Network Capacity Planner

🌐 Network Capacity Planner – Estimate, Analyze, and Plan Bandwidth

The Network Capacity Planner helps network engineers, IT architects, and system administrators quantify how much usable bandwidth a network segment can deliver — and how long that capacity will last as traffic grows. By combining link aggregation, protocol overhead, redundancy modes, and compound annual growth projections, it turns raw link-speed figures into actionable capacity decisions.

🔢 Core Capacity Formulas

Every result flows through a three-stage pipeline. Start with the raw total capacity — simply the number of active links multiplied by the per-link speed:

Raw Capacity = Active Links × Link Speed

Next, subtract protocol overhead — the bytes consumed by Ethernet frames, TCP/IP headers, and any encapsulation layers (MPLS, IPsec, GRE, VXLAN):

Effective Capacity = Raw Capacity × (1 − Overhead% / 100)

Finally, apply a utilization target to leave headroom for traffic bursts and avoid congestion:

Usable Capacity = Effective Capacity × (Utilization Target% / 100)

🔗 Redundancy Modes Explained

The redundancy mode determines how many physical links contribute to throughput. Choosing the wrong model leads to over-estimated capacity — a common cause of unexpected congestion after a failover event.

📈 Traffic Growth Projection (CAGR)

Enterprise traffic typically grows 20–40% per year, driven by video conferencing, cloud workloads, and IoT device proliferation. The planner uses the compound annual growth rate (CAGR) formula to project demand year by year:

Projected Traffic (year n) = Current Peak × (1 + Growth Rate / 100)^n

When projected traffic exceeds usable capacity, the tool highlights the capacity exhaustion year and calculates exactly how much additional bandwidth you need to order before that deadline.

⚡ Protocol Overhead Quick Reference

🎯 Utilization Target Best Practices

A common mistake is provisioning links at 100% of their rated speed. Under bursty traffic — video streams, large file transfers, backup windows — momentary utilization spikes cause queue buildup and packet drops that degrade application performance well before the link is saturated on average.

Industry-recommended utilization targets by link type:

• Enterprise LAN uplinks: 70–80% — balances cost and burst headroom.
• WAN and internet circuits: 60–70% — higher latency sensitivity.
• Data centre interconnect (DCI): 50–65% — strict SLA environments.
• ISP peering/transit: 40–60% — traffic engineering margins.

🏢 Primary Use Cases

This tool is designed for planning scenarios including:

• Data centre interconnect (DCI) — sizing 10/40/100 GbE links between sites with redundancy and growth margins.
• Campus and enterprise WAN — aggregating branch uplinks and verifying that MPLS or SD-WAN circuits can sustain peak loads.
• Hybrid-cloud uplink sizing — calculating how many dedicated connections or VPN tunnels are needed for cloud-bound traffic.
• Disaster-recovery link planning — confirming standby circuits can carry full production load after a failover event.
• Network refresh and upgrade budgeting — producing quantified capacity gap reports to justify hardware procurement requests.

📊 Understanding the Output Metrics

The planner produces a complete capacity pipeline: raw → effective → usable → headroom. Each stage shows a concrete bandwidth figure so you can trace exactly where capacity is being consumed. The per-link utilization metric shows what fraction of each individual link's rated speed is being used — useful for identifying whether LACP hashing is distributing traffic evenly. The SLA coverage check verifies that committed information rates (CIR) are protected even after derating for overhead and utilization targets.

Results are auto-scaled into the most readable unit (bps, Kbps, Mbps, Gbps, or Tbps) so you always see 26.6 Gbps rather than 26,600 Mbps.