IVR Presentation

IVR PresentationIVR Presentation

Topic:A peer-to-peer message exchange scheme for large scale networked virtual environment. (N19)

Presented by Feng SHEN, u3390679

Content tableContent table

Some keywordsBackground of this paperPeer-to-peer message exchange schemeSimulationQuestions

KeyworkdsKeyworkds

Net-VE: Networked Virtual EnvironmentP2P: Peer-to-peerS/C: Server/Client architectureAOIM: Area of Interest Management

BackgroundBackground

2002, multi-user based game & application become a big business

Increase of user numberRequire high performance hardware &

complex software systems

MMORPG in 2002MMORPG in 2002

EverQuest holds 400,000 registered usersInteract in one consistent VE in real-timeBig challenge for system scalabilityDominant factor affects scalability

-- the way to exchange updated message

Solution in 2002Solution in 2002

To solve the problem, many communication architectures are proposed

Peer-to-peerServer/client architecture

P2P architectureP2P architecture

Unicast– O(N2) for N entities– bad performance for large N

Multicast combined with area partioning scheme– works well, but multicast not widely

avaliable on the Internet

Server/ClientServer/Client

Entity Server entitiesServer – bottleneckFailure of server = failure of whole systemMulti-server/client

* Over-provision

* Estimate no of entities

* Too costly for large-scale applications

Proposal of this paperProposal of this paper

Scalable p2p message exchange schemePeer-to-peer architecture No multicast infastructureNo centralized mechanism

Details of schemeDetails of scheme

A. Bootstrap methodB. Creating overlay network

– Each entity connects neighbouring entities– Scheme keeps latency smaller than S/C

architecture– Network deployed without multicast

infastructure

AA. Bootstrap method. Bootstrap method

Procedure for an entity enters VE for the first time

This entity acquire information of other entities already in VE

BB. Creating overlay network. Creating overlay network

Entity acquire surrounding entities Classify into two groups AE & LE

– AE: Active entities, direct interacation, detail information

– LE: Latent entities, potiential interaction, rough information

Take the nearest N entities as AE Unicast connects AE

Exchange messageExchange message

Information of AE exchanged through unicast connection

Information of LE– Each entity compress its AEs’ rough information into

list– Exchange this list with its AEs’ lists– Knows LE’s location

They should recognize each other, establish direct connection, set AE

SimmulationSimmulation

Key issue of creating Neted VE – to keep optimal adjacency relationship of

entities in VE

Compare result with that from S/C schemeShow scalability & performance

S/C entity processorS/C entity processor

1. Calculates the entities location at time T2. Calculates the distance among all the

entities to generate a distance table3. According to the table, inform the nearest

N entities of each entity as Active Entity

P2P entity processorP2P entity processor 1.Updates the location of entity “I” (Entity(I)) at time T 2.Inquire its neighboring entities (Entity(I).AE(J))

about their current locations 3.Then inquire the neighboring entities about the

information of their neighboring entities (Entity(Entity(I).AE(J).ID).AE(K)))

4.Calculates the distance among the entities based on the information acquired in the previous step and sort them in order of the distance

5.Set the nearest N enteritis as new Active Entities

Qualitative analysisQualitative analysis

Two models resemble each other To evaluate quantitatively, define

N: the no of entities in VEP(I): the no of AEs for entity I in P2P modeQ(I): the no of AEs for entity I in S/C mode

ConsistencyConsistency

The P2P based message exchange scheme makes it possible for entities to establish almost consistent relationship (>0.9) compared to S/C scheme, independently of the number of the participants in the virtual environment.

This scheme scales well.

ConclusionConclusion

The proposed P2P message exchange scheme can build consistent virtual environment in a scalable manner.

Questions?Questions?