Movie and TV streaming site Netflix has become the biggest source of internet traffic in the US, accounting for 29.7 percent of downstream Internet traffic during peak times, according to a new research.

The Sandrive Research report said that in October, Netflix accounted for 20 percent of peak downstream traffic. However, according to experts, the growing trend of streaming is likely to cost more to internet service providers in terms of upgrades to satisfy demand.

Not only peak times, Netflix accounted for a 22 percent average traffic share over a 24 hour period even at off peak hours. Streaming of video and audio is responsible for 49.2 percent of peak time internet congestion in the US, the report said.

Meanwhile, TV service providers are starting to wage their own subtle war on Netflix and other bandwidth-intensive services. For example, a bandwidth caps of 150 GB per month for DSL customers has been enforced by AT&T. The company has also imposed a cap of 250 GB per month for U-Verse customers. Users are charged $10 for every addition 50 GB once they exceed the cap three times.

Although not Netflix, the BBC iPlayer has bagged a 6.6 percent share of peak traffic in Europe, said Sandvine. In Europe, movie and TV streaming account for 33.2 percent of internet traffic, and the percentage has been rising for the past three years, the report added.