How to send out of dialog SIP messages

This article is a detailed guide about sending out of dialog SIP messages in relation with Ozeki VoIP SIP SDK. After reading through this page you will be fully familiar with all the essential terms concerning out of dialog SIP messages and what you will need for creating your own solution using Ozeki VoIP SIP SDK.

Introduction

SIP (session initiation protocol) messages are basically used for phone line establishment by a PBX between two VoIP clients. This can be made by the provided calls of Ozeki VoIP SIP SDK. These calls mask the actual SIP message sending and make all the background operations that are needed for line establishment.

Figure 1 - Out of dialog SIP message

In some cases there is need for sending SIP messages that are not in connection with the actual phone call but contain some notification or state information that can affect the call too.

The following program code uses the background support of Ozeki VoIP SIP SDK, therefore you will need to download and install the SDK on your computer before starting to use the program code. You will also need to have Visual Studio 2010 or compatible IDE and .NET Framework installed on your system, as the program code below is written in C# language.

When using Ozeki VoIP SIP SDK you can send out of dialog SIP messages on a phone line object by calling the SendOutofDialogInstantMessage method defined in the IPhoneLine interface (Code 1).

void SendOutofDialogInstantMessage(string recipient, string content);

Code 1 - The method definition for sending out of dialog SIP messages

The recipient of the message can be the phone number (according to the SIP account settings) of the remote party or a complete SIP uri like "875@192.168.115.10".

If you want to be notified about an out of dialog SIP message, you need to subscribe for the OutofDialogInstantMessageReceived event (Code 2).

phoneLine.OutofDialogInstantMessageReceived +=new EventHandler<VoIPEventArgs<MessageDataPackage>>(phoneLine_OutofDialogInstantMessageReceived);

Code 2 - Subscribing the phone line for the event of receiving out of dialog SIP message

The actual behavior that is needed when an out of dialog SIP message is received needs to be implemented in the phoneLine_OutofDialogInstantMessageReceived event handler method. In this method you can define what should the program do in case of a certain out of dialog message.

This article introduced you the basic knowledge about sending out of dialog SIP messages and showed how Ozeki VoIP SIP SDK can help you to fulfill your wishes about this topic. If you have read through this page carefully, you already have all the knowledge you need to start on your own solution.

As you are now familiar with all the terms concerning this topic, now it is time to take a step further and explore what other extraordinary solution Ozeki VoIP SIP SDK can provide to you.

If you have any questions or need assistance, please contact us at info@voip-sip-sdk.com

You can select a suitable Ozeki VoIP SIP SDK license for your project on Pricing and licensing information page

Related Pages

• Setup Ozeki VoIP SIP SDK efficiently: Quick start guide
• Download Ozeki VoIP SIP SDK form the Ozeki VoIP SIP SDK download page
• You can find licensing information of Ozeki VoIP SIP SDK on Pricing and licensing information page