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How to call a user

Voximplant supports calls from any endpoint to the cloud and from the cloud to any endpoint including non-PSTN endpoints: Web pages with our Web SDK, Android and iOS devices with our mobile SDKs, and SIP-enabled software or hardware devices. For this purpose, we create users and use their credentials.

Users can be created programmatically via the HTTP API or the control panel: switch to the Users tab in the application and either click Create in the center of the screen or Create user in the upper right corner.

So, once there is a user in our app, we can call him or her using the callUser method in the scenario associated with the same application. The method can trigger the CallEvents.Failed event after 60 sec.

One user or two?

Note that this user should be logged in on some Web/Mobile client. If you call to the cloud from PSTN, one user is enough. If you want to call this user without using PSTN, you have to create another user in the same application and initiate a call from it; in this way, one user will call another. Similarly, both users should be logged in on different clients.


Use the following parameters to set up your call:

  • username is the name of the Voximplant user to call.
  • callerid is what will be displayed to the called user. Normally it's some phone number that can be used for callback. IMPORTANT: test numbers rented from Voximplant can't be used as CallerID, use only real numbers.
  • displayName is the name of the caller to be displayed to the callee. Normally it's a human-readable version of CallerID, e.g. a person's name.
  • video specifies if the call should have video support. Please note that prices for audio-only and video calls are different!

Find all the available parameters here.

Usage sample

Usage sample

Put this code to your Voximplant scenario


This is how you can call users of the application from within SDKs. And don't forget to request microphone permission if it hasn't been already given by the user.

call user from within SDK

call user from within SDK