Transcript SIP-Based Voice Measurement Infrastructure

SIP-Based Voice Measurement
Infrastructure
Cesar Marcondes
UCLA
Motivation
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Voice Measurements
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Predict Voice Quality
Gateway Provisioning
Assessment of Priority Voice over IP Calls
in SIP.edu
Debugging Misconfigured sites
Background/Issues
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We worked during the year 2003 in a similar idea in
Brazilian Academic Network (RNP2)
Quality of voice can be determined through
quantitative metrics mapping to Mean Opinion Score
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MOS: Poor, Regular, Good, Excellent
And objectively calculated through
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E-Model (ITU-T G.107 and ETSI ETR 250)
We can approach in two ways:
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Active Quality Monitoring
Passive Quality Monitoring
Voice Measurement Models
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Active monitoring - using
remote answering machines
(client/server model),
generate call, not real ones,
but "emulated". Assess
network impairments.
Generate N
VoIP flows
(change codec/
dejitter/fec)
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Passive monitoring of real
calls - capture statistics from
real calls, use sniffer near
the "gateway" to detect VoIP
flows and obtain the call leg
RTP/RTCP
Answering
Machine (Remote)
Passive Monitor
Machine
VoIP flows
Call Generator w/
Pre-Recorded
VoIP Message
Mirror Port
Access Switch
/Router
Answering
Machine (Remote)
VoIP Gateway
PBX
Research Ideas
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VoIP Scalable Measurement Infrastructure
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Propose an automatic and robust architecture,
implementation, support from SIP.edu (remote sites for
active measurement), best practice cookbook (?)
Other research interests:
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Assessment of VoIP calls over Wireless Hotspots in SIPenabled campus
Design, Implementation and Assessment of TCP-rate based
protocol (focus on VoIP as the payload) – the idea is obtain
some “level of QoS” through dynamic changes in the cwind
grow/decrease rate
Related Projects
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H.323 Beacon (there could be necessary to
implement a SIP version of this tool)
 http://www.itecohio.org/beacon/
Brazilian Academic Network (RNP) tools (basically
they have an E-Model Implementation)
 http://www.voip.nce.ufrj.br/
Cisco/other vendors VoIP quality measurements tools
in-built
Cisco Works2000 VoiceManager