T-Mobile defends block on cheap call firm

T-Mobile has denied blocking customers from mobile voice-over-IP vendor Truphone to prevent them making cheap calls.

Truphone offers a software module that allows users of Wifi-enabled phones to make VoIP calls when they are within range of a network. Calls to other Truphone users in Wifi range are free, as are calls to fixed VoIP phones using the SIP protocol.

Users also get a Truphone number that gives them cut-price national international roaming calls. T-Mobile admits not connecting calls to Truphone numbers but says this is because the VoIP company is demanding too high a termination fee – the charge an operator pays for a call to a rival network.

The fee is higher for a mobile operator than for a fixed-line telco because the running costs of a cellular network are higher. Simon Marks, head of corporate communications at T-Mobile, said Truphone had been offered the same termination fee that BT gets, adding: "[Truphone's] costs are extremely low."

Marks said T-Mobile does not see VoIP as a threat and had embraced it more than any other operator. "We have had not blocked handsets from using Voice over IP, unlike some of our rivals," he said, referring to Orange and Vodaphone, which blocked Truphone use on Wifi-enabled Nokia N95 handsets sold under their brand.

And he pointed out that T-Mobile allowed VoIP to be used over its Web'n'Walk flat-rate mobile data services. T-Mobile is also an investor in the Jajah web-call service.

Marks said: "The rate Truphone is asking cannot be fair because they mean we would have to charge more. They want our customers to subsidise their customers' cheap calls."