Windows Microsoft .Net Framework

Introduction to Zoiper SDK 2.0 Windows .Net Framework

This section explains how to develop your VoIP application with .Net Framework on Windows in combination with the Zoiper SDK 2.0 for Windows .Net. The SDK is an all-inclusive solution for developing VoIP applications for Windows with:

  • audio calls (SIP, IAX)

  • video call (SIP)

  • presence

  • messaging

  • call recordings

  • other functionalities

The SDK 2.0 consists of:

  • a dynamic library with all the respective headers in it

  • some helper libraries (e.g. LAME.dll).

Hardware and software requirements

Requirement Description
Processor Intel Core i3 or better
Memovy 4GB(minimum) 8 GB(recommended)
Hard disk space 1 GB
Environent Microsoft Visual Studio 2015 or newer
.Net Framework .Net Framework 4.5.2 or newer
Operating system (Development environment) Windows
Operating system (Runtime environment) Windows 8 or above
Architecture x86, x64

Contents of the SDK package

Folder Description
package/Documentation Contains the html Zoiper SDK Documentation. To open it in your browser, click on the index.html file.
package/RunTest Contains the Zoiper SDK dll and the additional library LAME.dll.
package/ZoiperWinForms Contains all files for the Demo application as well as its settings, properties etc.
package/ZoiperWinForms.sln The actual Demo project. To test Zoiper SDK 2.0, open, build and run the Demo application.

Setting up the Demo project

Default configuration

By default, the Demo application uses the transport type you select from the GUI. STUN is enabled with these default STUN settings:

  • Server: stun.zoiper.com

  • Port: 4378

  • Refresh period: 30s

  • Enabled codecs: u-Law, Opus Wide and VP8

Activation

You need an SDK activation to test the demo. Zoiper SDK 2.0 for .Net Framework offers both Online and Offline activation. #####Online Activation To activate the demo online, you need an activation username and password from zoiper.com. Pass your activation credentials in the application to the StartSDK() method as illustrated below:

//You will need to pass the activation credentials as certUserName and certPassword.
ctx.Activation.StartSDK("", certUserName, certPassword)

If the activation is successful, you will receive a result code “OK” from the StartSDK() method. You are now ready to test the Demo. In case the activation fails, the method will return a code with the reason for the failure.

#####Offline Activation Follow these steps to activate the demo offline:

  1. Generate a certificate

  2. Send it to register5@zoiper.com

  3. You will receive an activation file via email

  4. Put the activation file in the same directory as the project. Or pass it as a path to the file.

Beware! The first time you run the project and you call the activation, you must call the method to create an offline activation file - CreateOfflineActivationFileSDK(path, certUserName, certPassword) and pass the respective arguments. On the next start you just need to call the StartSDK(path + "\\certificate", certUserName, certPassword) method. Below, you can find a working example from the Demo application:

if (path != "" && countInits == 0)
{
	ctx.Activation.CreateOfflineActivationFileSDK(path, certUserName, certPassword);
    countInits++;
    return true;
}
else if (1 == countInits)
{
	ctx.Activation.StartSDK(path + "\\certificate", certUserName, certPassword);
    countInits--;
    return true;
}

Create and register your account

A complete example of the function that adds the user and its details is illustrated below:

public bool AddUser(Int32 transportType, String username, String password, String server, bool SRTP, bool ZRTP, bool FMTP , bool Privacy, bool Stun, bool Preconditions, bool RTCPFeedback, string protocol)
	{
		if (null == ctx)
        return false;
        Account account = ctx.AccountProvider.CreateUserAccount();

        account.AccountName = username;

        AccountConfig regCfg = ctx.AccountProvider.CreateAccountConfiguration();

        regCfg.UserName = username;
        regCfg.Password = password;

        if ("SIP" == protocol)
        {
			regCfg.Type = ProtocolType.SIP;
            regCfg.SIP = ctx.AccountProvider.CreateSIPConfiguration();

            if (ZRTP)
            {
            	var hash = new List<ZRTPHashAlgorithm>();
                hash.Add(ZRTPHashAlgorithm.s384);
                hash.Add(ZRTPHashAlgorithm.s256);

                var cipher = new List<ZRTPCipherAlgorithm>();
                cipher.Add(ZRTPCipherAlgorithm.cipher_aes3);
                cipher.Add(ZRTPCipherAlgorithm.cipher_aes2);
                ipher.Add(ZRTPCipherAlgorithm.cipher_aes1);

                var auth = new List<ZRTPAuthTag>();
                auth.Add(ZRTPAuthTag.hs80);
                auth.Add(ZRTPAuthTag.hs32);

                var keyAgreement = new List<ZRTPKeyAgreement>();
                keyAgreement.Add(ZRTPKeyAgreement.dh3k);
                keyAgreement.Add(ZRTPKeyAgreement.dh2k);
                keyAgreement.Add(ZRTPKeyAgreement.ec38);
                keyAgreement.Add(ZRTPKeyAgreement.ec25);

                var sasEncoding = new List<ZRTPSASEncoding>();
                sasEncoding.Add(ZRTPSASEncoding.sasb256);
                sasEncoding.Add(ZRTPSASEncoding.sasb32);

                regCfg.SIP.ZRTP = ctx.AccountProvider.CreateZRTPConfiguration();
                regCfg.SIP.ZRTP.EnableZRTP = ZRTP;
                regCfg.SIP.ZRTP.Hash = hash;
                regCfg.SIP.ZRTP.Cipher = cipher;
                regCfg.SIP.ZRTP.KeyAgreement = keyAgreement;
                regCfg.SIP.ZRTP.SasEncoding = sasEncoding;
                regCfg.SIP.ZRTP.Auth = auth;
                regCfg.SIP.ZRTP.CacheExpiry = -1;
			}

            if (RTCPFeedback)
            {
				regCfg.SIP.RTCPFeedback = RTCPFeedbackType.Compatibility;  // Include AVP and AVPF video media profiles in the SDP for backward compatibility
			}
            else
            {
				regCfg.SIP.RTCPFeedback = RTCPFeedbackType.Off; // Include only AVP video media profile in the SDP
			}

            if (Stun)
            {
				regCfg.SIP.Stun = ctx.AccountProvider.CreateStunConfiguration();
                regCfg.SIP.Stun.STUNEnabled = true;
                regCfg.SIP.Stun.STUNServer = "stun.zoiper.com";
                regCfg.SIP.Stun.STUNPort = 3478;
                regCfg.SIP.Stun.STUNRefresh = 30000;
			}
            regCfg.SIP.EnablePreconditions = Preconditions; // Reliable Provisional MUST be enabled
            regCfg.SIP.Transport = (TransportType)transportType;
            regCfg.SIP.Domain = server;
            regCfg.SIP.EnableVideoFMTP = FMTP;
            regCfg.SIP.EnablePrivacy = Privacy;
            // This is for TLS
            // Note it has to be enabled both sides
            // if you get error "415 Unsupported Media Type"
            // or "Can't find matching codec in SDP (code: 2)"
            // Make sure "EnableSRTP = true" and 
            // "SRTP key negociation = SDES" in Zoiper5
            // On succes and secure connection you will get the 
            // "OnCallSecurityLevelChanged channel: Audio level: SdesSrtp"
            // event
            regCfg.SIP.EnableSRTP = SRTP;
		}
        else if ("IAX" == protocol)
        {
			ctx.AddProtocol(ProtocolType.IAX, 4569);
            regCfg.Type = ProtocolType.IAX;
            regCfg.IAX = ctx.AccountProvider.CreateIAXConfiguration();
            regCfg.IAX.Host = server;
		}
        List<AudioVideoCodecs> codecs = new List<AudioVideoCodecs>();
        codecs.Add(AudioVideoCodecs.OPUS_WIDE);
        codecs.Add(AudioVideoCodecs.PCMU);
        // This is for the videocall
        codecs.Add(AudioVideoCodecs.vp8);

        account.MediaCodecs = codecs;

        AccountEventsHandler AccEventHandler = new AccountEventsHandler();
        AccEventHandler.OnAccountStatusChanged += Zoiper_OnAccountStatusChanged;
        AccEventHandler.OnAccountExtendedError += Zoiper_OnAccountExtendedError;
        AccEventHandler.OnAccountRetryingRegistration += Zoiper_OnAccountRetryingRegistration;
        AccEventHandler.OnAccountChatMessageReceived += Zoiper_OnAccountChatMessageReceived;
        AccEventHandler.OnAccountIncomingCall += Zoiper_OnAccountIncomingCall;
        AccEventHandler.OnAccountPushTokenReceived += Zoiper_OnAccountPushTokenReceived;

        account.SetStatusEventListener(AccEventHandler);

        account.Configuration = regCfg;

        if (ResultCode.Ok == account.CreateUser().Code)
        UserId = account.AccountID;

        if (UserId != InvalidHandle)
        {
        	ActiveUsers[UserId] = new VoIPUser
            {
            	Manager = this,
                Acc = account,
                UserName = username,
                UserId = UserId,
                EnableSRTP = SRTP
			};
            return true;
		}
        return false;
}

When the account is created, you can register it with the following function:

public bool RegisterUser()
{
	var result = Acc.RegisterAccount();
    return result.Code == ResultCode.Ok;
}

Changing the project configuration

Transport type

regCfg.SIP.Transport = (TransportType)transportType;

Possible values:

  • NA

  • UDP

  • TCP

  • TLS

STUN

if (Stun)
	{
    	regCfg.SIP.Stun = ctx.AccountProvider.CreateStunConfiguration();
        regCfg.SIP.Stun.STUNEnabled = true;
        regCfg.SIP.Stun.STUNServer = "stun.zoiper.com";
        regCfg.SIP.Stun.STUNPort = 3478;
        regCfg.SIP.Stun.STUNRefresh = 30000;
	}

Changing the used codecs

List<AudioVideoCodecs> codecs = new List<AudioVideoCodecs>();
codecs.Add(AudioVideoCodecs.OPUS_WIDE);
codecs.Add(AudioVideoCodecs.PCMU);
// This is for the videocall
codecs.Add(AudioVideoCodecs.vp8);

account.MediaCodecs = codecs;

Possible values:

  • NA

  • G729

  • GSM

  • iLBC_20

  • iLBC_30

  • h264

  • vp8

  • h264_hwd

  • SPEEX_NARROW

  • SPEEX_WIDE

  • SPEEX_ULTRA

  • G726

  • OPUS_NARROW

  • OPUS_WIDE

  • OPUS_SUPER

  • OPUS_FULL

  • AMR

  • AMR_WB

  • PCMU

  • PCMA

  • G722

Create your Windows VoIP App

Creating Zoiper SDK 2.0 Context in your application

To be able to use Zoiper SDK 2.0 in your application, you will have to add a reference to it in your project. Afterwards, you should create a context of the SDK and then to initialize it.

private void CreateContext()
{
	ctx = new Context();

	ContextEventsHandler cthEvH = new ContextEventsHandler();
    cthEvH.OnContextActivationCompleted += ZDK_NET_OnContextActivationCompleted;
    cthEvH.OnContextSecureCertError += ZDK_NET_OnContextSecureCertError;
    ctx.SetStatusListener(cthEvH);
}

The actual start of the context is usually performed after receiving the callback for successful activation.

private void ZDK_NET_OnContextActivationCompleted(ZDK_NET.Context context, ZDK_NET.ActivationResult secureCert)
{
            if (OnZoiperEvent != null)
                OnZoiperEvent("OnActivationCompleted Build: " + secureCert.Build + " Reason:" + secureCert.Reason);

            if (secureCert.Status == ActivationStatus.Success)
            {
                ctx.Configuration.SIPPort = 44444;
                ctx.Configuration.RTPPort = 55555;

                ctx.StartContext();

                //Account account;
                //Call activeCall;
                

                ctx.VideoControls.SetFormat(352, 288, 6);
                //OnActivationSuccess(secureCert.Reason);
            }
            else
            {
                OnActivationError(secureCert.Reason);
            }
        }

Zoiper SDK 2.0 initialization function example

The following example is from the Demo app. It illustrates how to include the combined initialization of Online and Offline activation

public bool Initialize(String path ,String certUserName, String certPassword)
{
	if (ctx == null)
    {
    	CreateContext();
	}

    string LogFile = Path.GetDirectoryName(Assembly.GetEntryAssembly().Location) + "\\zdk.net.log.txt";
    ctx.Logger.LogOpen(LogFile, null, LoggingLevel.Debug, 0);

    if (path != "" && countInits == 0)
    {
    	ctx.Activation.CreateOfflineActivationFileSDK(path, certUserName, certPassword);
        countInits++;
        return true;
	}
    else if (1 == countInits)
    {
    	ctx.Activation.StartSDK(path + "\\certificate", certUserName, certPassword);
        countInits--;
        return true;
	}
    else
    {
    	ctx.Activation.StartSDK("", certUserName, certPassword);
	}

    return true;
}

.Net Framework SDK Reference

You can find the API and method references here.