How to: Fork an IM invite to multiple targets

Learn how to use a script application to fork a message in a Microsoft Lync Server 2013 deployment.

Applies to: Lync 2013 | Lync Server 2013

When you forward a message to multiple endpoints, forking occurs. Ringing multiple devices that belong to a user simultaneously is an example of forking. The process of broadcasting a message is used to fork a message to multiple users. The Microsoft Lync Server 2013 SIP Application API supports this kind of scenario by using either script-only or managed code applications, depending on the complexity of the application logic. In this topic, a script-only application is used to fork a message in a Lync Server 2013 deployment.

The following Microsoft SIP Processing Language (MSPL) script forks an INVITE request to all currently active endpoints that are connected to the targeted user.

<?xml version="1.0"?>
<r:applicationManifest
   r:appUri="http://www.contoso.com/ForkInvite"
   xmlns:r="http://schemas.microsoft.com/lcs/2006/05">
   <r:allowRegistrationBeforeUserServices/>
   <r:serverFilter roles="ALL"/>

   <!-- handle INVITE requests -->
   <r:requestFilter methodNames="INVITE"
                 strictRoute="false"
                 registrarGenerated="true"
                 domainSupported="true"/>

   <!-- handle no response. -->
   <r:responseFilter reasonCodes="NONE"/>

   <r:proxyByDefault action=”true”/>

   <!-- Script-only application. -->
   <r:scriptOnly/>

   <r:splScript><![CDATA[
     if (!sipRequest) {
       return;
     }

     foreach( h in GetHeaderValues(StandardHeader.UserAgent)) {
       if (ContainsString(h, "Microsoft Lync", false)) {
         Log("Event", false, "With Lync, forking is not necessary.");
 return;
       }
     }
     
     forked=false;
     toUri = GetUri(sipRequest.To); 
     toUserAtHost = GetUserAtHost(toUri);
     Log("Event", true, "Enter ForkInvite...", "\r\ntoUri: ", toUri, "\r\ntoUserAtHost: ", toUserAtHost);
     BeginFork(false, 0);
     foreach(dbEndpoint in QueryEndpoints(toUserAtHost)) {
       Log("Event", false, "dbEndpoint: ", dbEndpoint.ContactInfo);
       Fork(dbEndpoint.ContactInfo);
       forked=true;
     }
     EndFork();

     if (!forked) {
       Log("Event", false, "Invite not forked");
       ProxyRequest("");
     }
     else {
       Log("Event", false, "Invite forked");
     }
   ]]></r:splScript>
</r:applicationManifest>

Fixed routing resembles message forwarding. It must be disabled in the application manifest. This means that the strictRoute attribute of the requestFilter element must be set to false in the application manifest for message forking. Also, forking should not be applied to a session-bound message.

See also

Concepts

Learn the basics of Lync Server 2013 SDK

How to use Lync Server 2013 SDK

Lync Server 2013 SDK general reference

Scenarios for using the Lync Server 2013 API