Roaming SLE

What Does the Roaming SLE Measure?

Juniper Mist tracks the percentage of successful roams between access points and assigns a quality score from 1 to 5. A score of 1 indicates excellent roaming, and a score of 5 indicates poor roaming.

You can click the Settings button to set the roaming score to use as the success threshold for this SLE.

Classifiers for Poor Roaming

When the roaming threshold is not met, Juniper Mist classifies the issues as follows.

• Latency—Roaming time was excessive.

  Latency has different sub-classifiers for different roaming options:

  • Slow 11r Roams—This classifier applies to fast roaming as defined by 802.11r. The roaming time exceeded 400 minutes.

  • Slow Standard Roams—This classifier applies to standard roaming. The roaming time exceeded 2 seconds.

  • Slow OKC Roams—This classifier applies to clients using RADIUS-based authentication with Opportunistic Key Caching (OKC). The roaming time exceeded 2 seconds.

• Stability—This classifier tracks the consistency of AP choice and 11r usage during client roams. Juniper Mist assigns this classifier if a user capable of fast roaming on a fast- roaming enabled SSID experiences slow roaming for more than 2 seconds. This classifier contains one sub-classifier: Failed to fast Roam.

• Signal Quality—This classifier tracks the RSSI of clients during a roaming event.

  • Suboptimal Roam—This sub-classifier tracks when clients roam to an AP:

    • With more than 6 dBm decrease in RSSI compared to the client's RSSI in the previous AP

    • If the RSSI in the new connection is worse than the configured coverage SLE threshold. Note that the default coverage SLE threshold is 72 dBm.

  • Sticky Client—This sub-classifier tracks the events when a client remains connected to an AP even when more roaming options are available to improve the RSSI by more than 6 dBm.

Example

• Success Rate—On the left, you see that 99 percent of roaming attempts met the threshold.

• Timeline—In the middle, you can drag your mouse to explore the success rate over time. In this example, there was a 100 percent success rate at the selected time. To adjust the scope of the timeline, use the timeline drop-down list at the top of the Monitor page. For example, set the timeline to Today, Yesterday, This Week, or a custom date range.

• Classifiers—On the right, you see a high-level root cause analysis for the roaming attempts that did not meet the threshold. The vast majority of the issues (92 percent) were attributed to Signal Quality. The other 8 percent were attributed to Stability. No issues (0 percent) were attributed to the other classifier.

Note:

You can click the Values button to show numbers instead of the success rate and the classifier percentages. In this example, the left side of the screen shows the average roaming score during the specified time period. The timeline shows the average roaming score at each point in time. The right side of the screen shows the number of roaming attempts that were impacted by each classifier.