A method for p2p streaming system join latency reduction using preferred peer lists
This presentation is the property of its rightful owner.
Sponsored Links
1 / 16

A Method for P2P Streaming System Join Latency Reduction Using Preferred Peer Lists PowerPoint PPT Presentation


  • 46 Views
  • Uploaded on
  • Presentation posted in: General

A Method for P2P Streaming System Join Latency Reduction Using Preferred Peer Lists. Jeonghun Noh Sachin Deshpande* Information Systems Laboratory Stanford University * Sharp Laboratories of America. Toward Low Latency P2P Video Streaming. Real-time video streaming is time-sensitive.

Download Presentation

A Method for P2P Streaming System Join Latency Reduction Using Preferred Peer Lists

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


A method for p2p streaming system join latency reduction using preferred peer lists

A Method for P2P Streaming System Join Latency Reduction Using Preferred Peer Lists

Jeonghun Noh

Sachin Deshpande*

Information Systems Laboratory

Stanford University

* Sharp Laboratories of America


Toward low latency p2p video streaming

Toward Low Latency P2P Video Streaming

  • Real-time video streaming is time-sensitive.

    • Users prefer quick video play-back.

    • Channel surfing benefits from a short join latency.

  • Join latency in P2P systems

    • During join procedure, new peers connect to peers in the system to receive video.

    • Existing P2P networks: new peers blindly probe for parents at random.

GOAL: Design a P2P network that provides

a small join latency


Overview

Overview

  • Preferred Peers List System

    • Overview

    • Preferred Peer Cache/List

    • Parent switching

    • Soft Handover

  • Experimental Results

  • Conclusions


Overview preferred peer list system

Overview: Preferred Peer List System

  • Preferred Peer Cache (PPC)

    • Caches information about available peers (preferred peers) in the overlay.

    • Maintained by the source peer

  • Preferred peers have a high probability of being available to other peers

  • Using PPC for peer recommendations

    • New incoming peers contact the source peer.

    • The source peer sends a Preferred PeerList (PPL) containing preferred peers.

    • The new peers directly contact the preferred peersto connect to.


Partial learning of the overlay

PX

PY

Partial Learning of the Overlay

  • Source peer partially learns about the overlay from the peer’s join / leave reports

S

X

Y

JOIN Report

LEAVE Report


Using the knowledge about the overlay

Using the Knowledge about the Overlay

  • A list of peers, PPL, is created when a recommendation is requested from new peers.

  • Among the most recently updated peers, peers recommended less often are chosen.

Peer address | Use-count | Update time (in secs)

PPC

(at the source)

Selected peers


Join p rocedure using ppl

Video stream

Join Procedure Using PPL

Initial join request

  • Contact video source

  • Receive number of trees, video rate

  • Receive flat list, preferred peer list (PPL)

Direct connection and peer probe

  • Contact preferred peers on PPL

  • Probe peers on flat list

Use probe replies;

if preferred peer attempt fails.

  • Selects best parent from probe replies

  • Parent selection factor

    • Available bandwidth

    • Minimize tree height


Parent switching

Parent Switching

  • Preferred peer recommendations do not guarantee the best parents

  • One method to choose better parents

    • Utilize collected probe replies

    • Perform the probe-based join process


Distribution tree at time 71s

Distribution Tree at time 71s

No Parent Switch

: video source

: peer in the session

: peer that left the session

Average Tree Height : 3.76

Average PSNR : 39.71dB


Distribution tree at time 71s1

Distribution Tree at time 71s

Parent Switch

: video source

: peer in the session

: peer that left the session

Average Tree Height : 2.67

Average PSNR : 40.13dB


Soft handover

Soft Handover

  • Parent switching may cause video discontinuity.

  • Using Soft Handover

    • Keep old and new parents simultaneously so that both parents forward video packets.

    • As soon as duplicate packets are detected, send leave message to old parent.


Experimental s etup

Experimental Setup

  • Network simulation in ns-2

    • 75 / 300 active peers

    • Random peer arrival/departure average: ON (90 sec)/OFF (10 sec)

    • Peer uplink: typical access bandwidth / uniform bandwidth

  • Video streaming

    • Mother & Daughter sequence encoded with H.264/AVC @ 281 Kb/s (CIF quality)

    • 15-minute live multicast

  • System constructs 4 complimentary multicast trees.


Distribution of join latency

Distribution of Join Latency

  • Comparison of join time distribution

    • PPL system versus a probe-based system

    • Influence of peer uplink bandwidth: heterogeneous / uniform distributions

First tree join time

Full connection time


Effects of parent switching

Effects of Parent Switching

  • Simulation setup: 500 secs, uniform bandwidth distribution for peer uplink

  • PSNR averaged over 10 simulations and 75 peers


Effects of soft handover

Effects of Soft Handover

  • Observations

    (+) Up to 55% of redundant packet forwarding is reduced

    (-) Slight PSNR drop may occur


Conclusions

Conclusions

  • PPC keeps partial information about the P2P overlay system.

  • Preferred peers are selected from incomplete PPC.

  • One step closer to low-latency P2P video streaming:

    • New peers can join faster.

    • By switching parent after PPL-based direct attach, overlay quality is improved.

    • By Soft Handover, up to 55% of redundant video packet transmission can be avoided.


  • Login