using Microsoft.Rtc.Signaling;

internal SipPeerToPeerEndpoint m_SipPeerToPeerEndpoint;
RealTimeServerConnectionManager m_RealTimeServerConnectionManager;

m_RealTimeServerConnectionManager = new RealTimeServerTcpConnectionManager();

m_SipPeerToPeerEndpoint = new SipPeerToPeerEndpoint(textBoxSipUri.Text,
  m_RealTimeServerConnectionManager,
  SipTransportType.Tcp,
  textBoxDomainName.Text,
  5060);

Form2 notificationForm = new Form2(this);
notificationForm.Show();

private NotificationOperation m_Broadcast;
private Form1 m_ParentForm;

Form1 Parent

m_ParentForm = Parent;

m_Broadcast = new NotificationOperation(textBoxMessage.Text, textBoxDestination.Text, m_ParentForm.m_SipPeerToPeerEndpoint, backgroundWorker1);

using Microsoft.Rtc.Signaling;
using System.ComponentModel;
using System.Net;
using System.Net.Mime;

public class NotificationOperation : IOfferAnswer
{
}

private String m_Notification;
private String m_Destination;
private SipPeerToPeerEndpoint m_Endpoint;
private BackgroundWorker m_Worker;

public NotificationOperation(String Notification, String Destination, SipPeerToPeerEndpoint endpoint, BackgroundWorker Worker)
{
  m_Notification = Notification;
  m_Destination = Destination;

  if (endpoint != null)
  {
	m_Endpoint = endpoint;
  }
  else
  {
	throw new InvalidOperationException("Cannot pass a null endpoint to the Notification Operation");
  }

  //Set the destination address. 
  Target To = new Target();
  To.SipUri = m_Destination;

  m_Worker = Worker;
  SignalingSession Session = new SignalingSession(m_Endpoint, new RealTimeAddress(To.SipUri));
  Session.LocalParticipant.ApplicationContext = To;
  Session.OfferAnswerNegotiation = this;
  Session.BeginParticipate(ParticipateCallback, Session);
}

//Callback for the BeginParticipate method.
private void ParticipateCallback(IAsyncResult ar)
{
  SignalingSession Session = ar.AsyncState as SignalingSession;
  Target To = Session.LocalParticipant.ApplicationContext as Target;
  SipMessageData Response = null;

  try
  {
	Response = Session.EndParticipate(ar);
  }
  catch (OperationTimeoutException e)
  {
	string msg = e.ToString();
  }
  catch (FailureResponseException e)
  {
	string msg = e.ToString();
  }
  catch (ConnectionFailureException e)
  {
	string msg = e.ToString();
  }
  catch (RealTimeException e)
  {
	string msg = e.ToString();
  }
  finally
  {
	if (Response != null)
	{
	Session.BeginSendMessage(MessageType.Message, new ContentType("text/plain"), Encoding.UTF8.GetBytes(m_Notification), SendMessageCallback, Session);
}
  }
}

//Callback for the BeginSendMessage method.
private void SendMessageCallback(IAsyncResult ar)
{
  SignalingSession Session = ar.AsyncState as SignalingSession;
  SipResponseData Response = null;
  Target To = (Target)Session.LocalParticipant.ApplicationContext;

  try
  {
	Response = Session.EndSendMessage(ar);
  }
  catch (FailureResponseException e)
  {
	string msg = e.ToString();
  }
  catch (OperationTimeoutException e)
  {
	string msg = e.ToString();
  }
  catch (RealTimeException e)
  {
	string msg = e.ToString();
  }
  finally
  {
	Session.BeginTerminate(TerminateCallback, Session);
  }
}

Callback for the BeginTerminate method.
private void TerminateCallback(IAsyncResult ar)
{
  SignalingSession Session = ar.AsyncState as SignalingSession;
  Session.EndTerminate(ar);
}

public ContentDescription GetOffer(object sender)
{
  SignalingSession Session = sender as SignalingSession;
  IPAddress IpAddress;

  // This method is called back every time an outbound INVITE is sent.
  if (Session.Connection != null)
  {
	IpAddress = Session.Connection.LocalEndpoint.Address;
  }

  else
  {
	IpAddress = IPAddress.Any;
  }

  Sdp<SdpGlobalDescription, SdpMediaDescription> SessionDescription = new Sdp<SdpGlobalDescription, SdpMediaDescription>();

  //Set the origin line of the SDP
  //s, t, and v lines are automatically constructed
  SessionDescription.GlobalDescription.Origin.Version = 0;
  SessionDescription.GlobalDescription.Origin.SessionId = "0";
  SessionDescription.GlobalDescription.Origin.UserName = "-";
  SessionDescription.GlobalDescription.Origin.Connection.Set(IpAddress.ToString());

  //Set the connection line
  SessionDescription.GlobalDescription.Connection.TrySet(IpAddress.ToString());

  SdpMediaDescription mditem = new SdpMediaDescription("message");

  mditem.Port = 5060;
  mditem.TransportProtocol = "sip";
  mditem.Formats = "null";

  SdpAttribute aitem = new SdpAttribute("accept-types", "text/plain");

  mditem.Attributes.Add(aitem);

  //Append the Media description to the Global description
  SessionDescription.MediaDescriptions.Add(mditem);

  ContentType ct = new ContentType("application/sdp");

  return new ContentDescription(ct, SessionDescription.GetBytes());

}

//Required interface member.
public ContentDescription GetAnswer(object sender, ContentDescription offer)
{
  return null;
}

//Required interface member.
public void SetAnswer(object sender, ContentDescription answer)
{
  return;
}

//Required interface member.
public void HandleOfferInInviteResponse(object sender, OfferInInviteResponseEventArgs e)
{
  return;
}

//Required interface member.
public void HandleOfferInReInvite(object sender, OfferInReInviteEventArgs e)
{
  return;
}

//This class stores the SIP URI of the 
//distribution group receiving the broadcast.
public class Target
{
  string m_SipUri;
  public string SipUri
  {
	get
	{
	return m_SipUri;
}

	set
	{
	SipUriParser TargetUri;

	if (SipUriParser.TryParse(value, out TargetUri))
	{
		m_SipUri = value;
}

	else
	{
		throw new InvalidOperationException("Cannot assign the current value");
}

}
  }
}