Current State:

The vCard and list of voice call numbers that send voice notifications for Operations alerts ( https://support.atlassian.com/jira-service-management-cloud/docs/set-up-sms-and-voice-notifications/#Voice---All-countries ) has only US and China numbers. 

Proposed Future State:

An Australian-based number would be desirable, much like Opsgenie has a dedicated Australian number, in order to improve carrier routing to Australian voice call numbers.