user/role •  Limit the bandwidth used per VAP.

Bandwidth contracts and Traffic shaping


Use Reports to identify trends over time


RF Health


Rogue Client Connections

•  Don’t get blamed for other networks performance

•  Identify clients that are misconfigured

•  Identify underserved locations


Capacity planning


Use alerts to reduce work and gain visibility


Channel Utilization

•  Why is the Radio low on air time? –  Special event –  Other APs down –  Change in user behavior –  Lots of multicast

•  Frequent occurrence? –  Add APs –  Upgrade APs –  Implement bandwidth contracts –  AirGroup


•  >-85 is a concern –  Look at the SNR of

associated clients to determine impact

•  Look at nearby APs –  Is it an area wide problem or

restricted to a single AP?

Noise Floor monitoring


Radius Auth Issues

•  Find Auth issues before clients report them –  Restrict to Device or user –  Tweak levels for your

environment –  Verify RADIUS server

performance and config if problems are seen


IDS Events can cause client disruption

•  Some attacks simply disrupt the network –  Very rare –  Not an issue if only seen

once –  Repeated detections imply

someone is causing network problems

–  Don’t waste time looking for other problems when this one is purposely created


Interface Usage Monitoring

•  A saturated uplink leads to slow wireless performance


Device Event Monitoring

•  Catchall Alert –  Temp –  Fan speed –  Crash –  Etc.


•  Sticky clients –  Station handoff assist –  Lower TX power levels

•  Interference –  Non-wifi interference immunity (use with caution) –  Channel Reuse and Cell size reduction –  Lower TX power levels –  ARM channel changes –  Replace microwaves

•  Old clients –  Match AP min/max TX power to +- 3 db of client

Common Problems


Standard recommendations from VRD

Feature Setting Profile ARM Assignment Single band (default)

Multiband (for single-radio APs) ARM

Client-Aware ARM Enabled ARM Voice-Aware Scanning Enabled ARM Video-Aware Scanning Enabled ARM Load-Aware Scanning 10 Mb/s (default) ARM Power-Save-Aware Scanning

Disabled ARM

Rogue-Aware Scanning Disabled except for high security environments

ARM

Band Steering Enabled, prefer 5 GHz (default) VAP Adjusting Receive Sensitivity

Disabled Radio

Station Handoff Assist Disabled RF Optimization Intelligent Rate Adaptation

Always on, not configurable N/A

Fair Access Enabled Radio


Deployment specific settings from the VRD

Feature Sparse AP with Data Only

Dense AP with Data Only

When Enabling Video

When Enabling Voice

Spectrum Load Balancing

Disabled Enabled Enabled Disabled

Mode-Aware ARM Disabled Disabled Disabled Enable only to solve client issues

Local Probe Request Threshold

Disabled Enabled (value = 25 dB)

Enabled (value = 25 dB)

Enabled (value = 25 dB)

Dynamic Multicast Optimization

Disabled Disabled Enabled – higher of 40 or 3 x number of VLANs

Disabled


•  Know your network –  How is it used –  Where is it used

•  Monitor the health of your network –  RF health of the APs –  Client health –  Authentication issues

•  Alert on critical issues –  Leverage tools to get notified about issues

Keep Optimizing


Thank You

CONFIDENTIAL © Copyright 2013. Aruba Networks, Inc. All rights reserved 31 #airheadsconf #airheadsconf 31

32 32 CONFIDENTIAL © Copyright 2012. Aruba Networks, Inc. All rights reserved

Essential Elements of Healthy RF

Signal Strength Good Noise Floor

Channel Utilization

Client NIC

Low Interference


•  AP Characteristics –  Number and type of Radios (a/b/g/n) –  Max Tx Power –  Receive Sensitivity –  Number of Spatial Streams –  Antenna – Internal/External –  Antenna Pattern –  Number of clients supported

What Affects Signal Strength?

APs are not created equal Choose the right AP for the occasion


AP-135 Antenna Pattern


AP-93 Antenna Pattern


AP Radiated Power (EIRP)


= Radio Transmit Power (dBm)

+ Transmit Antenna Gain (dBi)

•  AP Regulatory Domain •  Country Code •  Radio Band (2.4GHz/5GHz) •  Channel (different channel has different

allowed Max EIRP)

Antenna is PASSIVE – Does Not ADD energy Higher Gain just means energy more focused

Not always a good thing


•  Attenuation (Path Loss) –  Distance from AP/Line-of-sight –  Building materials (walls, windows, partitions) –  Furniture –  People


Client Received Power (dBm) = Radiated Power/EIRP (dBm)

- Path Loss (dB)

+ Receiver Antenna Gain (dBi)


Attenuation of Common Building Material

2.4GHz 5.0GHz Fabric, blinds, ceiling tiles ~1dB ~1.5dB Interior drywall 3-4 dB 3-5 dB Cubicle wall 2-5 dB 4-9 dB Wood door (Hollow – Solid) 3-4 dB 6-7 dB Brick/Concrete wall 6-18 dB 10-30 dB Glass/Window (not tinted) 2-3 dB 6-8 dB Double-pane coated glass 13 dB 20 dB Steel/Fire exit door 13-19 dB 25-32 dB


•  Disable Bcast if possible •  AirGroup when possible –  Management frames –  Lowest data rates –  Large subnets bring in large bcast domains

•  SSID profile –  Bcast/mcast on the SSID •  Set to ARP

Broadcast Optimization


•  Watch out for DHCP lease issues •  Short leases recommended depending on usage –  30-60 min for guest networks –  6 to 8 hours for .1x

DHCP

Business

Optimizing wlan operations peter lane