Intent-based networking (IBN) derives configuration from operator-stated goals, and its first step β translating a natural-language intent into enforceable service-level objectives (SLOs) grounded in a live snapshot of network state β is increasingly handed to large language models (LLMs). Those models add cost and energy to the management loop and typically need multi-GPU cloud hosting. This paper asks whether lightweight open models can take over that step dependably.
The authors evaluate ten LLMs under 10 billion parameters from five families, across four prompting setups, on 716 placement intents, scoring translation quality, intent validation, hallucination, energy and robustness to phrasing. The best configurations reach a strict F1 of 0.943 and reject up to 191 of 195 invalid intents. With few-shot reasoning the strongest models invent unsupported quality-of-service (QoS) requirements in about one response in a hundred, while zero-shot setups struggle. A translated intent costs 0.044 to 0.148 Wh of graphics processing unit (GPU) energy without reasoning, and the extra energy spent on reasoning pays off mainly for the weaker models.