Calls that last for more than 30 seconds and show very high packet loss are false positives. In these cases, there is no actual packet loss. Calls with true high packet loss would not last more than a few seconds. Polycom phones may erroneously report packet loss due to synchronization source (SSRC) changes. This is a known issue with Polycom phones, and is being addressed in a new firmware version.
For a call with a rating of good or excellent that actually had poor quality, there are two possible scenarios:
To find out what kind of loss was experienced (evenly distributed or in bursts), click next to the Call Quality Detail report to open advanced details in the Endpoint Voice Quality Report. Look for the Burst Loss Density (BLD). The range is from 1 to 100 for desk phones such as Polycom. The range is from 1 to 255 for the Virtual Office desktop app app and Virtual Office mobile app. The closer the number is to 100 (or 255, in the case of Virtual Office), the more likely it is that the loss happened in a burst (sudden loss of data, creating a gap or poor quality for a short period). The smaller the number, the more evenly distributed the loss was (or the loss did not happen as frequently during the bursts). For example, you see a call quality report that lists a Local.BurstGapLoss of BLD:99.6 which indicates the loss happened in a burst. The following image displays where to find the BLD information in the report.
To see the call quality details:
Open topic with navigation