The International Conference on the Design of Reliable Communication Networks (DRCN) has been held for more than 20 years to address topics related to the reliability and availability of communication networks, and has grown to become the meeting place where researchers from both industry and academia get together to advance the state-of-the-art in the field. The DRCN conference has always been a multidisciplinary forum bringing together scientists from diverse fields including engineering of survivable equipment and network technologies, network management and monitoring, and data analytics for fault diagnosis. The 21st edition of the conference will be held in Ningbo Pan Pacific Hotel, China, from May 12-15, 2025. We are pleased to invite you to contribute and participate in DRCN 2025 encouraging you to submit novel and high-quality work to the conference.