Built to never miss a call.
A redundant network engineered for 99.999% uptime, so your phone works when your business needs it.
What we run so your calls stay up
These are the pieces CallSprout builds and watches: how traffic moves when a site fails, the uptime we engineer for, and the security around every call.
What happens when a site has trouble.
Hardware fails and connections drop, even in well-run data centers. The network is built so one site having a bad day does not take your phones with it.
A site has trouble
One site stops responding, whether from a hardware fault, a power problem or a lost connection.
Traffic moves through the linked sites
Every site is linked to the others, so traffic shifts to the sites that are still running.
Your calls keep going
Your numbers keep ringing and your team keeps dialing out, with nothing to change on your end. When the site recovers, it rejoins the network.
What 99.999% actually means.
Uptime figures all look alike until you turn them into time. Here is the downtime each target allows, side by side.
Figures use a 365.25-day year. At 99.999%, a year allows one hundredth of the downtime that 99.9% does.
Protection for your calls and your callers
Signed caller ID, encrypted calls, emergency calling with a real location, and systems that are watched around the clock.
Read about VoIP security measures- Outbound calls are signed with STIR/SHAKEN, the framework carriers use to verify caller ID.
- Calls are encrypted in transit with TLS.
- Every account has E911, with a dispatchable location for each phone.
- Our servers and network are monitored 24/7.
The connection on your side of the call
Your calls also travel over your own internet. Test it, see which providers serve your area, or let us help you find a better one.
Is your internet ready for business calls?
Run a quick test from this browser. It checks the speed and stability of your connection, then tells you roughly how many calls it can handle at once and whether call quality is likely to hold up.
The test usually takes under a minute. On a fast connection it can use up to about 120 MB of data, so you may want to skip it on a metered mobile plan.
This test measures the path from your connection to Cloudflare's network, not to CallSprout's voice sites. It is one snapshot from one device, so results can change with the time of day, your Wi-Fi signal and whatever else is using the line.
The test runs in your browser against Cloudflare's speed test service, so Cloudflare sees your IP address and the test traffic. CallSprout does not store your results. Privacy policy
See which internet providers serve your address.
Your phone system is only as reliable as your internet. Enter a street address or ZIP code to see the providers that report service there. A second connection from a different provider, or over a different technology, is cheap insurance.
We send an address to the U.S. Census Bureau only to find its census block. We do not store it.
Providers report this data to the FCC themselves. An address search shows the census block around the address, and a ZIP code search shows results by ZIP code, where the speeds are the fastest each provider advertises anywhere in the ZIP. A provider on this list may not serve your exact address, and the speeds are not what you will get. Confirm with the provider before you order.
Need better internet? We'll find it for you.
Your phones are only as dependable as the connection under them. We track down every internet provider that serves your location, ask nearby providers whether they would build out to you, and handle the legwork with you from the first quote to install day. Your agreement is directly with the provider you pick, and our help costs you nothing.
Ask us to find internet for your location- Every available provider at your location, plus the ones open to building out to you
- We coordinate quotes, paperwork and install dates with you and the provider
- You sign directly with the internet provider you choose
- No cost to you for our help
- Want a second line that takes over when one goes down? See Unbreakable Internet
The rest of what keeps your phones dependable.
No hardware closet to babysit, and room to grow.
Add or remove lines instantly, with no hardware changes.
Your phone system runs in the cloud, so there is no on-site box to fail, patch or replace.
High-definition audio with carrier-grade call quality.
Local numbers in 50+ countries, available as an add-on.
Reliability and security, answered.
- What does 99.999% uptime mean?
- It means the network is engineered to be up 99.999% of the time. Over a 365.25-day year, that allows about 5 minutes of downtime. A 99.9% target allows about 8.8 hours over the same year.
- What happens if one of your sites has trouble?
- Each site is linked to the others, so traffic moves through the sites that are still running and your numbers keep ringing. There is nothing for you to change on your end. When the site recovers, it rejoins the network.
- What happens if my office internet goes down?
- Your numbers live in the CallSprout network, not in your office, so they stay reachable when your building's connection drops. If your desk phones go offline, calls can ring the CallSprout mobile app, or a cell phone through find-me/follow-me, as long as you have set that up ahead of time. Your desk phones reconnect once the internet is back. Plan a fallback before you switch
- Are calls encrypted?
- Yes. Calls are encrypted in transit with TLS. Our servers and network are also monitored 24/7.
- How does E911 work?
- Every account has E911 service, and each phone has a dispatchable location, such as a street address plus the floor or suite. When someone dials 911, that location goes with the call so responders know where to go. Update the location whenever a phone moves. Like any internet phone service, 911 calling needs power and an internet connection at the phone, so keep another way to reach emergency services.
- How does STIR/SHAKEN help?
- STIR/SHAKEN is the framework phone carriers use to verify caller ID. Your outbound calls are signed, so the carrier on the receiving end can check that the call came from a provider that stands behind the number. It is one of several signals carriers look at. How a call is labeled also depends on how people respond to your calls. Why a number shows as Scam Likely
- Do you offer network assessments?
- Yes. CallSprout offers network assessments that look at how ready your internet connection and office network are for voice calls, so you know what to fix before your phones move over. Book a network assessment
- Can you help us find better internet?
- Yes, at no cost to you. We look up every provider that serves your location, ask the ones nearby whether they would build out to you, and work through the quotes, paperwork and install with you. You sign directly with the provider you choose. Many businesses also add a second connection from a different provider, so a single outage does not take their phones offline. Ask us to find internet for your location