Blog Post

For ISPs Skype sounds better on iPads, worse on MacBooks

From an ISP’s perspective, making Skype (s msft) calls on an iPad (s aapl) is far better than doing so on a MacBook Pro. Making calls via an Android (s goog) or Windows Phone 7 (s msft) handset falls somewhere in the middle when it comes to adding to the congestion of the overall network, according to research out Monday from Mu Dynamics.

Mu Dynamics makes a collection of products designed to show what happens when an app scales on infrastructure, from networks run by ISPs to servers running web apps in the clouds. As part of its efforts to sell more products, it’s embarking on a mission to educate both ISPs and app developers about how the software people are building today can affect the infrastructure if the software is widely adopted. Mu provides the equivalent of an infrastructure stress test.

For its latest test, Mu looked at Skype’s voice calling and chat functions across a bunch of different devices running different operating systems. A previous test looked at how Netflix traffic affected networks when compared to YouTube (s goog) or other streaming video traffic. Netflix (s nflx) didn’t do well.

For the Skype test, Mu’s service made multiple calls to the Skype test number that lasted the same amount of time, measuring the data transmitted and the behavior of the packets to figure out how it would treat an operator, and how much of a data impact it would have on a consumer. Neither voice calls nor messaging had much of a data impact for the consumers, although in both cases running it on Mac OS X consumed the most data.

The results of this and other Mu Dynamics’ studies show how developers need to consider the infrastructure they’re running on as they design for the web. At the same time, the infrastructure providers have to understand the types of applications programmers are building and their consumers are consuming. In the case of server infrastructure, the end customers are the developers, which makes the relationship simple: the infrastructure or platform provider seeks to make developers’ lives easier so they will build on their services.

But in the case of ISPs, developers and the ISPs are both selling to end-consumers, and neither has a direct reason to talk to each other or work together to understand how the applications affect the infrastructure and vice versa. In a competitive broadband market, this might not matter because consumers could switch their ISPs easily if their Netflix or Skype ran poorly. However, because broadband access is essentially a duopoly and ISPs may have an economic interest in making sure certain apps run poorly, maybe Mu Dynamics’ can help provide — if not an incentive — at least information that could help booth sides meet in the middle.