1. The 7th CJK NGN Working Group Meeting October 10 ~ 11, 2006, Tokyo, Japan Performance Objectives for performance testing on CJK NGN testbed Hyungsoo Kim (hans9@kt.co.kr)

2. The 7th CJK NGN Working Group Meeting 2 1. Why? 2. Problem statements 3. Study plan 4. Further consideration Contents

3. The 7th CJK NGN Working Group Meeting 3 1. Why? The purpose of performance testing (Scenario 6) is to evaluate a service would be achieved the required performance level. The required performance level (objectives) should be identified. Some performance parameters have been discussed in Testbed Group : delay, delay variation, loss, etc. ITU-T Recommendations could be referred. i.e., Y.1541 ( Network performance objectives for IP-based services) Performance Parameter Nature of Network Performance Objective Class 0Class 1Class 2Class 3Class 4Class 5Class 6Class 7 IPTD Upper bound on the mean IPTD 100 ms400 ms100 ms400 ms1 sU100 ms400 ms IPDV Upper bound on the 1-10 -3 quantile of IPTD minus the minimum IPTD 50 ms UUUU IPLR Upper bound on the packet loss probability 1*10 -3 U1*10 -5 IPERUpper bound1*10 -4 U1*10 -6

4. The 7th CJK NGN Working Group Meeting 4 2. Problem statements Table of Y.1541 refers to Service Level Requirements, independent of actual distance and number of links. At least 2 references are existing; TTC & TTA for VoIP service requirements End-to-end delay of Class A (TTC) : ~ 100 ms End-to-end delay (TTA) : ~ 150 ms If the path under test covers from Seoul, Korea to Tokyo, Japan, and the performance testing result shows around 200 ms (90 ms of Japan side & 110 ms of Korea side), is it good quality ? Y.1541 QoS class 0,2 & 6 < 200ms < TTC class C CJK NGN testbed will cover the distance from Japan to China through Korea. (currently, from China to Korea) A note of Table 1 of Y.1541 introduces as follows : In some other circumstances (i.e., longer than 5000 km distance), the IPTD objectives in Classes 0, 2 and 6 will not always be achievable.

5. The 7th CJK NGN Working Group Meeting 5 3. Study Plan The study considers various approaches toward achieving end-to-end (UNI- UNI) IP network performance objectives. ① Analysis and choice of approaches; pros and cons ② Identification of distance for an end-to-end test path on CJK NGN testbed ③ Calculation of actual performance objectives for performance testing on CJK NGN testbed Allocation rules of ITU-T Recommendation Y.1542 could be referred for this purpose - Framework for achieving end-to-end IP performance objectives Y.1542 recommends quite many approaches ; - Static - Pseudo-static - Signaled - Impairment accumulation Which approach should be applied?

6. The 7th CJK NGN Working Group Meeting 6 4. Further considerations The real environment of CJK NGN testbed should be recognized. Relationship with national requirements in each countries’ policy should be taken into account. Cooperation and coordination among 3 countries’ organizations (TTC, CCSA and TTA) is needed. The international VoIP service requirements (i.e., service license) may be considered. Performance allocation among providers on nation-wide may be studied.