ConferenceXP Diagnostic Service

From UW Center for Collaborative Technologies Wiki
Jump to: navigation, search

The ConferenceXP Diagnostic Service provides administrators and users with a tool for understanding end-to-end networking problems. It provides information about venue participants, data transmission rates, and packet loss rates. This information is made available through a dynamically-updated web site. A subset of this information is also presented in the ConferenceXP Client.

Installation and Setup

Please refer to ConferenceXP 5 Installation Notes for complete information about Diagnostic Service setup.

The Diagnostic Service runs as a web service inside of Microsoft IIS. As such, its installation is nearly identical to the ConferenceXP Venue Service. Simply replace the Venue Service installer with the Diagnostic Service installer in Step 3.

Each client must be configured to use the Diagnostic Service. From the Client GUI, this option resides under Settings => Services. Specify the complete URL to the diagnostic service. For example: http://myhost.mydomain.com/diagnosticservice

You may also specify a Diagnostic Service in the client configuration file (CXPClient.exe.config). Below is a sample configuration key for a Diagnostic Service:

   <add key="MSR.LST.ConferenceXP.DiagnosticService"
   value="http://somehost.somewhere.com/diagnosticservice"/>

Diagnostic Information

The diagnostic web page provides network-level information about the senders and receivers in a ConferenceXP Venue. First, select your venue from the drop-down list in the upper-left corner. For each venue, you should see three tables of information: sender information, throughput differential, and loss rate.

The Diagnostic Service can present data in a basic mode or an advanced mode. The differences are described below.

Sender Information

The Sender Information Table provides information about each "sender" in a venue. In basic mode, each host is a single sender. In advanced mode, each RTP stream is a single sender. For example, advanced mode distinguishes between the audio and video streams from a single host.

For each sender, we display the total data sent, and the data rate from the last reporting interval. Typically, clients report their sending rate over a window that lasts several seconds. We also report the time of the last update for each sender.

The web page does not refresh automatically. The "Refresh" button is provided for this purpose.

Throughput Differential

This table shows the difference between sent data and received data at each <sender, receiver> pair. Each row represents a "receiver", which is always an individual ConferenceXP clients. The columns with numbers represent senders, which can be other ConferenceXP clients (basic mode) or RTP streams (advanced mode).

Under perfect conditions, the throughput differential would be zero. In practice, the throughput differential tends to fluctuate around zero, even for networks without loss. This is because there is no synchronization between the updates from senders and receivers.

Loss Rate

The third table shows the loss rate between each <sender, receiver> pair; senders and receivers are defined in the same manner as the previous table. Note that this table can give spurious results during complete network outages (100% loss). This is because clients cannot distinguish between a network outage and a silent sender. Thus, it is always a good idea to corroborate the loss rate data with the throughput differential (which should be robust in the face of network outages).