Sizing TCP windows, Mathis throughput bounds under loss, packet rates, and file-transfer times — for the link you actually have.
Subnet / CIDR Calculator · Subnet Quiz · Availability / SLA Calculator · Data-Center Capacity Planner · Tick-to-Trade Latency Calculator · Optical Link Budget Calculator · PTP Timing Budget Calculator · ECMP Hash Polarization Visualizer · Firewall ACL Rule Analyzer · Network config verifier · PTP/SyncE Network-Wide Timing Simulator · Wireshark Display Filter Builder · Wi-Fi Channel Interference Planner · QoS Token-Bucket Policer & Shaper Simulator — all free, all run entirely in your browser.