What happens behind the scenes when someone calls a cloud phone number?
Summary
The call crosses the regular phone network to the provider that holds your number, and the provider's servers decide where it goes. They check your business hours and routing rules, then ring whoever is signed in on a mobile app, a desktop app, or an IP desk phone, over the internet. Because the numbers and rules live with the provider, not in your office, calls keep arriving even when your office connection is down, and you can send them somewhere else.
Following one incoming call
A customer dials your main number from a cell phone. The call starts on the ordinary phone network, which hands it to the cloud provider that holds that number. The provider's system looks up your rules: is it within business hours, should the auto attendant play, which ring group gets it. It then rings the people in that group wherever they are signed in, either all at once or one after another. If no one answers, the call moves to another teammate, forwards to an outside cell number, or drops into voicemail.
None of this requires a technician. An admin edits the rules in a web portal and the change usually takes effect right away. Some services go further on who rings: Ooma Office's Multi Ring, for instance, can ring an office phone, the mobile app, and an outside device on the same call.
Calling out
When an employee places a call from the app, it travels over the internet to the provider, which connects it to the phone network and shows your business number as the caller ID. That is how people can use personal phones for work without handing out their own cell numbers. Call logs, and recordings on plans that include them, stay with the provider, and disabling an account cuts off that person's access to the business number.
When the office goes offline
Office devices reach the provider through your internet connection, so a local outage or power cut stops them. The FCC notes that VoIP may not work during a power outage or when the internet connection fails or becomes overloaded, and Comcast Business says the same of its own cloud PBX, including calls to 911.
- Incoming calls still reach the provider, because your number lives there, not in your building.
- If your service forwards calls to cell phones or another location when your devices cannot be reached, those calls still get answered.
- Some providers build in extra resilience. Zoom advertises a 99.999% uptime SLA for Zoom Phone and a failover option it calls Local Survivability.
Getting 911 to the right address
A cloud phone can be used anywhere, so the address sent with a 911 call comes from what you registered with the provider. For services that move, the provider must send an automatic location where that is technically feasible and otherwise use your registered location, which you must be able to update at will. If the provider detects a 911 call from somewhere other than the registered address, it has to prompt you for a new one or update it itself. An office move or a new remote worker means a new registered address.
Sources
- fcc.gov/consumers/guides/voip-and-911-service
- ecfr.gov/current/title-47/chapter-I/subchapter-A/part-9/subpart-D/section-9.11
- ooma.com/small-business-phone-systems/features
- business.comcast.com/learn/phone/voiceedge-virtual-pbx
- zoom.com/en/products/voip-phone
Related on this site
- What does a business phone system actually do for a small company?
- What is VoIP, and how is it different from a regular phone line?
- Is a cloud PBX any different from hosted VoIP or a cloud phone system?
- How does a business phone system decide who answers a call?
- How much internet speed do VoIP calls actually need?
- Will 911 know where you are if you call from a VoIP phone?
Written by Kaz (pen name). Figures are copied from providers' published pricing pages on the dates shown. We have not used these products. Corrections: contact form.