In an IP world, the way your phone -- or rather voice, data and video -- bills are compiled is likely to be different to the method of recording and charging for voice calls over the PSTN, says Telecom technology chief Murray Milner.
"We're likely to see fixed costs for connections and application-oriented charges for services such as voice, web browsing and video on demand."
Time, the standard way of working out how much to charge for PSTN calls, will be "a less useful medium for recording -- volume may be the way to do it".
If a customer wants to continue to be billed for voice usage "in today's way", Milner says, "it could be counted in megabytes and converted to equivalent minutes."
Telecom hasn't decided how the billing on the all-IP network will be done, "but we'll do whatever is the industry standard and it's more likely to be by volume -- minutes don't measure how much you're using with video.
"The basic principle in the traditional telephone world is that we deal with a 64Kb/s set rate." In the all-IP world, "each application is totally variable in terms of bandwidth, so volume makes much more sense."
Another aspect that will change is how voice calls are legally intercepted by police and security services.
When such interception is required for voice travelling the IP network, it won’t be difficult to provide, Milner says.
"There's no great difficulty in creating intercept -- there's a standard capability from suppliers."