1. 乙太被動式光學網路上能支援多 媒體服務之動態頻寬配置機制 Dynamic Bandwidth Allocation Mechanisms for Multimedia Services on EPON 指導教授 : 吳和庭 博士 研究生：簡睿毅 日期 : 2005 / 7 / 15

2. Outline Background  Passive Optical Network (PON)  Ethernet Passive Optical Network (EPON)  Multi-Point Control Protocol (MPCP) Motivation Dynamic Bandwidth Allocation Scheme  IPACT & DBAM  DBA with QoS Simulation Result Conclusion & Future Work

3. Background The first mile still remains the bottleneck between high-capacity Local Area Networks (LANs) and the backbone network A new technology is required to an end- user over a single network  Inexpensive, Simple, Scalable  Delivering bundled voice, data, video services

4. Passive Optical Network ( PON ) A point-to-multipoint optical network Two primary types of PON technologies  ATM PON  EPON

5. PON Topology

6. Ethernet Passive Optical Network EPON started to be standardized by IEEE 802.3ah EFM since 2001 (2004 July done) Ethernet is a ubiquitous technology  Deployed widely in LAN, MAN and WAN Ethernet is more attractive to PON than ATM  High speed - up to 10 Gigabit/s  Lower cost  Easier interoperability

7. EPON Architecture

8. Features of EPON All data packets carried in EPON are encapsulated in Ethernet frames Broadcasting in the downstream direction from the OLT to ONUsdownstream Sharing the upstream channel capacity among ONUsupstream That is the problem !

9. Downstream

10. Upstream

11. Multi-Point Control Protocol The Multi-Point Control Protocol (MPCP) specifies a control mechanism between a Master unit and Slaves units connected to a Point-to-Multi-Point (P2MP) segment to allow efficient transmission of data MPCP is implemented in MAC Control layer MPCP uses five MAC Control messages  GATE, REPORT, REGISTER_REQ, REGISTER, and REGISTER_ACK

13. Motivation A dynamic bandwidth allocation scheme with a credit mechanism which can support QoS service and reduce packet delay

14. Dynamic Bandwidth Allocation Scheme IPACT  Interleaved Polling with Adaptive Cycle Time DBAM  Dynamic Bandwidth Allocation with Multiple Services DBA with QoS  Dynamic Bandwidth Allocation with QoS

15. IPACT Operation Step (1/4)

16. IPACT Operation Step (2/4)

17. IPACT Operation Step (3/4)

18. IPACT Operation Step (4/4)

20. Definition (1) EF  Expedited Forwarding ， High Priority AF  Assured Forwarding ， Medium Priority BE  Best Effort ， Low Priority

21. Definition (2)  The maximum bandwidth parameter of a specific class of traffic is determined by the SLA between the end user and service provider  the amount of data queued up in the buffer  is the requested bandwidth for class c traffic  the estimation credit

22. Waiting Time & Cycle Time

23. DBAM Operation

24. DBAM Case SLA Si EF:20 AF:30 BE:50 Request Ri EF:60 AF:20 BE:20 Credit Ci EF:70 AF:25 BE:25 EF:20 AF:25 EF:20 AF:25 BE:55 Assign Bandwidth = 100

26. Definitions  Actual queue size when transmission start  Finally guarantee bandwidth

27. Waiting Time & Cycle Time

28. DBA with QoS Operation(1/2)

29. DBA with QoS Operation(2/2)

30. DBA with QoS Case SLA Si EF:20 AF:30 BE:50 Request Ri EF:60 AF:20 BE:20 Credit Ci EF:70 AF:25 BE:25 Assign Bandwidth = 100 EF:20 AF:20 BE:20 Actual Queue Request Ai EF:65 AF:30 BE:25 Gi EF:20 AF:20 BE:20

31. Gi EF:20 AF:25 BE:25 Gi EF:50 AF:25 BE:25 Request Ri EF:60 AF:20 BE:20 DBAM Gi EF:20 AF:25 BE:55

32. Simulation Model EPON 的系統頻寬 1Gbps ONU 個數 16 封包大小 64~1518 Bytes 佇列大小 1 Mbytes 模擬時間 1秒1秒 系統負載 (Normalized Offer Load) 0~2 SLA 比例 EF-20% AF-30% BE-50% 封包產生方式 Poisson

33. Simulated Result (1)

34. Simulated Result (2)

35. Simulated Result (3)

36. Simulated Result (4)

37. Simulated Result (5)

38. Credit Consideration

39. Simulation Result (1)

40. Simulation Result (2)

41. Simulation Result (3)

42. Conclusion & Future Work Proposed a dynamic bandwidth allocation scheme can support QoS and reduce the packet delay for Ethernet Passive Optical Network Future Work : Credit consideration