Table 2.

Performance metrics for evaluating DQL in SDN.

Metric	Description	Significance	Example findings/references
Throughput	Total data successfully delivered over time	Reflects link utilization and efficiency	DQL improved throughput by 18–22% vs. ECMP (Fu et al., 2020)
Packet Loss Rate	% of packets dropped due to congestion or link failure	Indicates network reliability	Loss reduced by ~15% under mixed workloads (Zhang et al., 2023)
Avg. End-to-End Delay	Time for a packet to travel from source to destination	Critical for real-time and QoS-sensitive apps	Temporal DQL cut delay by ~12% (Sharma et al., 2024)
Convergence Time	Time required for DQL to learn a stable routing policy	Demonstrates learning efficiency	DRL-R converged 30% faster than Q-learning (Liu et al., 2021)