Tango or square dance?: how tightly should we integrate network functionality in browsers?

The question at which layer network functionality is presented or abstracted remains a research challenge. Traditionally, network functionality was either placed into the core network, middleboxes, or into the operating system - but recent developments have expanded the design space to directly introduce functionality into the application (and in particular into the browser) as a way to expose it to the user. Given the context of emerging path-aware networking technology, an interesting question arises: which layer should handle the new features? We argue that the browser is becoming a powerful platform for network innovation, where even user-driven properties can be implemented in an OS-agnostic fashion. We demonstrate the feasibility of geo-fenced browsing using a prototype browser extension, realized by the SCION path-aware networking architecture, without introducing any significant performance overheads.