Article ID: 2386655 - View products that this article applies to.

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When you try to connect to a Microsoft Lync Online conference or make a peer to peer call, the audio or video quality may be choppy, tinny, or delayed. This causes the meeting or call to be unusable.


There are tools that you can use to determine the source of the issue.

In Microsoft Lync 2010 and Microsoft Lync 2013, you can use voice and video quality indicators to identify how well you're being heard or viewed. New indicators that are displayed in the conversation window tell you when conditions are present that may affect the quality of the voice or video call. These conditions may include poor network connectivity, low-bandwidth network connections, or poor audio quality from a particular device. In scenarios in which you experience poor audio quality, click the indicator to display possible reasons for the audio issue and to link to relevant resources.

Lync 2010

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Screen shot of the vioce and video quality indicator in Lync 2010

Lync 2013

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Screen shot of the vioce and video quality indicator in Lync 2013

As a general guideline, to troubleshoot scenarios in which you experience poor audio or video quality in a Lync Online conference, follow these steps:
  1. In a web browser, browse to the Office 365 Lync Online Transport Reliability IP Probe (TRIPP) tool URL that's closest to the user's physical location, and then click Start Test:
    After the tool finishes, examine the following graphs and statistics that are generated by the tool. This data may indicate connectivity or bandwidth problems with the Lync Online service.
    • The Media Access test
      The Media Access test verifies that the client computer can connect to the Lync Online media servers over port 3478 (UDP). If the test fails, check firewall routing rules to make sure that port 3478 over UDP is open for both incoming and outgoing connections.

      If this port is blocked, symptoms that you experience include audio/video calls that don't connect, desktop sharing and other collaboration features that don't connect, and conference join failures.

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      Screen shot of Media access test result
    • The AudioVideo - lowerbound and AudioVideo - upperbound tests

      If the AudioVideo - lowerbound and AudioVideo - upperbound tests fail, check whether ports 50,000 through 59,999 (UDP) are open on the network firewall. The tool can't check all the ports in the range. It assumes that if both the lowerbound port and upperbound port are open, the ports that are in between the lowerbound and upperbound port are also likely open.

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      Screen shot of the test result for the AudioVideo - lowerbound and AudioVideo - upperbound
    • Download and upload speeds

      Download and upload speeds can affect the quality of the audio/video connection or the collaboration features. If the download or upload speed is less than 1 Mbps, the audio/video quality may be degraded. For more information about bandwidth requirements, go to the following Microsoft TechNet website:
      Media Traffic Network Usage

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      Screen shot of the test result for download and upload speed
    • The VoIP test

      The Voice over IP (VoIP) text checks to make sure that the connection has a consistent round-trip response time and validates the Consistency of Service. If the response rates for each packet vary too much, or there's too much packet loss, the audio/video connection may be jittery or choppy. Connections that have over 5 ms jitter or over 2 percent packet loss may experience degraded quality in audio, video, or application sharing. Switching to a more consistent connection or reducing the number of hops in the route may resolve this issue.

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      Screen shot of the VOIP test result
    • The Summary Page

      The Summary page shows the results from all the tests. If any of the status indicators are yellow or red, connections to Lync Online may be degraded or may fail.

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      Screen shot of the summary page

      For example, the following test result shows a yellow status indicator for Consistency of Service, and this could cause broken sound or video quality.

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      Screen shot of test result, showing a yellow status indicator
  2. Determine whether the computer is using a wired or wireless Internet connection. A wired connection can provide more bandwidth and stability in most cases and should be the preferred method of connecting if that kind of connection is available. Additionally, consider turning off any wireless antennas to avoid connecting through a wireless connection.
  3. Make sure that the audio/video device that is being used is approved and certified to work with Lync 2010. For more information, see the following Microsoft TechNet topic: USB Peripherals
  4. Select the correct device, and make sure that the recording volume is at the appropriate level. In the upper-right area of the window, click the gear icon, click Tools, click Options, and then click Audio Device. Verify that the appropriate device is selected.

    Adjust the Microphone slider to the volume level that you want. Speak at your usual voice level. The indicator should go no higher than the midway point.


This issue may occur for many reasons, such as network latency, video or audio driver configuration issues, or device configuration issues.

Still need help? Go to the Office 365 Community website.


Article ID: 2386655 - Last Review: September 6, 2013 - Revision: 40.0
Applies to
  • Microsoft Office 365 for enterprises (pre-upgrade)
  • Microsoft Office 365 for small businesses  (pre-upgrade)
  • Microsoft Office 365 for education  (pre-upgrade)
  • Microsoft Lync Online
o365 o365a o365e kbgraphxlink o365p o365m o365022013 after upgrade o365062011 pre-upgrade kbgraphic KB2386655

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