WebRTC (Web Real‐Time Communication) is the browser standard that lets audio and video flow
directly between a browser and another endpoint, no plugin, no desktop app. Twilio's Voice SDK builds
on WebRTC to let a browser tab act as a real phone, connected to Twilio's voice network.
How it works, at a high level
- Your server asks Twilio for a short‐lived access token scoped to a specific user identity.
- The browser uses that token to register with Twilio's Voice SDK, essentially telling Twilio "this browser tab is ready to make or receive calls."
- An outbound call request from the browser triggers a TwiML Application, server logic that tells Twilio which number to dial and from where.
- Inbound calls to a Twilio number can be routed to that same browser client instead of, or alongside, a regular phone number.
- Audio flows over WebRTC between the browser's microphone/speakers and Twilio's network for the duration of the call.
What you need to make it work
- A Twilio account with Voice enabled and at least one phone number.
- A TwiML Application configured with a voice request URL your server responds to.
- A way to generate access tokens server‐side (Twilio's SDKs support this in most languages).
- A modern browser and a microphone, no other hardware required.
Why teams choose this over a desk phone
Remote and hybrid teams don't always have desk phone infrastructure. Browser calling lets anyone with
a laptop and a Twilio number make and receive calls from wherever they're working, with call logs and
recordings tied to the same account everyone else uses.
Building it yourself vs. using a ready‐made dialer
The steps above are a real, working integration, but they're still an integration: token generation,
a TwiML Application, incoming call routing logic, and a front‐end dial pad all need to be
built and maintained. Kovtel Dialer packages this into a ready interface: pick a
number, click to call, and manage incoming call routing rules, all on your own Twilio account, without
writing the integration yourself.