The key advantage of clearinghouse operations is that a single technical infrastructure can be used to provide all four operations services to members—from simple bilateral exchange to global enhanced services. To understand the simplicity of the clearinghouse architecture, first consider the basic components of VoIP services. As outlined in Figure 1, VoIP operations consists of a management layer (an application server or intelligent network [IN] layer), a signaling proxy to exchange call setup data between networks, and a transport layer (IP gateways and IP network). Using this simple model, carriers worldwide have offered calling-card, single-stage dialing, and wholesale services for more than two years.

Figure 1. Basic VoIP Network

A clearinghouse, in its basic technical configuration, is simply an application and a signaling protocol (such as H.323) without gateways. It provides routing instructions, service logic, and billing capabilities to other networks. As such, adding clearinghouse capabilities requires the provisioning of the IN layer and database to the network to provide the same routing and service management to other networks that the existing network control layer provides for its gateways. Figure 2 is a diagram of basic clearinghouse operations.

Figure 2. Clearinghouse Call Flow

The technical and business requirements for becoming a VoIP clearinghouse are extremely simple. Service providers with existing international or regional business can leverage existing infrastructure to drive new revenues to their networks with minimal investment:

• clearinghouse applications
• bandwidth provisioning and IP access
• sales and marketing channel for recruiting partners and members
• financial and network management infrastructure

With these simple tools in place, an operator has everything it needs to enter the profitable market for IP clearinghouse services.