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Lumen voice alternative

Keep your phone system. Change the carrier underneath. 

Lumen has stopped selling new enterprise voice. If you’re mapping your options, here’s the short version: Sinch owns the U.S. network your calls would run on, connects into Teams, Genesys, Webex, and Five9 without touching your platform, and puts a dedicated team on your number ports.

Talk to a voice expert

Run us in parallel with your current service first. No contract to break, no obligation to move.

Image for Keep your phone system. Change the carrier underneath. 

The network behind the networks

Tier 1 carriers hand us their traffic

Tier 1 carriers trust Sinch to carry large volumes of their own calls. That’s the part most providers can’t say: when your carrier is the carrier other carriers buy from, there’s no one upstream between your call and the network.

250 billion
Minutes carried per year
160 million+
Numbers on the network
99.99%
Guaranteed uptime, SIP Trunking
Since 2004
Operating our own U.S. voice network

Four reasons enterprises move their traffic here

Your calls run on a network we own

Not a resold trunk. You get direct control over routing, quality, and troubleshooting – which is why other carriers hand us their traffic.

An uptime commitment you hold directly

99.99% uptime on SIP Trunking, backed by a network operations center staffed 24/7. Add the compliance layer enterprise voice needs: STIR/SHAKEN caller ID authentication, E911, Kari’s Law and RAY BAUM’s Act support, and TLS/SRTP encryption.

Your ports get a dedicated team

Your number transfers get a named team, not a shared support queue. We’re an officially registered toll-free provider, so we handle transfers, vanity numbers, and fraud protection directly.

Voice is a growth business here

We’re investing across enterprise telephony, contact center, application-centric voice, and agentic AI voice. It’s a core business, and it’s growing.

Depth, not just breadth

Built deep in the market you actually operate in

Plenty of providers will sell you a country count. That matters if your calls cross borders. If your business runs on U.S. numbers across multiple U.S. sites, what matters is how much of this country your carrier reaches directly, and how few hands your call passes through to get there.

  • 95% of the U.S. population covered directly 

  • 43 geo-redundant points of presence across North America 

  • Consistent emergency calling across every one of your sites 

Image for Built deep in the market you actually operate in

Emergency calling

We don’t just route 911. We own the network.

Sinch delivered more than 52 million 911 calls in 2025. Emergency services aren’t a feature we bolted on through a partner: we operate the 911 network, which is why our quality of service holds up on the calls that matter most.

For hospitals, county offices, financial branches, and any business running multiple locations, that’s the difference between a compliance checkbox and infrastructure you can stand behind.

Image for We don’t just route 911. We own the network.
“We rely on Sinch for stability, scale, and support across every channel we deliver. Voice, messaging, numbering, dynamic E911 – practically everything we offer runs through Sinch.”
  • Vested Networks serves more than 1,200 U.S. businesses, from single-line offices to county governments and major medical providers, on Sinch SIP trunking, numbering, toll-free, and dynamic E911.
Evan Huff CEO and Founder, Vested Networks
Read the full story

A Leader in the 2026 Gartner® Magic Quadrant™ for CPaaS

Named a Leader for the fourth consecutive year.

Your phone system doesn’t move. Only the carrier does.

Bring Your Own Carrier separates the carrier layer from the platform layer. Keep Teams, Genesys, Webex, or Five9 exactly as they are, keep your numbers, and put your per-minute costs on a separate, benchmarkable invoice instead of buried in a bundle.

Running something more specialized? Tell us what’s in place and we’ll say honestly whether it’s a straight carrier swap or a project that needs more planning. 

  • Operator Connect for Microsoft Teams 

  • Modern IP systems, or older equipment through a gateway 

  • Centralized management and consistent emergency calling across locations 

  • Ready for AI-powered and agentic voice when you are 

Microsoft Teams
Genesys 
Webex Calling
Five9
Zoom
Cisco
NICE
3CX
On-premises PBX via gateway
Microsoft Teams
Genesys 
Webex Calling
Five9
Zoom
Cisco
NICE
3CX
On-premises PBX via gateway

Test first. Commit later.

You don’t have to pick between waiting it out and ripping everything out. Run real traffic across our network while your current service stays exactly where it is, and decide from evidence.

One date sets everything else – whether you’re planning a transition now or booking a check-in for later.

Point a slice of real traffic at the Sinch network and judge call quality, reliability, and operational fit yourself.

A dedicated team maps your locations and number inventory into a porting, testing, and cutover plan. No surprises mid-migration.

Numbers port with no service interruption. Your platform never moves.

Map your timeline with us
Image for Test first. Commit later.

Five questions to ask every provider on your list

Including us. Print this, take it into your next three calls, and see who answers plainly.

Ask this 
Why it matters 
Our answer 
Do you own the network, or resell someone else’s? 
Every intermediary is another place a call can degrade. 
We own and operate it. Tier-1 carriers carry traffic on it. 
What uptime will you guarantee in writing? 
A number in a contract beats a number on a website. 
99.99% on SIP Trunking, with a network operations center staffed 24/7. 
Who handles emergency calling? 
Many providers route 911 through a third party. Ask whose network it is. 
Ours. More than 52 million 911 calls delivered in 2025. 
Who does the porting, and how do I reach them? 
Porting is where migrations stall. A ticket queue is not a plan. 
A dedicated team on your transfer, not a shared queue. 
Can I test you before I commit? 
Anyone confident in their call quality will let you hear it first. 
Yes. Run real traffic in parallel while your current service stays untouched. 

Questions we get

Most of these come up in the first call. Here they are up front.

No, and we won’t ask you to break an active contract. Lumen has said it will support existing agreements. The reason to start now is practical: porting, testing, and cutover take planning, and it’s easier to do that before a renewal date sets the timeline for you.

Yes. Numbers transfer through the standard portability process, and because we’re an officially registered toll-free provider, we handle transfers, vanity numbers, and fraud protection directly. A dedicated team runs the transfer to keep disruption down. 

In most cases, yes. Sinch works with Teams, Genesys, Webex, Five9, Zoom, NICE, and Cisco, and connects to Teams calling through Operator Connect. Depending on your architecture, you keep the calling or contact center platform you already run and change only the carrier underneath. More specialized legacy setups need extra planning. 

Not one-for-one. If you pooled calling capacity across locations, or ran legacy and IP lines together while migrating site by site, this is a bigger project than a standard carrier swap. Raise it in the first conversation and we’ll scope it honestly rather than discover it halfway through. 

Fair question to ask anyone right now. Our U.S. voice business has run since 2004, carries roughly 250 billion minutes a year across 160 million+ numbers, and delivered over 52 million 911 calls in 2025. Voice is a growth area and an area of active investment for Sinch. 

It depends on locations and number volume, which is why we scope before quoting a timeline. A single-site trunk replacement is nothing like a multi-country port of tens of thousands of numbers. What we commit to is a parallel evaluation you can start now, and a dedicated team on the port itself. 

References to Lumen’s end of sale reflect Lumen’s own public announcements. Nothing here is advice to break an existing contract.

Lumen, Microsoft Teams, Genesys, Webex, Five9, Zoom, Cisco, and NICE are trademarks of their respective owners, used for identification only.