P2P on the local network

P2P on the local network
getting your devices to play together

Peter Elst - Project Cocoon Multimedia - FFK11 April 6th 2011

What will we talk about?

‣ What is P2P and how does it work?



‣ How can you set up P2P with Flash Player and AIR?




‣ What are the use cases for P2P?





‣ Examples and technical walkthrough





‣ Examples and technical walkthrough

‣ Questions & answers

What is P2P?

‣ P2P enables direct communication between clients

What is P2P?


‣ Clients register themselves, from there on all communication
happens directly between connected clients

What is P2P?



‣ Huge decrease in bandwidth requirements

What is P2P?



‣ Huge decrease in bandwidth requirements

‣ You can do P2P communication without a server (!)

Traditional network setup

‣ Centralized communication



‣ Single point of failure




‣ Bandwidth needs increases with
each additional client




‣ Bandwidth needs increases with
each additional client

‣ Not extremely scalable

P2P network setup

‣ Decentralized communication

P2P network setup


‣ More robust network setup

P2P network setup



‣ Additional clients makes
network faster

P2P network setup



‣ Additional clients makes
network faster

‣ Easily scalable solution for
multi-user applications

P2P concepts

‣ NetGroup - P2P channel through which you communicate

P2P concepts


‣ Peer ID - unique identiﬁer given to each connected client

P2P concepts



‣ Posting - sending a message to clients in a netgroup

P2P concepts




‣ Routing - sending a message to a client via neighbor peers

P2P concepts




‣ Routing - sending a message to a client via neighbor peers

‣ Object replication - transferring of data using chunks

How do you set up P2P?

‣ Create a NetConnection instance



‣ Connect to an RTMFP server (if wanted)




‣ Specify a GroupSpeciﬁer and NetGroup instance





‣ Listen for neighbor connect and disconnect events






‣ Post message to NetGroup or route through nearest neighbor






‣ Post message to NetGroup or route through nearest neighbor

‣ Handle ﬁle chunks for object replication

The boilerplate code 1/2
nc = new NetConnection();
nc.addEventListener(NetStatusEvent.NET_STATUS, onNetStatus);
nc.connect("rtmfp:");


gSpec = new GroupSpecifier("myNetGroupID");
gSpec.postingEnabled = true;
gSpec.routingEnabled = true;
gSpec.ipMulticastMemberUpdatesEnabled = true;
gSpec.objectReplicationEnabled = true;
...
gSpec.addIPMulticastAddress("225.225.0.1:30303");


gSpec = new GroupSpecifier("myNetGroupID");
gSpec.postingEnabled = true;
gSpec.routingEnabled = true;
gSpec.ipMulticastMemberUpdatesEnabled = true;
gSpec.objectReplicationEnabled = true;
...
gSpec.addIPMulticastAddress("225.225.0.1:30303");

group = new NetGroup(nc, gSpec.groupspecWithAuthorizations());
group.addEventListener(NetStatusEvent.NET_STATUS, onNetStatus);

private function onNetStatus(evt:NetStatusEvent):void {
switch (evt.info.code) {
case "NetConnection.Connect.Success":
// netconnection successful
break;
case "NetGroup.Neighbor.Connect":
// client joined the netgroup
break;
case "NetGroup.Neighbor.Disconnect":
// client left the netgroup
break;
case "NetGroup.Posting.Notify":
// message was posted to the netgroup
break;
...
}
}

Mobile clients - AIR for Android


‣ AIR for Android allows us to run desktop AIR ﬁles and take
advantage of additional mobile speciﬁc features such as the
accelerometer, geolocation,...



‣ Almost all desktop APIs are supported



‣ Almost all desktop APIs are supported

‣ Its a lot of fun to develop for!

Mobile clients - compiling to iOS


‣ AIR can cross-compile to native iOS binaries



‣ Apple started allowing third party cross-compiled applications
back into their app store



‣ Apple started allowing third party cross-compiled applications
back into their app store

‣ Compiled binaries generally have a larger ﬁle size

Accelerometer API
if(Accelerometer.isSupported) {
var acc:Accelerometer = new Accelerometer();
acc.setRequestedUpdateInterval(500);
acc.addEventListener(AccelerometerEvent.UPDATE, update);
}

private function update(evt:AccelerometerEvent):void {
trace("x acceleration: "+evt.accelerationX);
trace("y acceleration: "+evt.accelerationY);
trace("z acceleration: "+evt.accelerationZ);
}

Geolocation API
if(Geolocation.isSupported){
var geo:Geolocation = new Geolocation();
geo.setRequestedUpdateInterval(10000);
geo.addEventListener(GeolocationEvent.UPDATE, update);
}

private function update(evt:GeolocationEvent):void {
trace("latitude: "+evt.latitude);
trace("longitude: "+evt.longitude);
trace("speed: "+evt.speed);
}

Use cases - Gaming

‣ Sensor data can turn any device into a game controller

Use cases - Gaming


‣ High scores and other game data can be synchronized and
persisted on the mobile device

Use cases - Gaming


‣ High scores and other game data can be synchronized and
persisted on the mobile device

‣ Practically everyone carries a phone so can immediately join in

Use cases - E-Learning

‣ Students are increasingly using devices for their studies



‣ Connected class rooms with shared whiteboards and
collaborative tasks



‣ Connected class rooms with shared whiteboards and
collaborative tasks

‣ Teachers can get realtime data and statistics on how their
students perform on particular exercises

Use cases - Sensor input

‣ Mobile devices can provide additional input to your computer



‣ Software can take advantage of multi-touch, accelerometer,
geolocation data and camera access



‣ Software can take advantage of multi-touch, accelerometer,
geolocation data and camera access

‣ Mobile device becomes a second screen and helps with your
productivity

Introducing Cocoon P2P
‣ Simple open source library focussed on
local IP multicast with Flash Player 10.1
or later and AIR across devices


‣ Very easy to use, avoid boilerplate code


‣ Very easy to use, avoid boilerplate code

‣ Early support for ﬁle transfer, video
streaming and accelerometer

cocoon-p2p.googlecode.com

Example - device discovery

<p2p:LocalNetworkDiscovery id="channel" clientName="FFK11 - beyond tellerrand" /
>

<s:List width="80%" height="200"
horizontalCenter="0" verticalCenter="0"
dataProvider="{channel.clients}" labelField="clientName" />

Example - messaging

<p2p:LocalNetworkDiscovery id="channel"
clientAdded="onClientAdded(event)"
clientRemoved="onClientRemoved(event)"
dataReceived="onDataReceived(event)"
loopback="true" />

channel.sendMessageToAll("Hello everyone!");
channel.sendMessageToClient("Hello you!", peerID);

Example - photo sharing

dataReceived="onDataReceived(event)"
fileComplete="onFileComplete(event)" />

var myFile:File = File.desktopDirectory.resolvePath("image.jpg");

channel.sendFileToAll(myFile);
channel.sendFileToClient(myFile, peerID);

Example - multiplayer game

• <p2p:LocalNetworkDiscovery id="channel"
accelerometerInterval="1000" />

accelerometerUpdate="onAccelerometer(event)" />

private function onAccelerometer(evt:AccelerometerEvent):void {
trace("x acceleration: "+evt.accelerationX);
trace("y acceleration: "+evt.accelerationY);
trace("z acceleration: "+evt.accelerationZ);
}

Example - video streaming

• <p2p:LocalNetworkDiscovery id="channel"
videoStream="{cam}" />

var cam:Camera = Camera.getCamera();

var video:Video = new Video(320,240);
video.attachCamera({channel.videoStream});

Security dialog

‣ Everything covered here does not require Adobe AIR

Security dialog


‣ Using P2P in Flash Player will prompt a security dialog

Security dialog



‣ User can control whether or not
to allow peer assisted networking

Security dialog



‣ User can control whether or not
to allow peer assisted networking

‣ For AIR applications this is allowed
by default without user interaction

Summary

‣ P2P is available from Flash Player 10.1 onwards and in Adobe
AIR across devices (including iOS, BlackBerry PlayBook,
Google TV,...)

Summary

Google TV,...)

‣ You can use this feature for connecting local devices without
the need for a Flash Media Server

Summary

Google TV,...)

‣ You can use this feature for connecting local devices without
the need for a Flash Media Server

‣ Devices need to be on the same wiﬁ network and IP multicast
must not be blocked on the router

Resources

‣ Tom Krcha - ﬂashrealtime.com

Resources


‣ HydraP2P - github.com/devboy/HydraP2P

Resources


‣ HydraP2P - github.com/devboy/HydraP2P

‣ Cirrus (formerly Stratus) - labs.adobe.com/technologies/cirrus

Questions?

Peter Elst

e-mail info@peterelst.com
twitter @peterelst
blog www.peterelst.com
company www.project-cocoon.com

Thank you!

Peter Elst

e-mail info@peterelst.com
twitter @peterelst
blog www.peterelst.com
company www.project-cocoon.com

P2P on the local network

More Related Content

What's hot (18)

Viewers also liked (20)

Similar to P2P on the local network (20)

More from Peter Elst (17)

Recently uploaded (20)

P2P on the local network

Editor's Notes