Using Groovy to empower WebRTC Network Systems

Antón R. Yuste

@antonmry

Agenda● What is (and isn't WebRTC) ● Developing your own WebRTC service● Groovy & Network Systems● TADHack 2015

Once upon a time...

Forever

There was a time...● Where we use to see video by using plug-ins and external software ● Instant Messaging was delivered using the same concepts and Voice = Telephony● Suddenly everything changed

WebRTC @ Glance

WebRTC offers real time communication natively from a web browser

WebRTC @ Glance

WebRTC capable browser share, including

Mobile, Tablet and desktop

61 %

WebRTC @ Glance

WebRTC is a “MediaEngine” with

javascript API API

WebRTC @ Glance

WebRTC is a technology, NOT a solution,

AND open source projects too

So, what is WebRTC?

● A built-in application program interface that enables browser-to-browser applications for:

● voice calling

● video chat

● peer to peer of any data

● Media engine in the browser, accessed by JavaScript, downloaded from web-server.● Collaborative W3C and IETF standardization

The WebRTC tree

IMS, LTE

WWW

VoIP

So, what is WebRTC - Technically Speaking?

PEER CONNECTION

(AUDIO, VIDEO, DATA)

WEB SERVER

(WEBRTC CONTROL)

GATEWAY

PEER CONNECTION

(AUDIO, VIDEO, DATA)

PEER CONNECTION

(AUDIO, VIDEO, DATA)

WEB SERVER

(WEBRTC CONTROL)

What isn't WebRTC - Technically Speaking?

● No MTI coded media● No defined signaling mechanism

It's a Standard Specification and an

opensource project

Signaling – The Two Approach

SIP over WebSockets JSON over WebSockets

Why JSON, XMPP, * and not SIP? ● Much more easy ● There are more developers ● Language of the web● And it’s natively supported by browser● Drives more SIP into the network

WebRTC Browser Support: Desktop

WebRTC Regional Browser Support: Desktop

A new Sheriff in town ● August 20, 2014. Microsoft published a blog post publicly supporting the ORCT draft.

Browser support

WebRTC Browser Support: Mobile

Consideration

● Lack of WebRTC Support: ● SDK/library for Windows Phone and IOS devices

● Hardware support for Mobile Phone ● Software encoding & decoding will kill your battery for VP8

● New device will benefits from power processor● Snapdragon 800 4 ● nVidia Tegra 4

Where we are now?

Is WebRTC ready?

… and more!

Major WebRTC Standard APIs

Acquire audio/video

Communicate Media

Communicate Data

MediaStream/getUserMedia

RTCPeerConnection

RTCDataChannel

MediaStream

● Represents a stream of audio/video (stream from camera/mike)● Multiple Tracks ● Use navigator.getUserMedia()

MediaStream

var constraints = {video: true};function successCallback(stream) { var video = document.querySelector("video"); video.src = window.URL.createObjectURL(stream);}function errorCallback(error) { console.log("navigator.getUserMedia error: ", error);}navigator.getUserMedia(constraints, successCallback, errorCallback);

RTCPeerConnection

● Centre of WebRTC Standard API.

● Peer to Peer Communication● Codec, Security, bandwidth etc.

RTCPeerConnection

pc = new RTCPeerConnection(null);pc.onaddstream = gotRemoteStream;pc.addStream(localStream);pc.createOffer(gotOffer);

function gotOffer(desc) { pc.setLocalDescription(desc); sendOffer(desc);}

function gotAnswer(desc) { pc.setRemoteDescription(desc);}

function gotRemoteStream(e) { attachMediaStream(remoteVideo, e.stream);}

RTCDataChannel

● Arbitrary Data● File● Text● Games

● API Similar to WebSockets● Peer to Peer Data● Use SCTP

RTCDataChannel

var pc = new webkitRTCPeerConnection(servers, {optional: [{RtpDataChannels: true}]});

pc.ondatachannel = function(event) { receiveChannel = event.channel; receiveChannel.onmessage = function(event){ document.querySelector("div#receive").innerHTML = event.data; };};

sendChannel = pc.createDataChannel("sendDataChannel", {reliable: false});

document.querySelector("button#send").onclick = function (){ var data = document.querySelector("textarea#send").value; sendChannel.send(data);};

WebRTC Signaling

HTML App

Browser

HTML App

Browser

Session Description Protocol

Signaling? Signaling?

Media(RTCP/RTP)

Caller Callee

Session Description Protocol

WebRTC Offer/Answer Model

HTML App

Browser

HTML App

Browser

How ? How ?

Caller Callee

offer answer

ICE/STUN

Caller Calleemedia media

STUN

ICE/TURN

Caller Callee

media

STUN STUN

TURN TURN

The entire exchange in a complicated diagram

How to start using WebRTC API ?

Prerequisites

● Java 7● Maven 3.2+● Git● Your favorite IDE● Chrome browser● Internet Connection

Practice

git clone https://github.com/antonmry/SpringIOWebRTCSampleApp.git

ant jetty:run

Follow the mantra…● Java is Groovy, Groovy is Java.● Flat learning curve for Java developers, start with straight Java syntax then move on to a groovier syntax as you feel comfortable.● Almost 98% Java code is Groovy code, meaning you can in most changes rename *.java to *.groovy and it will work.

Template Engine maps messages in both

directions between applications and network

JSON TemplateEngine

SIP message

Application Network

Call

Flow

detail

Components and developer extension points

Template Engine configuration

PackageCriteria

Scripttemplate

Scripttemplate

Scripttemplate

Template Library

Criteria

Criteria

The Console Window

Package configuration

Inbound INVITE request

criteria

Inbound INVITE Request Template

TemplateContext passed as an argument

Using Script Library method

Creating a future task executed on successful ME response

Script Library

Groovy method specified in Inbound INVITE request template script

Groovy tips and tricks● Use “def” to declare variables and make them local: def b = "foo“.● Simplification of a getter method notation: def factory = context.webFactory // instead of context.getWebFactory()● Safe navigation operator (?.): def errorCode = context.webMessage?.header?.error_code● Check for a null object: if (context.webMessage?.payload?.sdp)

Groovy tips and tricks● Compile static @groovy.transform.CompileStatic (no dynamic types, compiles better and faster)● Iterators● ’as’ keyword● Closures● array and list operators * and *. – called ”spread” and ”spread-dot”● GPath – similar to xpath but runs on objects not xml

Groovy scripts troubleshooting● Add println statements and see output in the system out, e.g.: println “from=" + from● Use log4j and see output in wsc.log file, e.g. org.apache.log4j.Logger logger = org.apache.log4j.Logger.getLogger(getClass()) logger.info(“groovy info: from=“ + from)● When an exception is thrown within a Groovy script, a stack trace will be logged in the wsc.log file.

Groovy scripts troubleshooting

Groovy scripts troubleshooting

Caused by: groovy.lang.MissingPropertyException: No such property: sipReq for class: Script2 at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:50) at org.codehaus.groovy.runtime.callsite.PogoGetPropertySite.getProperty(PogoGetPropertySite.java:49) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callGroovyObjectGetProperty(AbstractCallSite.java:231) at Script2.pkg_register_dir_FROM_APP_typ_request_verb_connect_netsvc_default(Script2.groovy:705) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1085) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:952) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:909) at groovy.lang.Closure.call(Closure.java:411) at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.callGlobal(GroovyScriptEngineImpl.java:411) at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.callGlobal(GroovyScriptEngineImpl.java:405) at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.invokeImpl(GroovyScriptEngineImpl.java:394) ...

Groovy scripts validation

Example SIP Request Variable// Create REGISTER requestdef from = getFromAddress(context)def to = getToAddress(context)def sipReq = context.sipFactory.createSipRequest("REGISTER", from, to) // Set request URIsipReq.requestURI = context.sipFactory.createSipAddress(Constants.PROXY_SIP_URI).URI // Set contact userif (from.URI?.user) { sipReq.setContactUser(from.URI.user)} // Set sip.instance to allow container to use SIP Outbound// for routing purposes as defined in RFC 5626def sipInstance = "\"<urn:uuid:" + java.util.UUID.randomUUID() + ">\""sipReq.setSipContactParameter("+sip.instance", sipInstance)sipReq.setSipContactParameter("reg-id", "1")context.subSessionStore.put("sip.instance", sipInstance)sipReq.send()

GRUUs

A GRUU (Globally Routable User-Agent URI) is a SIP URI which

has a few properties.

?

Example SIP Request Variable

sipReq.setHeader("Supported", "gruu")// P-Charging-Vector exampledef icidValue = context.uniqueIddef myIp = java.net.InetAddress.localHost.hostAddresssipReq.setHeader("P-Charging-Vector", "icid-value=" + icidValue +";icid-generated-at=" + myIp)

Protecting System Performance

by Removing SIP Messages

if (sipResponse.status < 200) { // Ignore provisional responses} else if (sipResponse.status < 300) // Proceed with processing}{...}

Removing a SIP Header in a

Message

sipReq.removeHeader("headername")

Conditionally Passing SIP Headers

in Messages

def myWebParameter = context.webMessage?.header.?myParameterif (myWebParameter) { sipRequest.setHeader("MyHeader", myWebParameter)}

REST● Asynchronous and synchronous callback responses● Support for HTTP and HTTPS● Support for all standard REST methods● Support for REST calls during message processing or WebSocket connection establishment

Defining a REST URL Endpoint Constantpublic static final MY_REST_URL = "http://server:port/rest_endpoint"

Referencing the URL Constantdef restRequest = context.restClient.createRequest(Constants.MY_REST_URL...);

Creating a REST Request

def myRestRequest = context.restClient.createRequest(Constants.MY_REST_URL, "PUT");

Configuring a REST Request Object

myRestRequest.setAccept(APPLICATION_JSON);myRestRequest.setAcceptLanguage("en-us", "de-de", "fr-fr");myRestRequest.addHeader("My Key", "My Value");

Sending the REST Request

def xml = { mkp.xmlDeclaration() fish { name("salmon") price("10") }};

def myRestFuture = myRestRequest.send(xml, APPLICATION_XML);

Sending the REST Request

context.getTaskBuilder("processResponse").withArg("myRestFuture", restFuture) .onSuccess(restFuture).build();

context.getTaskBuilder("processResponse").withArg("myRestFuture", restFuture) .onError(restFuture).build();

REST Response Handler

void processResponse(TemplateContext context) { def result = context.taskArgs.restFuture.get() if (result.status == 200) { def fish = result.value() if (fish.name.text() == "salmon") { // Continue processing... } } else { // Handle any errors... }}

REST Authentication

def myRestAuthRequest = context.restClient.createRequest(Constants.MY_REST_URL, "PUT", true);def username = "myuserid";def password = [231, 245, 675, 232, 123] as byte[];myRestAuthRequest.setCredentials(username, password);

tadhack.optaresolutions.com

Add easily

telecom services

to your APPs

Industry-

standard SIP

servlet 2.0,

media control

and Java EE

Example SIP POJO (JSR-359)

@SipServletpublic class FooPOJO {

@Invite public void incomingCall(SipServletRequest request) { //... }

@Bye public void disconnectCall(SipServletResponse response) { //... }

}

WebRTC

Summary● WebRTC is a great option to implement or add Real Time Communication services.● Groovy is very good in network systems: it provides flexibility, easy to use and good performance● If you like communications & developing, don't miss TADHack 2015.

Q & A

Thanks!

@antonmry

www.

serviceandnetworkevolution.com