From Ethernet to Wi-Fi: Flow Feature Selection and Construction for Traffic Classification

We evaluate Jev on ten dataset-defined application labels in CESNET-QUICEXT-25 using only the first ten packets' sizes, directions, and inter-packet times. To the best of our knowledge, this is the first empirical study of general-purpose decision models, represented here by Jev, for application classification of network flows. Across 52,000 records from 26 collection weeks following the training period, 40 fixed labeled examples raise Jev's accuracy from 9.80% to 28.42%. Random Forest and Extra Trees trained on 8,000 records achieve 69.95% and 66.80% and outperform Jev in every week. Increasing Jev's context to 150 examples yields 34.50% on the first test week. On a paired 100-record subset, Jev with 40 examples achieves 29% accuracy at a median request time of 0.750 s, versus 37% and 6.036 s for the generative language model OpenAI GPT-5.6 Sol with high reasoning effort through Azure; Jev also incurs lower API charges. The paired subset does not establish an accuracy advantage for either service, and the timing reflects different service configurations. Thus, labeled examples substantially improve Jev, but the tested Jev configurations remain less accurate than trained tree ensembles; unequal supervision budgets and fixed configurations prevent attributing the gap to a single cause.

Network traffic analysis in cloud and internet service provider (ISP) networks increasingly relies on machine learning (ML) models, as encryption and service consolidation make rule-based classification unreliable. At high flow-arrival rates, however, new flows can arrive faster than end-to-end analysis pipelines can process. Unlike typical cloud inference workloads, packets from the same flow arrive over time and require per-flow state. This streaming, stateful setting limits naive scale-out with stateless workers. This paper presents FlowWise, a serving system for streaming, stateful flow intelligence on commodity CPU/GPU servers that jointly selects (i) how many packets to collect and (ii) which model(s) to apply for each flow to balance latency, service rate, and accuracy. Across three representative tasks, inference time across candidate models differs by 1.8x-141.3x, while packet waiting time can exceed feature computation and inference by 6-8 orders of magnitude at the tail. FlowWise exploits these gaps with an uncertainty-driven fast-slow cascade: it issues early predictions from a one-packet model and escalates only uncertain flows to slower models that wait for additional packets and use richer features. A queue-centric runtime maintains per-flow state, performs asynchronous feature joining, and uses brokered, flow-ID-keyed streams to distribute workload across heterogeneous workers. FlowWise serves 76.3% of flows within 16 ms, improving median end-to-end serving latency by 40.5x while increasing service rate and maintaining similar accuracy to always running the slow model. With thousands of packet-header features per flow, our scale-up benchmark sustains over 48.5k new flows per second on a single 16-core commodity CPU server, comparable to reported flow-arrival rates in city-backbone traces. FlowWise is open sourced at https://github.com/noise-lab/FlowWise.

Deep learning has achieved strong performance in encrypted traffic classification (ETC), yet its computational cost limits deployment on resource-constrained network devices such as routers and middleboxes. Existing compression methods mainly operate on weights, channels, hidden representations, or predictions, but do not explicitly determine which protocol fields and structural contexts should remain. We propose Pruned Traffic Trees (PTT), a three-level protocol-structured model family that treats native protocol structures as compression units. PTT-Full learns protocol-structured representations and field salience from complete Protocol Tree Graphs (PTGs), with flow-level self-supervised learning and protocol-presence-aware sparse execution. The learned salience and TopK+$k$ closure construct Distilled PTGs (PTG-Ds) for PTT-Distilled, while PTT-Lite inherits this topology and reduces width through structure-aligned transfer and flow-level logits distillation. Under flow-disjoint and Strong Information Information (SII)-masked settings, PTT-Full achieves Macro-F1 scores of 0.9519 and 0.9416 on CSTNET-TLS1.3 and CipherSpectrum, while PTT-Lite retains 0.9325 and 0.9136 with 80.3% and 61.3% fewer parameters, 98.85% and 98.78% lower effective GFLOPs, and 8.75$\times$ and 8.46$\times$ CPU inference speedups. These results demonstrate that treating protocol structure itself as the compression object enables effective performance-efficiency trade-offs for lightweight ETC.