Size the SD-WAN circuit for a branch from user count, concurrency, growth and overlay overhead.
The busy-hour rate is applied only to concurrent users, then inflated for growth over the contract term and for tunnel encapsulation. Rounding up to a carrier tier turns the figure into something you can actually order. Branch circuits are contracted for two or three years, so a 20% sizing error is either a permanent overspend or a permanent congestion ticket queue.
SD-WAN Link
required = users × concurrency × per-user rate × (1 + growth) × (1 + overlay overhead), rounded up to the next carrier tier.
required = users × concurrency × per-user rate × (1 + growth) × (1 + overlay overhead), rounded up to the next carrier tier. The busy-hour rate is applied only to concurrent users, then inflated for growth over the contract term and for tunnel encapsulation. Rounding up to a carrier tier turns the figure into something you can actually order.
Branch circuits are contracted for two or three years, so a 20% sizing error is either a permanent overspend or a permanent congestion ticket queue.
This calculator takes 5 inputs: Users at the site, Busy-hour rate per user, Concurrent users, Growth allowance, Overlay and tunnel overhead. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.