1. A computer-implemented method, comprising: aggregating routing awareness for multiple autonomous networks, the routing awareness specifying whether individual networks of the multiple autonomous networks support a routing awareness protocol for propagating routing awareness for routing of a communication session, the routing awareness protocol identified via a custom protocol identifier (ID) and indicating one or more procedures for propagating attributes of the individual network and the communication session; and propagating the routing awareness to one or more of the multiple autonomous networks independently of a data stream of the communication session.