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Direct Connect Bandwidth Calculator

Size Direct Connect ports with 50% redundancy headroom and price port hours plus data transfer out.

About Direct Connect Bandwidth Calculator

AWS resiliency guidance for Direct Connect is to provision so that peak traffic still fits after a failure, which for a two-port design means running each port at no more than 50% utilisation. Doubling the requirement and dividing by the port speed gives the port count, and the bill combines port hours — charged whether or not traffic flows — with a per-GB data transfer out rate that is materially cheaper than internet egress. A Direct Connect port takes weeks to provision through a partner, so discovering the second port is missing during an outage is not a problem you can fix on the day.

Formula

Direct Connect Bandwidth

provisioned = port speed × ports; resilient capacity = provisioned × 50%; ports needed = max(2, ceil(required × 2 ÷ port speed)).

port speed
Dedicated or hosted connection speed
50%
Headroom that keeps peak load servable after losing half the ports
required
Peak bandwidth the hybrid path must carry

Worked example

With the default values below, Direct Connect Bandwidth Calculator returns Resilient Capacity of 10,000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Peak bandwidth requiredminimum 1 Mbps
6,000 Mbps
Port speedone of 50 Mbps — hosted connection, 100 Mbps — hosted connection, 500 Mbps — hosted connection, 1 Gbps, 2 Gbps, 5 Gbps, 10 Gbps, 25 Gbps, 100 Gbps
10 Gbps
Ports provisionedaccepts 1–8 ports
2 ports
Price per port-houraccepts 0–100 USD
2.25 USD
Data transfer out per monthminimum 0 GB
20,000 GB
Data transfer out price per GBaccepts 0–2 USD
0.02 USD
Billable hours per monthaccepts 1–744 hours
730 hours

Results

Resilient Capacity
10,000 Mbps
Provisioned Capacity
20,000 Mbps
Utilisation of Provisioned Capacity
30.0%
Ports Needed with 50% Headroom
2
Estimated Monthly Cost
$3,685.00
Resiliency Check
Survives the loss of half the provisioned ports

Step by step

  1. 1Values used
  2. 2Direct Connect Bandwidth
  3. 3Resilient Capacity= 10,000 Mbps
  4. 4Provisioned Capacity= 20,000 Mbps
  5. 5Utilisation of Provisioned Capacity= 30.0
  6. 6Ports Needed with 50% Headroom= 2
  7. 7Estimated Monthly Cost= 3,685.00
  8. 8Resiliency Check= Survives the loss of half the provisioned ports

Assumptions and limits

  • The result is derived only from the 7 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Direct Connect Bandwidth calculated?

provisioned = port speed × ports; resilient capacity = provisioned × 50%; ports needed = max(2, ceil(required × 2 ÷ port speed)). AWS resiliency guidance for Direct Connect is to provision so that peak traffic still fits after a failure, which for a two-port design means running each port at no more than 50% utilisation. Doubling the requirement and dividing by the port speed gives the port count, and the bill combines port hours — charged whether or not traffic flows — with a per-GB data transfer out rate that is materially cheaper than internet egress.

Why does Direct Connect Bandwidth matter?

A Direct Connect port takes weeks to provision through a partner, so discovering the second port is missing during an outage is not a problem you can fix on the day.

What values do I need to enter?

This calculator takes 7 inputs: Peak bandwidth required, Port speed, Ports provisioned, Price per port-hour, Data transfer out per month, Data transfer out price per GB, Billable hours per month. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

Why plan for 50% utilisation instead of 80%?

Because the surviving port has to absorb the failed port's traffic. At 80% per port a single failure leaves you 60% oversubscribed and every application feels it; at 50% the failover is invisible. AWS's maximum resiliency model goes further with separate devices and locations.

Should I keep a VPN as backup?

Yes for most designs. A Site-to-Site VPN over the internet is inexpensive standby capacity, though at about 1.25 Gbps per tunnel it will not match a 10 Gbps port, so size expectations for degraded rather than equal service.

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