Phone API Reference - Core - digium.phone - Call Status Object

If a handler is passed to call-related actions, that handler is called whenever the state of the call changes.

The handler is called with one argument, a call status object with the following fields:

• state - SIP state of the call. One of
  "CALLING", "INCOMING", "EARLY", "CONNECTING", "CONFIRMED", "DISCONNECTING", "DISCONNCTD".

• accountSlot - Identifier for the line the call is coming in on.

• callHandle - Identifier for the call. This will match the call handle returned by digium.phone.dial, for example.

• remoteInfo - SIP url for the remote end of the call.

• remoteContact - SIP contact header for the remote end of the call.

• lastStatus - Most recent SIP status code associated with the call, or "0".

• lastStatusText - Most recent text associated with status code.

• mediaStatus - Describes the current audio data flow. 
  One of "none", "active", "local_hold", "remote_hold", or "error".

• headers - Object mapping SIP headers to their values.

However, if there's an api-level error (e.g., the callHandle is invalid, you are trying to make a call when there's already an active call, etc.), these are available instead:

• state - Has the value "ERROR".

• callHandle - Identifier for the call.

• errorText - Human readable error message (not for display to end users).