RTP Reception Quality Matrix
14 October 1999
/ rat
The Real-time Transport Protocol, RTP, provides quality of service
feedback through reception reports sent alongside an audio/video stream.
If the media stream is sent via IP multicast, it is possible for a third
party to monitor these reception reports and display reception quality
for all members of a multicast group. The RQM application performs such
monitoring.
When running RQM displays a matrix with participant details on the
left, and a number of cells to the right of these. Each row of cells
denotes the packet loss rate observed for data sent from the participant
indicated at the left of that row (point to a cell and a popup will
appear giving the names of the source and destination of the
traffic represented by that cell).
The colours of the cell start as green (no loss) and fade to red (20%
loss). A white cell indicates that no information is available. A
light blue cell indicates that the receiver is not receiving media data
from a particular sender (at present light blue is only used when an
empty reception report is received, indicating that a receiver can hear
no-one).
Clicking on a cell will initiate an mtrace between the indicated
participants, if you have mtrace installed and available in your path.
The source code is
available for download. It was last modified in 1999, and whilst it
compiled and ran on the versions of Solaris and Linux available then,
it may not do so on current versions.