ZDNET Australia: ...

However, although mobile service will remain unaffected, there is expected to be some impact on Vodafone customers for the period around the changeover. According to Vodafone, no numbers will able to be ported to or from the operator between October 6 and October 13, although all number porting requests will be processed when the IT upgrade is complete.

Vodafone has also asked any users who are likely to need international roaming switched on in early October to put in their request in advance.