  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.
