The practical answer. For a few essential tasks, first investigate a 4G or 5G connection tested inside your premises. For sustained, demanding use, compare a second fixed connection whose failure path is genuinely separate. Two subscriptions are useful only if they cover the relevant failures and let people continue working.
Identify the work that must continue
List tasks that cannot wait, together with simultaneous users: receiving calls, entering orders or opening customer records. Large transfers and updates can be deferred during an outage. Test your hosted applications directly; a working website does not prove that your business application or phone system is protected.
If only Wi-Fi is affected, first compare wireless and wired access. Buying another Internet connection will not fix a local wireless fault.
Compare the options on site
| Option | Appropriate starting use | What to test |
|---|---|---|
| Phone hotspot | Temporary access for one workstation | Phone availability and actual application access. |
| 4G/5G router | Priority tasks across the business network | Indoor reception, concurrent use, data allowance and compatibility. |
| Second fixed link | Larger or prolonged workloads | Physical route, shared equipment and service commitments. |
Do not choose 5G merely because it has the newer name. Compare the service delivered at your address, using the intended subscription and users. Ask what happens at the data allowance limit: reduced speed, extra charges or disconnection depends on the contract.
Are two operators independent enough?
Not if they share the failed component. Two fibres may pass through the same duct. Both connections may depend on one router or power supply. The French telecoms regulator Arcep recommends checking dependencies and testing failover. Its guidance is in French.
Have the proposal name the failures it covers: operator outage, damaged cable, failed router or loss of building power. A second Internet subscription alone covers none of these automatically.
Test the return to work, including failback
Arrange an authorised, controlled interruption compatible with operations. Measure from disconnection to the first successful call and the first saved business transaction. Repeat with the expected user count, then test return to the primary link.
Read the diagram as text
INITIAL INFRA / CONTINUITY Two links. Check the shared dependency. Concept diagram: adapt it to your installation. Devices + calls Workflows to test Shared router Fibre Mobile backup The router and its power supply can still fail together. Two subscriptions do not remove every shared dependency. Test calls, applications and the return to the primary link.
Record link availability separately from successful tasks. If web access returns but calls do not, telephony has failed that test. Flag services restricted to an approved public IP: the backup link may use a different address. Ask the provider to validate remote access and address requirements for the chosen mobile plan rather than assuming it behaves like the fibre service.
Use this worksheet
Internet failover log
Plan the test with the network owner. Record date, outage time, user count and acceptable recovery delay. Prepare before interrupting a critical installation.
Complete the worksheet
Nothing is sent or saved automatically. Download your answers before leaving the page.
Useful recovery time runs from the outage to essential work resuming. A working web page does not validate calls or the application.
Automatic failover can interrupt existing sessions. Record whether calls, VPNs or application sessions must reconnect, who receives the alert, and whether failback disrupts them again. Decide which tasks remain deliberately unavailable and tell staff how to work during that period. Re-test after moving premises.
What belongs in the quote?
Identify equipment, subscription, installation, configuration, acceptance testing and ongoing monitoring. Include data limits, escalation contacts and who checks the backup connection between incidents. Give Initial Infra your essential applications, simultaneous users and existing access details to scope the work.