Hidden Treasures - Recycling Large-Scale Internet Measurements to Study the Internet's Control Plane
(2019)
Standards govern the SHOULD and MUST requirements for protocol implementers for interoperability. In case of TCP that carries the bulk of the Internets' traffic, these requirements are defined in RFCs. While it is known that not all optional features are implemented and nonconformance exists, one would assume that TCP implementations at least conform to the minimum set of MUST requirements. In this paper, we use Internet-wide scans to show how Internet hosts and paths conform to these basic requirements. We uncover a non-negligible set of hosts and paths that do not adhere to even basic requirements. For example, we observe hosts that do not correctly handle checksums and cases of middlebox interference for TCP options. We identify hosts that drop packets when the urgent pointer is set or simply crash. Our publicly available results highlight that conformance to even fundamental protocol requirements should not be taken for granted but instead checked regularly.
In recent years, the amount of traffic protected
with Transport Layer Security (TLS) has significantly increased
and new protocols such as HTTP/2 and QUIC further foster
this emerging trend. However, protecting traffic with TLS has
significant impacts on network entities. While the restrictions for
middleboxes have been extensively studied, addressing the impact
of TLS on clients and servers has been mostly neglected so far.
Especially mobile clients in emerging 5G and IoT deployments
suffer from significantly increased latency, traffic, and energy
overheads when protecting traffic with TLS. In this paper,
we address this emerging topic by thoroughly analyzing the
impact of TLS on clients and servers and derive opportunities
for significantly decreasing latency of TLS communication and
downsizing TLS management traffic, thereby also reducing TLSinduced
server load. We propose a protocol compatible redesign
of TLS session management to use these opportunities and
showcase their potential based on mobile device traffic and mobile
web-browsing traces. These show promising potentials for latency
improvements by up to 25.8% and energy savings of up to 26.3%.