OptionalonAction when the destination does not answer within timeout. Default: 'return'.
OptionalonAction when the destination is busy. Default: 'return'.
OptionalonAction when the destination declines (confirm gate failed, AMD machine, or rejection). Default: 'return'.
OptionalonAction when a protocol-level error occurs on the destination leg. Default: 'return'.
OptionalvoicemailSIP URI or HTTP URL for voicemail. Required when any disposition value is 'voicemail'.
Per-outcome fallback actions when a transfer does not complete normally.