1. Mixed P2P-CDN System for Media Streaming in Mobile Environment
Speaker: Shao-Ci Jheng
Advisor: Dr. Ho-Ting Wu
2014/05/05

2. Outline Introduction Mixed CDN-P2P Network Architecture
Peer schedule Algorithm of
Mixed CDN-P2P System
Performance Evaluation
Conclusion
References

3. Introduction — P2P Peer-to-Peer , P2P
Architecture : decentralized and distributed
Peers both suppliers and consumers of resources

4. Introduction — P2P(Cont.)
Advantages
Disadvantages
No need for a network operating system
Slow down the performance for the user
Does not need an expensive server
Files and folders cannot be centrally backed up
No need for specialist staff
Files and resources are not centrally organized into a specific 'shared area'.
Much easier to set up than a client-server network
Ensuring that viruses are not introduced to the network is the responsibility of each individual user
If one computer fails it will not disrupt any other part of the network.
There is little or no security besides the permissions.

5. Introduction — CDN Content Distribution Network ,CDN
Architecture : distributed system , Server-Client
Large distributed system of servers deployed in multiple data centers across the Internet.

6. Introduction — CDN(Cont.)
Advantages
Disadvantages
Increase in the number of concurrent users
Impractical for many organizations
Decrease the server load
High cost
Faster content delivery
Support
100 percent availability
Maintenance
More control of asset delivery
Verification of the best locations

7. Mixed CDN-P2P Network Architecture

8. Mixed CDN-P2P Network Architecture(Cont.)

9. Mixed CDN-P2P Network Architecture(Cont.)

10. Peer schedule Algorithm mixed CDN-P2P System
CDN replica peer(CDN surrogate server)
Media content is divided into segments, and distributed across over all the replica peers.
The locations of each segment are maintained in a list stored in all of the CDN replica peers.

11. Peer schedule Algorithm mixed CDN-P2P System (Cont.)
Mobile peer sends request for playing media content to the nearest CDN replica peer.
CDN replica peer responses with a list of CDN replica peers that contains media content segments.

12. Peer schedule Algorithm mixed CDN-P2P System (Cont.)
RTT value between the mobile and CDN replica peers was measured before selecting the candidate peers of the first segment.

13. Peer schedule Algorithm mixed CDN-P2P System (Cont.)
The mobile peer sends control packet to the candidate peers and waited until a timeout occur.
If the first segment was able to receive within timeout, the process of requesting second segment starts immediately.

14. Peer schedule Algorithm mixed CDN-P2P System (Cont.)
When CDN replica peer 1 failed to transmit segment to the mobile peer within the timeout, the mobile peer replace failed replica peer with a CDN replica peer 4 as one of the selected candidates.
Control packet was sent out to the selected candidate peers. The CDN replica peer 2 was selected to transmit second segment to the mobile peer because it has the lowest RTT among the selected candidates.
The rest of media content segments follow the same procedures as previously described.

15. Peer schedule Algorithm mixed CDN-P2P System (Cont.)

16. Performance Evaluation
Bandwidth
Mobile download : 40Mbps
CDN replica peer : 100Mbps
Video
Type : MPEG
Length : 4000 sec
Each CDN replica peer(20)
Store Content : 50
Placed : round-robin(10)
Arrival rate : Poisson process
Popularities : Zipf-like distribution (α= 0.733)

17. Performance Evaluation(Cont.)

18. Performance Evaluation(Cont.)

19. References
Shiann-Tsong Sheu , Dept. of Commun. Eng, Jhongli , Chi-Hao Huang,” Mixed P2P-CDN System for Media Streaming in Mobile Environment”, th International on Wireless Communications and Mobile Computing Conference (IWCMC), 4-8 July 2011,pp. 657 – 660
Wiki,
URL :
URL :

20. Thank you for listening.