Transport Reliability IP Probe

This reliability tool tests your Internet connection to a Microsoft Lync Online Service data center and measures the response times, bandwidth, allowed ports, route taken, and overall connection quality with respect to Real Time Media. The results can help you evaluate your network configuration for potential use with the Microsoft Lync Online Service. This tool does not engage any of the offerings from Microsoft Lync Online Service. Instead, it focuses on the quality of your connection to the Microsoft Lync Online Service data center.


This tool helps you understand the quality of the Internet connection between your environment and Microsoft Online Services. It does not measure your environment compatibility with Microsoft Online Services. The tool performs three tests:

  • Speed: This probe measures your actual download and upload speeds, quality of data, and TCP efficiency. It uses TCP/50000 for download testing and TCP/50001 for upload testing.
  • Route: This probe validates your connection quality, including packet loss, latency, round trip, and ISP peering points. It uses Internet Control Message Protocol (ICMP).
  • VoIP: This probe measures your expected VoIP quality by measuring VoIP specific metrics using your Internet Connection.
  • Firewall: This probe validates your network firewall is not blocking ports necessary for the Microsoft Lync Online Service. It tests for outbound connection to TCP/443 for Client Signaling, TCP/5061 for Federation Signaling, UDP 3478 for Media Access, and UDP/50,000-59,999 for Media Range.

Disclaimer:  Depending on your network and security environment, not all tests may be successful. A test success or failure does not mean that your environment is compatible or incompatible with Microsoft Lync Online Service. This performance tool is provided for use “as-is.” The customer bears the risk of using it. Microsoft gives no express warranties, guarantees, or conditions.

By activating the tool, you consent to Microsoft"s collection and use of your IP address, country location and browser type in accordance with the privacy statement.