On-call number reliability Your on-call service deserves clear answers.
What happens when nobody answers, when the application is unavailable, and how can you look up calls?
01 · No answer
The call does not stop at the first phone.
You set what happens next once, for each rota. The phones of the people on call ring one after another or all at once, and each confirms the call with a keypress: voicemail cannot answer in their place.
If nobody answers, your fallback applies: a voicemail with a notification to the team, reception, another rota or a simple message.
1shift rings the right people, in the order you set. It cannot make someone pick up or reach a phone with no signal: that is what the fallback is for. And so that there is always someone to call, slots with nobody on call are flagged to you in advance.
Spot the slots still to fill →Routing strategy
Ring callable holders one after another — each for the set duration — until someone answers.
Ring duration
Require call confirmation
Ask the on-call person to press a key to accept before connecting the caller. Keeps voicemail and answering machines from swallowing the call.
On-call not reached
Capture voicemail02 · Continuity
Your calls do not depend on our application.
Two phone servers, a primary and a backup, always hold a copy of your rota. If our application or one of the servers goes down, the call still gets through.
- Two servers, always readyEach has received your rota and can take the call.
- Continuously monitoredWe check that each server is reachable and up to date.
- Isolated between customersOne customer’s calls cannot go out through another customer’s line.
copied in advance
If one goes down, the other takes the call.
incoming call
For your IT department
- The servers receive call destinations in advance, for the next seven days by default. A call is routed using what the server already knows, without querying the application.
- Every rota change triggers a server update, and a renewal takes place every twelve hours. The look-ahead period and renewal are defaults, configurable per organisation. A replacement does not wait for the periodic renewal to be synchronised.
- During an application outage, the last received rota applies only within the period already transmitted. A sign-up or replacement must be recorded when the application returns, then synchronised with the servers.
- Failover to the backup server is set up with the telephone operator during activation.
03 · The record
Review the path of calls after the shift.
Every incoming call leaves a record, answered or not: who called, who was expected, who answered and the outcome. Events are kept by the telephone servers and sent to the application when it becomes available again.
This is a call log, not an audio recording of conversations. Voicemails left by callers can be played in the application.
Monday 21 September
- Caller
- 02 511 42 90
- Schedule
- IT on-call
- Assigned to
- Alice Martin
- Ring duration
- 0:31
- Talk duration
- 3:41
- Started
- 21 September 2026 02:40
04 · Your data
Hosted in the European Union, accessible to the people you choose.
Data hosted in the European Union (Germany), with Hetzner.
Two-factor authentication available for every account.
View, assign or manage, for each rota. An office assistant can fill the rota without changing the routing.
The application processes phone numbers and voice messages. They stay within your organisation’s context and are not used for anything else.
This website’s privacy policy covers your contact request. Information about processing in the application is provided before activation.
Privacy policy →Frequently asked questions
What people ask us about reliability.
Can I keep my phone system and operator?
Your other lines remain unchanged: your phone system relays the on-call number to 1shift. Requirements depend on your installation and operator; we review them with you before activation.
Do you offer a service level agreement?
Service commitments and support arrangements are agreed with you before going live, based on your requirements, and set out in your commercial proposal. The mechanisms described on this page do not in themselves constitute a contractual availability commitment.
Come and see how a call travels through 1shift.
In thirty minutes, we start from your current rota and your current line, and show you what that would look like in 1shift.