This January 2020 issue starts the fiftieth volume of Computer Communication Re- view. This marks an important milestone for our newsletter. This issue contains four tech- nical papers and three editorial notes. In C- Share: Optical Circuits Sharing for Software- Defined Data-Centers, Shay Vargaftik and his colleagues tackle the challenge of designing data-center networks that combine optical circuit switches with traditional packet switches.

In our second paper, A Survey on the Current Internet Interconnection Practices, Pedro Marcos and his colleagues provide the results of a survey answered by about hundred network operators. This provides very interesting data on why and how networks interconnect. In A first look at the Latin American IXPs, Esteban Carisimo and his colleagues analyze how Internet eXchange Points have been deployed in Latin America during the last decade.

Our fourth technical paper, Internet Backbones in Space, explores different aspects of using satellite networks to create Internet backbones. Giacomo Giuliari and his colleagues analyse four approaches to organise routing between the ground segment of satellite networks (SNs) and traditional terrestrial ISP networks,

Then, we have three very different editorial notes. In Network architecture in the age of programmability, Anirudh Sivaraman and his colleagues look at where programmable functions should be placed inside networks and the impact that programmability can have on the network architecture. In The State of Network Neutrality Regulation, Volker Stocker, Georgios Smaragdakis and William Lehr analyse network neutrality from the US and European viewpoints by considering the technical and legal implications of this debate. In Gigabit Broadband Measurement Workshop Report, William Lehr, Steven Bauer and David Clark report on a recent workshop that discusses the challenges of correctly measuring access networks as they reach bandwidth of 1 Gbps and more.

Finally, I’m happy to welcome Matthew Caesar as the new SIGCOMM Education Director. He is currently preparing different initiatives, including an education section in CCR.

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.