Since distributed real-time systems require strict time constraints on communication, packets must be routed to meet the real-time constraints. To reduce the communication latency and satisfy the real-time constraints, a minimal path for each pair of source and destination is selected, then its schedulability is verified if the selected path meets the constraints. Since such routing schemes may form cyclic dependencies across multiple packets, routing schemes must be designed to guarantee deadlock-freedom. In this paper, we propose routing schemes of a real-time communication link that guarantee both real-time capability and deadlock-freedom for distributed real-time systems. Simulation results show that the proposed routing schemes improve the schedulability of communications by up to 30%.