Introducing cloud telephony: what to settle first

Inventory numbers and connections

List main numbers, direct dial numbers and specialist devices. Ask specifically about door entry systems, fax, alarms or connections that rarely attract attention during office work. For specialist uses, verify suitability with the device and connection providers. A working desk-phone call does not establish that those devices will work.

Coordinate number transfer and contract end dates with the providers involved. Record which connection must remain available until cut-over is confirmed. The phone system and the telephone service provider can be separate services. In 3CX, a correctly configured SIP trunk connects the system to the public telephone network; supported providers help with a coordinated setup.

Test call flows on paper

Example: a main number first reaches reception. If unanswered, two other people are called; outside office hours, callers hear an announcement. Walk through the flow with the team. What happens during holidays, when a line is busy or when the office closes early? Record who may change announcements and assign cover.

Alongside headcount, identify simultaneous calls and requirements such as queuing or transfers. Not everyone calls at once, while a small reception team may handle several calls at busy times. Use existing usage data and a pilot to justify the choice. Licence scope and additional features need to match the specific offer.

Check the network and devices together

Test typical calls in the office, over Wi-Fi and at intended home-working locations. Check audio in both directions, transfers, headsets and how apps ring. Repeat under normal network load. A high download result from one speed test does not fully describe call quality.

Network rules depend on the deployment. 3CX documents different requirements for SIP trunks, apps and SBC connections, together with checks using its Firewall Checker. Do not copy a generic port list from someone else's installation. Have rules configured and documented for your deployment.

Availability during an outage

Discuss office internet loss, power failure and telephony-service failure separately. A second internet connection addresses a different scenario from a provider-side redirect to a mobile number. Test the agreed fallback and name someone who can activate it. Confirm emergency-calling arrangements and location information with the connection provider for each intended location; do not make unannounced test calls to emergency services.

Pilot and cut-over checklist

• Reconcile main numbers, direct dials, specialist devices and existing contract details.
• Include reception, office and mobile staff in the pilot group.
• Test external calls, outbound caller ID, transfers and absence handling.
• Approve announcements, office hours and responsibilities for changes.
• Document fallback arrangements, contacts and the response to cut-over problems.
• Retest key call flows after cut-over and remove obsolete access in a controlled way.

Make the enquiry specific

Provide locations, user numbers, phone numbers, required call flows and current devices. Add desired features and the intended migration period. These details provide a basis for a useful pilot. Record the included setup, support and connection services in the quotation.