Uptime SLA
An uptime SLA is a contractual target for the percentage of time a named service stays available, plus how outages are counted and what follows if the target is missed.
An uptime SLA is the availability target inside a supplier contract. It commits a named service, typically a leased line or hosted platform, to stay reachable for a stated percentage of the measurement period. Wanzo publishes a 99.9% uptime SLA on its connectivity services. The clause should also define how an outage is timed, where the check is made, and what you receive if the month misses the target.
When the line drops, email, payments, bookings and AI workflows stop with it. Your provider should log every incident against the monthly percentage and send a report you can read without a network engineer. Response time sits beside uptime, not inside it. Wanzo's four-hour commitment covers how quickly an engineer begins work. Ask where they take the measurement. A check at the carrier's exchange won't see a failed router in your comms cupboard.
A connection that's still answering a basic check can be too slow for Microsoft 365 or VoIP, and the SLA still counts it as available. Short drops below the minimum incident length never enter the percentage. Credits on next month's bill don't replace lost trading time. Fibre faults, scheduled work and kit on your side of the demarcation point are commonly excluded. One circuit for the whole office leaves no fallback; a second path or SD-WAN is what keeps the working day going.
When it matters
- →Cloud systems, payments or phones stop when the connection drops.
- →You need to know where the provider measures the 99.9%.
- →A single circuit is the only path for the whole office.
- →Last month's outage produced a credit but no operational change.
Related terms
Uptime SLA: common questions
What is an uptime SLA?
An uptime SLA is the part of a service contract that sets how much of the time a named service must stay available, as a percentage of the measurement period. It should also say what counts as an outage and where that outage is detected. On connectivity, the named service is usually the leased line or managed circuit. Credits are the typical remedy if the month misses. They do not repay lost trading time, so how the connection is designed still matters.
How is uptime measured in an SLA?
Most providers calculate uptime from their own monitoring, not from the moment you noticed the fault. The clock starts when their system records the service as down, and stops when they mark it restored. If you have to raise a ticket before the incident counts, evening and weekend failures can sit outside the percentage until someone reports them. Confirm that monitoring runs overnight and that restoration is confirmed by the same probe that detected the drop.
Does 99.9% uptime mean the service never goes down?
No. 99.9% is a monthly allowance of downtime, not a promise of uninterrupted service. Wanzo publishes 99.9% on its connectivity services, with 24/7 monitoring and a four-hour response when the circuit needs attention. The figure doesn't tell you much until you know what counts as down, which kit is in scope, and which events are excluded. Dual connectivity or SD-WAN is what reduces the chance of a lost working day.
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