A system for assisting in controlling real-time transport protocol flow through multiple networks via screening is disclosed. The system utilizes a transceiver, a memory having logic stored therein defining functions to be performed by the system, and a processor. The processor is configured by the memory to perform the functions of: determining if route information received by the transceiver is from an external source or an internal source; if the route information is from an external source, performing a first internal screen of the route information, wherein a destination address defined by the received route information is compared to a local destination address defined by the first internal screen; and if the route information is from an internal source, performing a second internal screen of the route information, wherein an origin address defined by the received route information is compared to a local origin address defined by the second internal screen.