In this digital era of Information and communication Technologies [ICT] it has been critical to foster sustainable energy-efficient communication and networking technologies to encounter the increasing demand of information and communication technologies in various applications like healthcare, business intelligence and smart cities. Computational and network sustainability plays a critical role in communication networks and appears as an interdisciplinary area of research to design and develop a sustainable computing technologies and communication networks with an enhanced Quality of Service characteristics. This International Conference on Sustainable Communication Networks and Applications [ICSCN 2021] facilitates an innovative platform for researchers and academicians to share and exchange their research ideas to address the prodigious research challenges in developing an energy efficient communication network systems, green computing architectures and sustainable network resource management frameworks. The main objective of the conference is to report and discuss the results on state-of-the-art researches in developing a sustainable communication network architecture and applications. The main objective of ICSCN is to serve as a confluence point between researchers, academicians and industrialists to present their state-of-the-art research and works in the areas of sustainable communication networks and applications to materialize prodigious benefits in order to meet the global sustainable needs. The extensive goal of ICSCN is to promote a community-wide discussions identifying the up-to-date technologies and theories for sustainable computing and communication networks to address the emerging challenges and create a sustainable environment, green energy and network models, algorithms, platforms and tools required to facilitate the next-generation sustainable communication and networking infrastructure. The International Conference on Sustainable Communication Networks and Applications will be an intriguing platform for scientists, researchers, research scholars and industrialists to present, share and exchange their ideas on the recent advances in sustainable communication networks and applications.