VoIP analysis module is only available to VoIP license users or
evaluation version users who selected VoIP evaluation mode.
The Real-time 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 available:
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.
The RTP 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 the
more detailed information on how to exclude RTP streams that don't
have corresponding signaling sessions.
with Lists in VoIP Analyzer