Mixed P2P-CDN System for

Media Streaming in Mobile Environment

Speaker: Shao-Ci JhengAdvisor: Dr. Ho-Ting Wu

2014/05/05

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Outline Introduction Mixed CDN-P2P Network Architecture Peer schedule Algorithm of

Mixed CDN-P2P System Performance Evaluation Conclusion References

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Introduction — P2P Peer-to-Peer , P2P Architecture : decentralized

and distributed Peers both suppliers and

consumers of resources

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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.

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Introduction — CDN Content Distribution Network ,CDN Architecture : distributed system , Server-

Client Large distributed system of servers deployed

in multiple data centers across the Internet.

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Introduction — CDN(Cont.)

Advantages DisadvantagesIncrease in the number of concurrent users

Impractical for many organizations

Decrease the server load High costFaster content delivery Support100 percent availability MaintenanceMore control of asset delivery Verification of the best locations

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Mixed CDN-P2P Network Architecture

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Mixed CDN-P2P Network Architecture(Cont.)

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Mixed CDN-P2P Network Architecture(Cont.)

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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.

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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.

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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.

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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.

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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.

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

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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)

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Performance Evaluation(Cont.)

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Performance Evaluation(Cont.)

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References Shiann-Tsong Sheu , Dept. of Commun. Eng, Jhongli , Chi-Hao

Huang,” Mixed P2P-CDN System for Media Streaming in Mobile Environment”, 2011 7th International on Wireless Communications and Mobile Computing Conference (IWCMC), 4-8 July 2011,pp. 657 – 660

Wiki,URL : http://en.wikipedia.org/wiki/Peer-to-peerURL :

http://en.wikipedia.org/wiki/Content_delivery_network

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Thank you for listening.