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End to End Quality of Service. Paul Coverdale Nortel Networks Tel: +1 613 763 4277 Email: paulcov@nortelnetworks.com. End to end QoS. everybody talks about it what does it mean ? how do we get it ?. QoS-enabled Domain 1. QoS-enabled Domain 2. QoS-enabled Domain n.
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End to End Quality of Service Paul Coverdale Nortel Networks Tel: +1 613 763 4277 Email: paulcov@nortelnetworks.com
End to end QoS • everybody talks about it • what does it mean ? • how do we get it ? GSC-8, OTTAWA
QoS-enabled Domain 1 QoS-enabled Domain 2 QoS-enabled Domain n Bottom-up approach to end to end QoS • lots of attention on mechanisms and protocols for enabling QoS in individual IP domains • these mechanisms drive resulting end to end QoS • not clear on benefit to end-user End to end QoS required by user (QoE) GSC-8, OTTAWA
QoS-enabled Domain 1 QoS-enabled Domain 2 QoS-enabled Domain n Top-down approach to end to end QoS • focus on customer (the one who pays the bill) • understand end-user expectations for QoS • Quality of Experience (QoE) • use these to drive requirements for specific QoS mechanisms for individual domains End to end QoS required by user (QoE) GSC-8, OTTAWA
Packet Loss Interactive Responsive Timely Non-critical 5% Conversational voice and video Voice/video messaging Streaming audio/video Delay 100 msec 1 sec 10 sec Fax 100 sec 0% Command/ control (eg Telnet, Interactive games) Transactions (eg E-commerce, Web-browsing, E-mail access) Messaging, Downloads (eg FTP, still image) Background (eg Usenet) Zero loss End-user requirements • wide range of user requirements, depending on application From ITU-T Rec. G.1010 GSC-8, OTTAWA
QoS Classes Network Class 0 Class 1 Class 2 Class 3 Class 4 Class 5 Performance Un- Parameter specified Transfer delay 100ms 400ms 100ms 400ms 1 s U Delay variation 50ms 50ms U U U U -3 -3 -3 -3 -3 Packet loss ratio 1*10 1*10 1*10 1*10 1*10 U -4 Packet error ratio 1*10 U Network QoS Classes • no need to try to meet specific QoS requirements for each application • provide several network QoS classes to carry traffic having broadly similar requirements From ITU-T Rec. Y.1541 GSC-8, OTTAWA
Implementing end to end QoS • two fundamentally different approaches • Internet model • Managed-Network model GSC-8, OTTAWA
QoS Signalling Call Signalling Internet model • intelligence remains at network edge • provides autonomy for end-points • but who is responsible for end to end QoS ? Application Plane Transport Plane Transport Domain 1 Transport Domain 3 Transport Domain 2 Bearer Traffic GSC-8, OTTAWA
QoS Signalling Call Signalling Managed-Network model • service provider able to control end to end QoS • but end-point tied to specific service provider Service Domain 2 Service Domain 1 Application Plane Transport Plane Transport Domain 1 Transport Domain 3 Transport Domain 2 Bearer Traffic GSC-8, OTTAWA
Standards Bodies addressing QoS • many Standards Bodies involved in QoS • IETF, ITU, ETSI, 3GPP, 3GPP2, IEEE, T1, MEF, etc • main focus on QoS mechanisms or on specific network elements (eg wireless or cable access) • achieving complete end to end QoS is clearly a Standards issue • need for better co-operation and co-ordination between Bodies to address end to end picture GSC-8, OTTAWA
Conclusions • need for recognition and reconciliation of different viewpoints on QoS • need for focus on the end-user • need for better coordination between Standards Bodies • ITU-T is well-positioned to take the leadership role • ITU-T Workshop on End to End QoS planned for Oct 1-3 2003 • Recommend GSC-8 should endorse a Resolution proposing ITU-T as prime Body for establishing global standards for end to end QoS GSC-8, OTTAWA