Broadband networks such as DSL or cable are used more and more widely for accessing the internet. Over 158 million people worldwide use these networks. By 2011, this number is expected to rise to 477 million. In Germany, over 65 per cent of all internet users are connected to broadband networks at home. In addition, many governments have made it their target to promote universal broadband access.
Broadband networks deliver access to the internet infrastructure and most of the time, bottlenecks to these access networks can be found in the efficiency of the internet. Many popular internet applications, such as voice over IP (VoIP), video on demand, online games and peer-to-peer networks, greatly depend upon the performance qualities of broadband networks.
However, many private customers are ignorant of the characteristics of their broadband connections.
Cable and DSL providers increasingly use middle boxes, such as for example traffic shaper, blocker or firewalls, for the supervision and control of their clients’ data traffic. Middleboxes categorize and manipulate the flow of data from the various applications in accordance with ISP-specific guidelines. And because the guidelines of data traffic management are often influenced by company interests (for example peering agreements between ISPs, which are mutually regulated by contract), indications to middlebox implementation is not at all made known by many ISPs.
This is why today, many end users are not even aware of the existence of middleboxes and can therefore often not imagine their consequences on the performance of internet applications.
Recently, it has been stated that specific access providers in the US secrectly prevented their clients from exchanging data with other users by means of the popular file-sharing protocol BitTorrent. It was determined that these ISPs blocked BitTorrent data flows by sending false protocol packages to communication end-points, which leads to an immediate interruption of the connection. Reports on such blockages started an intensive and far-reaching guideline controversy over acceptable practices in the traffic management of ISPs and the issue of network neutrality among ISPs, user protectors, internet providers and government authorities.
We do not want to discuss the advantages of the various traffic management guidelines here. Neither do we wish to plead for specific guidelines, such as network neutrality, which does not allow for a different treatment of packages by ISPs, on grounds of the communication end-points, nor the used internet application.
The formulation of optimal traffic management guidelines is extremely important and demands the careful consideration of numerous technological, economic and social factors, which are decisive for the future of the internet.
Instead, we want to plead for network transparency. In simple terms, network transparency demands that end users know the characteristics of the access networks they use. This knowledge helps users when choosing their provider. If this transparency existed, end users would know which quality of service they receive, when using different applications such as VoIP or video on demand.
Also, application developers can use such knowledge to specially create their applications in such a way that they run better in the home environment.
Ideally, networks could be created with more transparency through ISPs, in that they disclose how they control their data traffic and where they implement traffic management. However, experience has proven that providers are rather reluctant to disclose such information, even when they are required to do so by state supervisory authorities. Furthermore, information provided by ISPs to their customers is often vague and at best interpretable in many ways, at worst, near-misleading.
For this reason, end users need appropriate mechanisms, with which they can examine information received from their ISPs. With this in mind, we at the Max Planck Institute for Software Systems, have initiated the Glasnost project. Our aim is to enable to draw conclusions on the characteristics of their access networks through direct measurements. The Glasnost system is created in such a way that it approaches numerous tricky duties: It attempts to find out which data traffic is being manipulated and where traffic shapers can be found. Interested readers can carry out the test by visiting the following website: http://broadband.mpi-sws.org/transparency.
Ph.D. Krishna P. Gummadi is the head of the Networked Systems Research Group at the Max Planck Institute for Software Systems in Saarbrücken. Before this, he worked as a research assistant at Microsoft in Redmond, ISCI and Intel in Berkley after completing his internship at the Polytechnische Hochschule Lausanne. Gummadi studied in Madras, India, and at the University of Washington (USA), where he also completed his doctorate.
