The country's largest ISP, Xtra, is reviewing its JetStart DSL package and may consider including a data cap on the service.
JetStart is Telecom's flat rate DSL service that runs at 128Kbit/s. The flat rate differs between ISPs, but Xtra charges $64.90 per month. A number of reseller ISPs have initiated download caps because of a handful of users taking full advantage of the service.
Xtra spokesman Matt Bostwick says it is early days yet and that some kind of data cap is one option. "But it's only part of the review."
Bostwick is keen to avoid interfering with the vast majority of users who don't use several gigabytes of traffic each month.
"This is a path a number of industry players have gone down and we have to look at it."
Bostwick says Xtra has already begun to enforce its current terms and conditions which include a "no server" clause for JetStart users, some of whom were serving files via file sharing programs like KaZaA and Morpheus.
"We're also keen to talk to those users who are at that high end to see if there isn't room for some kind of service targeting their needs," says Bostwick. He cites the JetStream game servers as a good example of this.
"There we know exactly what sort of traffic to expect so we can set up a service to meet that need."
Quicksilver is the latest ISP to introduce a cap, restricting the service to 7GB a month, according to managing director Matthew Hobbs.
"There aren't a lot of them using the service to that level but there are enough doing it to make it unprofitable for us."
Hobbs says Quicksilver is currently looking at moving the cap to 10GB a month, although he says the main impact of the plan is from simply having a cap in the first place.
"It lets them know that they can't do that here, so they tend to go elsewhere." Hobbs says he wants to avoid impinging on the experience of "regular" users.
Paradise, one of TelstraClear's ISPs, also has a cap on JetStart usage, set at 10GB a month. Downloads that exceed that point are charged at 20 cents per megabyte for international traffic or 2 cents per megabyte for national. Quicksilver users aren't permitted to exceed the download limit each month.