PRO-COW: Protocol Compliance on the Web

HTTP/1.1, protocol, World Wide Web, compliancy With the recent (draft) standardization of the HTTP/1.1 protocol on the Web, it is natural to ask what percentage of popular Web sites speak HTTP/1.1 and how compliant are these so-called HTTP/1.1 servers. We attempt to answer these questions through a series of experiments based on the protocol standard. The tests are run on a comprehensive list of popular Web sites to which a good fraction of the Web traffic is directed. Our experiments were conducted on a global extensible testing infrastructure that we built to answer the above questions. The same infrastructure will be used to answer questions like the percentage of the traffic flow that is end-to-end HTTP/1.1. Our results show reasons for concern on the state of HTTP/1.1 protocol compliancy and the subset of features actually available to end users.