international telecommunication union workshop on end-to-end quality of service.what is it? how do...

International Telecommunication Union

Workshop on End-to-End Quality of Service.What is it? How do we get it?Geneva, 1-3 October 2003

Common VoIP Common VoIP MetricsMetricsAlan Clark

CEO, Telchemy

21-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Summary

o Typical VoIP Problemso Management Requirementso Common Metrics proposalo Media path reportingo Reporting through signaling

protocolso RTCP XRo Applications examples

31-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

IP related problems

Gateway Gateway

Lost Packets

CODEC

Delay & Jitter

Packet discardsby jitter buffer

41-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Non-IP related problems

VoIPGateway

Hybrid

EchoCanceller Echo from

UnbalancedHybrid

Uncanceledecho

Signal Level tooHigh or low

51-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

VoIP Metrics Reporting

IP Endpoint

CallControl

IP EndpointMedia path

reporting

Signaling basedreporting

NetworkManagementreporting

61-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Signaling System Reporting

IP Endpoint

CallControl

End of call message

Voice over IP qualitymetrics

Integrates call quality data into CDR system, supports service management / billing

71-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Media Path Reporting

IP Endpoint

IP Endpoint

Media pathreporting

Allows information to be exchanged betweenendpointsAllows information to be sent through firewalls

81-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Management Reporting

IP Endpoint

ManagementSystem

SNMP“Get”

Provides access to informationon an “as needed” basisIntegrates with current NMS

91-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Common VoIP Metrics?

o Equipment needs only count/ measure one set of metrics regardless of the protocol used for reporting

o Network manager/ operator can see the same set of data regardless of how it was reported

o Drive the equipment vendors towards a common “sensible” metrics set

101-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

RTCP XR protocol

Loss rate Discard rate Burst density Gap density

Burst duration (mS) Gap duration (mS)

Round trip delay (mS) End system delay (mS)

Signal level RERL Noise level Gmin

R factor Ext R MOS-LQ MOS-CQ

Rx Config - Jitter Buffer Nominal

Jitter Buffer Max Jitter Buffer Abs Max

111-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

RTCP XR applications

GW

Provides several key functions:- Exchange information between endpoints to support more comprehensive call quality estimates- Allows mid-stream systems to monitor endpoint QoS, even if RTP payload encryption is used- Supports exchange of endpoint measured QoS where endpoint is in different management domain- Supports endpoint adaptation

121-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Migrating into signaling protocols

o RTCP XR – IETF AVT group• In RFC editor queue – RFC in October?• Already being implemented by

manufacturers

o H.323 …. H.460.9 Annex 2• Consent in January 2004?

o H.248 …. H.248.rtcpxr• Consent in January 2004?

o SIP ….. New work in IETF

131-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Generating VoIP Metrics

DSP

CODEC

“SoftwareProbe”

200 IPS

IP Phone or Gateway

RTCP XR

Loss/Discard

SignalNoiseRERL

End of CallSignaling

141-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Accumulating endpoint metrics in Gateway

SoftProbe

C”Q”DR

RTCP XR

SNMP orBulk upload

IP “cloud”

PCM

SNMP MIB based around RTCP XR metrics

151-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Example – IP Centrex

IP Network

Softswitch

Access linkcongestion

Poorly locatedserver

Passive hub orshared Ethernetsegments

LANcongestion

IP Phone

Service Providerdomain

NO VISIBILITYOF PROBLEMS

161-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Solution to IP Centrex problem

IP Network

Softswitch

Access linkcongestion LAN

congestionIP Phone

ManagementSystem

Real time reportingthrough RTCP XRprovides feedback on Service Quality

171-3 October 2003 Workshop on End-to-End Quality of Service. What is it? How do we get it?

ITU-T

Summary

o Equipment needs only count/ measure one set of metrics regardless of the protocol used for reporting

o Network manager/ operator can see the same set of data regardless of how it was reported

o Drive the equipment vendors towards a common “sensible” metrics set

o Already gaining support within the industry:• Nine+ test equipment vendors will be supporting

RTCP XR decodes by the end of 2003• At least three major IP equipment manufacturers

expected to be supporting RTCP XR by the end of 2003

• Three major DSP software vendors providing support for this architectural model by the end of 2003