Abstract:To address the challenge that traditional parsing methods struggle to meet the real-time and interpretability requirements of modern network operation and security analysis in emerging environments such as 5G and integrated space-ground networks, which are driven by rapidly evolving network protocols, this paper studies a retrieval augmented generation system for intelligent protocol understanding. This system employs key technologies such as protocol-aware knowledge preprocessing, multimodal hybrid index construction, and protocol-aware generator fine-tuning. Experimental evaluation on a test set covering 12 mainstream protocols and nearly 2000 questions demonstrates a soft recall rate of 77.97%, significantly outperforming mainstream methods such as Modular RAG and GraphRAG. Furthermore, the end-to-end accuracy for hexadecimal reasoning questions improved from 58.24% to 79.63%, while performance remained stable for other question types. Practical application verification confirms that this technology meets the requirements of high-precision, traceable, and external-requirement-free protocol understanding in engineering scenarios such as intelligent protocol analysis and self-explaining networks, providing an effective technical path for related fields.