Peer-to-peer Multimedia Streaming and Caching Service

Jie WEI, Zhen MA

May. 29

Outline Metrics For Multimedia Streaming Non P2P Solution Peer to Peer Solution Architecture Caching Streaming Conclusion

Metrics For Multimedia Streaming Low initial Delay

Small Delay Jitter During Playback

Minimum network bandwidth utilization

Non P2P Solution Caching and Pre-fetching by Media

Gateway Achieve small initial delay and delay

jitter during playback Broadcasting Services

Achieve minimum server network bandwidth utilization

Motivation For P2P Architecture Motivation of the peer-to-peer

architecture Exploits the proximity of clients Minimizes the bandwidth utilization between

the server and group of clients Architecture

Assumes the group of peer-to-peer clients is connected via LAN

Each client not only receives streams from the server, but also acts as a proxy server.

Architecture One server,one cache manager and four nodes s(i,j) represents segment of stream between byte i and j

S(0,t4)

S(0,t1)S(t3,t4)

S(t1,t2)C1

C2

C3

Cx

S

Cache Manager

Caching Management Each client caches the retrieved

stream and publishes its cache information to the cache manager

Each client monitors its own resource availability (eg. network bandwidth), updates all information to the cache manager

Streaming Cache lookup

Send query message to cache manager for information of cached streams in peer clients

Streaming and Pre-fetching With response from the cache

manager, the client send streaming and pre-fetching requests to the peer clients or the server

Streaming Timing diagram of the streaming

and pre-fetching (requested by Ci)

Streaming Switching In order to minimize the switching

delay jitter, we should ensure a proper pre-fetching time

The pre-fetching time t is determined by,

Network bandwidth B Network delay D

Pre-fetching Time Case 1: B is larger than requested

service rate, we only need to care about the network delay to ensure proper pre-fetching

Case 2: B is smaller than , Buffer underflow might happen. We need to consider both network bandwidth and delay to ensure proper pre-fetching

How it achieves the metrics Low initial Delay?

Small Delay Jitter During Playback?

Minimum network bandwidth utilization?

How it achieves the metrics Low initial Delay By requesting to a peer client in

the peer group, which caches the initial segments, it lowers initial delay than always requesting directly to the distant server

How it achieves the metrics Small Delay Jitter During Playback? Minimize the switching delay jitter

by calculating the right time point to do enough pre-fetching

How it achieves the metrics Minimum network bandwidth

utilization? P2P architecture reduces network

bandwidth utilization and stream transfer time in the Client-Server architecture

Conclusion Discussed a P2P Multimedia

Streaming and Caching Model

P2P Multimedia Streaming and Caching Service can improve performance in all the three metrics.

Thank you