For example, an incoming call might reach reception during office hours, then a sales ring group if reception is busy, followed by an approved voicemail or alternate destination. Agree who owns each step and test the unanswered-call case as well as the successful call. A queue or greeting alone cannot guarantee that a customer reaches an available employee.
Simultaneous external calls, internal extensions and telephone numbers are different sizing requirements. Confirm them separately with the platform and voice provider. Retaining an existing handset depends on its exact model, firmware, provisioning and supported PBX configuration; a SIP label does not guarantee every feature works across every vendor.
Security and continuity also need operating owners. Review administrative access, outbound dial permissions, approved remote connectivity, configuration backup and update responsibility. Discuss power and internet failure behaviour with the provider and business owner. Recording, retention, monitoring and customer notifications require an explicitly approved scope and the appropriate business/legal decisions before activation.
Call handling
Reception, queues, hours and unanswered-call behaviour are agreed.
Compatibility
PBX, firmware, licences, phones and provider handoff are checked together.
Ownership
Provider contracts, administration, recording decisions and maintenance have named owners.