This API is available on Firefox OS for internal applications only.

The onerror event handler of the TelephonyCall interface is a reference to a function to be called when the call does not succeed due to error. This is being obsoleted as it is very similar to TelephonyCall.ondisconnected, but semantically more narrow and therefore not as useful.

The event handler is called with a CallEvent as its only parameter.


// Telephony object
var tel = navigator.mozTelephony;

// Place a call
tel.dial("123456789").then(function(call) {

  call.onerror = function(e) {
    console.log('Your call has failed with an error ' +;


Specification Status Comment
Web Telephony Draft Draft.

Browser compatibility

For obvious reasons, support is primarily expected on mobile browsers.

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support No support No support No support No support No support
Feature Android Firefox Mobile (Gecko) Firefox OS (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support 12.0 (12.0) 1.0.1 No support No support No support

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API B2G Certified DOM DOM Reference Firefox OS Mobile Non-standard Obsolete onerror Property Reference Référence Telephony TelephonyCall