SOAP routing is essential to a service network. That is, a service engine should be able to drop a SOAP message on the grid and it should magically get to its destination. If a destination IP address is specified, why wouldn't it reach its destination? One reason is that the IP address is, "non-reachable". This is to say that something prevents the direct addressing of a given node on a network. Typically, this is the result of a firewall, proxy or NAT. In some cases, large internal networks may have been broken down into smaller domains to make them more managable or to control traffic. In other cases, devices like firewalls or present to secure networks. Either way, the problem of non-reachable nodes surfaces.
This is where a domain-based SOAP router enters the picture. The SOAP router takes on the responsibility of finding non-reachable nodes - enabling a SOAP message to reach its final destination even when the sender didn't know the actual address. In virtually every business to business web service interaction, we can expect that the participants will NOT know the physical address of where the other guys services are located. And why should they? A company should be able to move its servers around and not worry about having to update the trading partners on the new URI's or IP addresses. A cross-domain SOAP router enables a corporation to maintain an internal routing map for services, thus abstracting the 'service consumers' from the physical network.