Vodafone customers using roaming have been reporting problems and broken connections with the service since Christmas -- issues the operator puts down to network congestion and a lack of help from its supplier, Optus.

The operator said that the problems are a result of congestion of international signalling links -- essentially backhaul -- provided by Optus, which Vodafone attributes to the volume of international tourism to and from Australia.

"We've put in a request to get the capacity [from Optus] but we're not getting much joy at this stage ... they've not been particularly forthcoming," a Vodafone spokesperson said.

The operator could not put a figure on the number of customers affected but said around 10,000 of its roughly three million customers are currently roaming.

The Vodafone spokesperson did not expect affected customers to be compensated for the inconvenience.

The congestion issues should ease starting 2 January.

"It will be resolved once people come back from their overseas trips," Vodafone's spokesperson said. "After we get through the New Year, it will change the profile of the network."

The spokesperson denied the problems were a result of inadequate forecasting on Vodafone's behalf.

Vodafone claims the roaming problems will not be repeated once it upgrades its network to HSPA, the faster form of 3G. The operator announced in December that it intends to move to HSPA by Christmas 2008, giving users access to a theoretical maximum download speed of 3.6Mbps.

Have you experienced difficulties with your mobile service over the holiday period? Let us know using the comments below.