• SonicOS 7.1 Access Points
• About SonicOS
  • About SonicOS
  • SonicOS Workflow
  • How to Use the SonicOS Administration Guides
  • Guide Conventions
• About Access Points
• Settings
  • Synchronize Access Points
  • Provisioning Overview
  • Creating/Modifying Provisioning Profiles
    • Adding/Editing a Provisioning Profile - Getting Started
    • General Settings for Provisioning Profiles
    • 5GHz/2.4GHz Radio Basic Settings for Provisioning Profiles
      • Radio Settings
      • Wireless Security
      • Protected Management Frames (PMF Option)
      • About Local Radius Servers and EAP Authentication Balancing
      • Configuring Radius Server Settings
      • ACL Enforcement
      • Remote MAC Address Access Control Settings
    • 5GHz/2.4GHz Radio Advanced Settings for Provisioning Profiles
      • Configuring the RSSI Threshold
      • Configuring IEEE802.11r Settings for Secure Fast Roaming
      • Configuring IEEE802.11k Settings for Dynamic Radio Management
      • Configuring IEEE802.11v Settings for Dynamic Environment Management
    • Sensor Settings for WIDP in Provisioning Profiles
    • Mesh Network Settings for Provisioning Profiles
      • Setting Up a Mesh Network
      • Enabling a Multi-hop Mesh Network
      • Active/Active Clustering Full Mesh
    • 3G/4G/LTE WWAN Settings for Provisioning Profiles
      • Manually Configuring the 3G/4G/LTE WWAN Profile
      • Configuring Load Balancing among Multiple USB Modems
    • Bluetooth LE Settings for Provisioning Profiles
    • Deleting Access Point Profiles
    • Product Specific Configuration Notes
  • Managing Access Point Objects
    • Deleting Access Point Objects
    • Rebooting Access Point Objects
    • Modifying Access Point Objects
• Firmware Management
  • About Firmware Management
  • Obtaining the Latest SonicWall Firmware
  • Downloading Firmware from a Specific URL
  • Uploading Firmware to an Access Point
• Floor Plan View
  • Managing the Floor Plans
    • Selecting a Floor Plan
    • Creating a Floor Plan
    • Editing a Floor Plan
  • Managing Access Points
    • Available Devices
    • Added Access Points
    • Removing Access Points
    • Export Image
    • Context Menu
• Station Status
• Intrusion Detection Services
  • Scanning Access Points
  • Authorizing Access Points
• Advanced IDP
  • Enabling Wireless IDP on a Profile
  • Configuring Wireless IDP Settings
  • Viewing KRACK Sniffer Packets
• Packet Capture
• Virtual Access Points
  • Before Configuring VAPs
    • Determining Your VAP Needs
    • Determining Security Configurations
    • Sample Network Definitions
    • Prerequisites
    • VAP Configuration Worksheet
  • Access Point VAP Configuration Task List
  • Virtual Access Point Groups
  • Virtual Access Point Objects
    • General Tab
    • Advanced Tab
  • Virtual Access Point Profiles
    • Virtual Access Point Schedule Settings
    • Virtual Access Point Profile Settings
    • Remote MAC Address Access Control Settings
    • ACL Enforcement
    • IEEE802.11R Settings
    • IEEE802.11K Settings
    • IEEE802.11V Settings
    • Agile Multiband Settings
• RF Monitoring
  • Prerequisites
  • RF Monitoring Summary
  • 802.11 General Frame Setting
  • 802.11 Management Frame Setting
  • 802.11 Data Frame Setting
  • Discovered RF Threat Stations
  • Adding a Threat Station to the Watch List
  • Practical RF Monitoring Field Applications
    • Using Sensor ID to Determine RF Threat Location
    • Using RSSI to Determine RF Threat Proximity
• RF Analysis
  • Using RF Analysis on SonicWall Access Points
    • Understanding the RF Score
    • Channel Utilization Graphs and Information
    • Viewing Overloaded Channels
    • RFA Highly Interfered Channels
• RF Spectrum
• FairNet
  • Supported Platforms
  • FairNet Features
  • Management Interface Overview
  • Configuring FairNet
• Wi-Fi Multimedia
  • WMM Access Categories
  • Assigning Traffic to Access Categories
  • Configuring Wi-Fi Multimedia Parameters
    • Configuring WMM
    • Creating a WMM Profile for an Access Point
• 3G/4G/LTE WWAN
• Bluetooth LE Devices
  • Viewing BLE Scanned Data
• Radio Management
  • Configuring Radio Management
  • Configuring Dynamic Channel Selection Settings
• SonicWall Support
  • About This Document

Configuring IEEE802.11r Settings for Secure Fast Roaming

Many deployed implementations of IEEE 802.11 WiFi have effective ranges of only a few hundred meters, so, to maintain communications, devices in motion need to hand-off from one access point to another. In an automotive environment, this could easily result in a hand-off every five to ten seconds.

Hand-offs are already supported under the existing standard. The fundamental architecture for hand-offs is identical for 802.11 with and without 802.11r: the mobile device is entirely in charge of deciding when to hand-off and to which access point it wishes to hand-off. In the early days of 802.11, hand-off was a much simpler task for the mobile device. Only four messages were required for the device to establish a connection with a new access point (five if you count the optional “I'm leaving” message [deauthentication and disassociation packet] the client could send to the old access point). However, as additional features were added to the standard, including 802.11i with 802.1X authentication and 802.11e or WMM with admission control requests, the number of messages required went up dramatically. During the time these additional messages are being exchanged, the mobile device's traffic, including that from voice calls, cannot proceed, and the loss experienced by the user could amount to several seconds. Generally, the highest amount of delay or loss that the edge network should introduce into a voice call is 50 ms.

802.11r undoes the added burden that security and quality of service added to the hand-off process and restores it to the original four-message exchange. In this way, hand-off problems are not eliminated, but at least are returned to the status quo.

The primary application currently envisioned for the 802.11r standard is voice over IP (VOIP) through mobile phones designed to work with wireless Internet networks, instead of (or in addition to) standard cellular networks.