1 Buddy Internet Exchange LYU0701 Supervisor: Professor Michael R. Lyu Prepared By: Kwong Kwok Wai Chan Kwan Ho

2 Review of first term Focus on the transport-layer : Application independent Network topology discovery could have further benefits to P2P applications

3 Motivation Hong Kong is in the progress of switching to High Definition TV Broadcast Current coverage is not complete Most recorders could not record two channels simultaneously High bandwidth requirement to transfer over the Internet

4 Objective Build an easy-to-use TV scheduler Share the TV contents to those who are eligible to watch but not able to receive HDTV signals. Design a high-speed transfer protocol to optimize the total waiting time and the maximum waiting time

5 Set-Top Box A device to decode digital TV signal. Equipped with network capabilities. Could record TV programs into a hard disk Not programmable by 3 rd party, so we will simulate it using PC.

6 Client Application

7 Network Architecture Client / Server Model Fully Decentralized Model Hybrid Decentralized Model – Efficient peer discovery – Bottleneck at peers only – Minor drawbacks The network formation of a hybrid decentralized model

8 Client Application Probe network connection speed for path determination Probe network port connectivity

9 Client Application Easy-to-use GUI for HDTV recording schedule Provides EPG for the coming week in form of XML

10 Client Application Records the HDTV program if hardware is available (not implemented) Forms a P2P network as instructed by server. Transfers HDTV contents

11 BIX sharing network formation algorithm

12 Algorithm design Goal – Smallest total waiting time (Main Idea) – Smallest maximum waiting time Cannot obtain both when huge number of ADSL users.

13 Algorithm design Sorting peers – 1st type causes of bottleneck – 3rd type is not efficient in sharing – Priority of 2nd type > 3rd type > 1st type

14 Algorithm design Sorting peers Variances = with pi = 1, Xi = priority, mean = 0 priority = where x = priority priority = priority * (user[uplink]) 1/2

15 Algorithm design Peers selection – Inter Peers Network Status Matrix (IPNSM)

16 Algorithm design Peers selection – In order of sorted list – Find the highest output node using IPNSM – Update IPNSM

17 Algorithm design Utilize non optimal link – Travel starts from leaf node – Connect to non optimal node in higher level

18 Algorithm design Inter ISP policy – Rules applied on non-reserved port – Upload bandwidth limit on fan out number HKBN – Fan-out = 1, Output = MAX – Fan-out = 2, Output = MAX/2 – Fan-out >= 3, Output = MAX/4 -HGC – Fan-out = 1, Output = MAX – Fan-out >= 2, Output = 310kb/s – Solution Limit the number of connection to different ISP peer to 1

19 Test Result Compare with Bit Torrent (BT) Each test is done for 5 times Equipment: – 6PC – 2HKBN, 2HGC, 2PCCW

20 Test Result Case 1: Sharing 100MB video file. Source: HKBN BB25 Total waiting time of BIX: 9m 45s Total waiting time of BT: 17m 54s Maximum waiting time of BIX: 3m 52s Maximum waiting time of BT: 6m 14s

21 Test Result Case 4: Sharing 2GB video file. Source: HKBN BB25 Total waiting time of BIX: 3h 14m 46s Total waiting time of BT: 4h 25m 2s Maximum waiting time of BIX: 1hr 16m 8s Maximum waiting time of BT: 1h 25m 56s

22 Test Result Overall result 100MB file600MB file Maximum waiting time Total waiting timeMaximum waiting time Total waiting time BIX3m 52s9m 45s23m 12s58m 26s BitTorrent (BT)6m 14s17m 54s28m 45s1h 18m 55s Difference in %61.1%75.03%23.92%34.64% 1GB file2GB file Maximum waiting time Total waiting timeMaximum waiting time Total waiting time BIX38m 53s1hr 37m 50s1hr 16m 8s3h 14m 46s BitTorrent (BT)48m 8s2h 11m 40s1h 25m 56s4h 25m 2s Difference in %23.79%34.56%26.01%36.08

23 Explanation BitTorrent has a solution for optimal path – Add information header Huge overhead, consume processing power – Exchange groups of peers Takes times, and may not be optimal Inter ISP policy – Connected every peers Fan-out to different ISP is large

24 Conclusion BIX has better performance than BT Functional: – Better path – Concern of ISP policy Non-functional: – CPU usage – Setup time

25 Future development

26 HDTV Content Reduction 6GB for 1 Hour of HDTV content Around 20% are commercials Channel logo determines if it is a commercial

27 HDTV Services TiVo is a leader in TV services – Automatic recording scheduler – Real-time TV pause – Large volume hard disk for long playback Easy to mimic More advantage to share through internet No legal issues ( ReplayTV )

28 Q & A