This sample shows up to use Direct Binding in Biztalk Server 2004 to send messages from one Orchestration to another using Partner Ports. Direct binding is easily misunderstood and Partner Port binding can be rather confusing to set up. Direct binding still uses the publish and subscribe system in Biztalk to send messages between Orchestrations.
This sample should work with BizTalk 2004 and BizTalk 2006.
Get more information from the original blog post on this topic: https://www.biztalkgurus.com/biztalk_server/biztalk_blogs/b/biztalk/archive/2005/08/10/direct-binding-sample-for-biztalk-2004.aspx