VoIP analysis module is only available to VoIP license users or
evaluation version users who selected VoIP evaluation mode.
Transport Protocol (or RTP) defines a standardized packet format
for delivering audio and video over the Internet. While protocols
like SIP or H.323 are used to control the call (e.g. setting up a
connection, dialing, disconnecting, etc.), RTP is used for reliable
transmission of data packets and maintaining Quality of Service. In
other words, RTP streams carry the actual voice payload encoded
utilizing one of a number of codecs, and analysis of RTP data
provided invaluable information for assessing call quality and
troubleshooting VoIP networks.
To view RTP
streams captured by the application, select RTP
Streams in the left pane of the
VoIP analyzer window:
The upper part
displays a complete list of all RTP streams. When selecting a RTP
stream from the list, the lower pane displays detailed information
on the selected stream, including the complete list of RTP packets,
summarized and statistical data, as well as the charts:
Up to four
different charts for the selected stream can be displayed
simultaneously, with the window interval from 5 to 60 seconds. Note
that right clicking and dragging the graph will scroll it to the
left or right respectively. The following chart types are
number of RTP packets per second including duplicates, lost
packets, and "out of order" packets.
Bandwidth – stream speed in terms of
kilobits per second.
average sizes of RTP packets broken down by network and RTP
headers, and RTP payload.
MOS Score – stream quality
Intervals – temporal allocation of
RTP packets in a stream.
Streams list contains all captured RTP streams, both belonging to
SIP or H.232 signaling sessions, and the ones for which signaling
sessions were not identified (so called 'orphan' streams, i.e. the
ones that don't belong to any parent session). Please refer to
more detailed information on how to exclude RTP streams that don't
have corresponding signaling sessions.
with Lists in VoIP Analyzer