This April 2019 issue contains two technical papers and four editorial notes. In ”On the Complexity of Non-Segregated Routing in Reconfigurable Data Center Architectures”, Klaus-Tycho Foerster and his colleagues analyse whether a data center net- work could dynamically reconfigure its topology the better meet the traffic demand. They explore this problem as a mathematical optimisation problem and seek exact algorithms. The second technical paper, ”Precise Detection of Content Reuse in the Web” ad- dresses the problem of detecting whether the same content is available on different websites. Calvin Ardi and John Heidemann propose a new methodology that enables re- searchers to discover and detect the reutilisation of content on web servers. They provide both a large dataset and software to analyse it.

The four editorial notes cover very different topics. Kc Claffy and Dave Clark summarise in ”Workshop on Internet Economics (WIE2018) Final Report” a recent workshop on Internet economics. In ”Democratizing the Network Edge”, Larry Peterson and six colleagues encourage the community to participate in the innovation that they predict at the intersection between the cloud and the access networks that many refer to as the edge. They propose a plan for action to have a real impact on this emerging domain. In ”A Broadcast-Only Communication Model Based on Replicated Append- Only Logs”, Christian Tschudin looks at the interplay between the append-only log data structure and broadcast communication techniques. He argues that some network architectures could leverage this interplay.

As a reader of CCR, you already know the benefits of releasing the artifacts asso- ciated to scientific papers. This encourages their replicability and ACM has defined a badging system to recognise the papers that provide such artifacts. Several ACM SIGs have associated artifacts evaluation commit- tees to their flagship conferences and encourage their members to release their paper artifacts. Last year, two evaluation of paper artifacts were organised within SIGCOMM. The first one focussed on the papers that were accepted at the Conext’18 conference. Twelve of the papers presented at Conext’18 received ACM reproducibility badges. The second artifacts evaluation was open to pa- pers accepted by CCR and other SIGCOMM conferences. Twenty eight of these papers received ACM reproducibility badges. These evaluations and some lessons learned are dis- cussed in ”Evaluating the artifacts of SIGCOMM papers” by Damien Saucez, Luigi Iannone and myself. We hope that evalu- ating the artifacts will become a habit for all SIGCOMM conferences.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https: //ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.