3Com V7122 User Manual page 438

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RTP Control Protocol Extended Reports (RTCP-XR) is a VoIP management control that
defines a set of metrics containing information for assessing VoIP call quality and diagnosing
problems. RTCP-XR (RFC 3611) extends the RTCP reports defined in RFC 3550 by
providing additional VoIP metrics.
RTCP-XR information publishing is implemented in the media server according to <draft-
johnston-sipping-rtcp-summary-07>. This draft defines how a SIP User Agent (UA) publishes
the detailed information to a defined collector.
RTCP-XR messages containing key call-quality-related metrics are exchanged periodically
(user-defined) between the gateway and the SIP UA. This allows an analyzer to monitor
these metrics midstream, or a gateway to retrieve them using SNMP. The gateway can send
RTCP-XR reports to an Event State Compositor (ESC) server using PUBLISH messages.
These reports can be sent at the end of each call (configured using RTCPXRReportMode)
and according to a user-defined interval (RTCPInterval or DisableRTCPRandomize) between
consecutive reports.
To enable RTCP-XR reporting, the VQMonEnable ini file parameter must be set to 1.
For a detailed description of the RTCP-XR ini file parameters, see
RTCP-XR measures VoIP call quality such as packet loss, delay, signal / noise / echo levels,
estimated R-factor, and mean opinion score (MOS). RTCP-XR measures these parameters
using the metrics listed in the table below.
RTCP-XR Published VoIP Metrics
Table 96
Start Timestamp
Stop Timestamp
Call-ID
Local Address (IP, Port & SSRC)
Remote Address (IP, Port & SSRC)
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ONTROL
R
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Metric Name
General
Session Description
P
ROTOCOL
(RTCP-XR)
Table
V7122 GatewayUser Guide
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