Network Upgrade Time Calculator
Estimate a fleet software upgrade: image transfer, reload time, per-device duration and total elapsed campaign time.
Inputs
Total Campaign Time
4.10hours
Time per Device
16.40minutes
Image Transfer Time
2.40minutes
Batches Required
15
Service Outage per Device
14.00minutes
Step by step
Values used
Devices to upgrade = 120 devices; Software image size = 900 MB; Transfer bandwidth per device = 50 Mbps; Reload and boot time = 9 minutes; Health check per device = 5 minutes; Devices upgraded per batch = 8 devices
Network Upgrade Time
transfer minutes = image MB × 8 ÷ (Mbps × 60); per device = transfer + reload + health check; campaign = batches × per-device time.
Total Campaign Time
= 4.10 hours
Time per Device
= 16.40 minutes
Image Transfer Time
= 2.40 minutes
Batches Required
= 15
Service Outage per Device
= 14.00 minutes
How it works
Within a batch the devices are upgraded in parallel, so the campaign length is the number of batches multiplied by the time one device takes rather than the sum over all devices. Only the reload and health-check portion is customer-affecting; the image transfer happens while the device is still in service. Rollouts are planned in change windows of a few hours, and the batch arithmetic is what tells you whether a 120-device fleet is one night's work or six.
Formula
Network Upgrade Time
transfer minutes = image MB × 8 ÷ (Mbps × 60); per device = transfer + reload + health check; campaign = batches × per-device time.
- × 8
- Megabytes converted to megabits
- batches
- ceil(devices ÷ devices per batch)
Frequently Asked Questions
How is Network Upgrade Time calculated?
transfer minutes = image MB × 8 ÷ (Mbps × 60); per device = transfer + reload + health check; campaign = batches × per-device time. Within a batch the devices are upgraded in parallel, so the campaign length is the number of batches multiplied by the time one device takes rather than the sum over all devices. Only the reload and health-check portion is customer-affecting; the image transfer happens while the device is still in service.
Why does Network Upgrade Time matter?
Rollouts are planned in change windows of a few hours, and the batch arithmetic is what tells you whether a 120-device fleet is one night's work or six.
What values do I need to enter?
This calculator takes 6 inputs: Devices to upgrade, Software image size, Transfer bandwidth per device, Reload and boot time, Health check per device, Devices upgraded per batch. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
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