This paper provides a comprehensive overview of the uD3TN project's development, detailing its transformation into a flexible and modular software implementation of the Delay-/Disruption-Tolerant Networking (DTN) Bundle Protocol. Originating from uPCN, designed for microcontrollers, uD3TN has undergone significant architectural refinement to increase flexibility, compatibility, and performance across various DTN applications. Key developments include achieving platform independence, supporting multiple Bundle Protocol versions concurrently, introducing abstract Convergence Layer Adapter (CLA) interfaces, and developing the so called Application Agent Protocol (AAP) for interaction with the application layer. Additional enhancements, informed by field tests, include Bundle-in-Bundle Encapsulation and exploring a port to the Rust programming language, indicating the project's ongoing adaptation to practical needs. The paper also introduces the Generic Bundle Forwarding Interface and AAPv2, showcasing the latest innovations in the project. Moreover, it provides a comparison of uD3TN's architecture with the Interplanetary Overlay Network (ION) protocol stack, highlighting some general architectural principles at the foundation of DTN protocol implementations.

翻译：本文全面概述了μD3TN项目的发展历程，详细阐述了其如何演变为一个灵活、模块化的延迟/中断容忍网络（DTN）捆绑协议软件实现。项目起源于为微控制器设计的μPCN，经过显著的架构精化，以提升在各种DTN应用中的灵活性、兼容性和性能。关键进展包括实现平台无关性、同时支持多个捆绑协议版本、引入抽象的汇聚层适配器（CLA）接口，以及开发用于与应用层交互的所谓应用代理协议（AAP）。基于现场测试的额外增强功能包括捆绑包内封装（Bundle-in-Bundle Encapsulation）以及探索向Rust编程语言的移植，这表明项目正在持续适应实际需求。本文还介绍了通用捆绑转发接口（Generic Bundle Forwarding Interface）和AAPv2，展示了项目的最新创新。此外，本文比较了μD3TN架构与行星际覆盖网络（ION）协议栈，突显了DTN协议实现基础中的一些通用架构原则。