Dear RIPE community, we are a team of researchers from ICSI Berkeley, TU Berlin, TU Munich, Internet Initiative Japan and UC Berkeley jointly working on a project to assess the effects of IPv4 address exhaustion. As part of our research, we conduct a survey among network operators. The goal of this survey is to better understand the degree of IPv4 scarcity that ISPs face and which measures are taken to combat it (IPv4 Carrier-Grade NAT deployment, IPv4 address markets, and IPv6 transition mechanisms). If you work for an ISP that connects end-users to the Internet, we would greatly appreciate your response. To participate, please visit http://natsurvey.icsi.berkeley.edu/ (answering should take less than 5 minutes, all questions are explicitly optional). We will make anonymized results of this survey available to the public in early 2016. Thank you very much for your support! If you have questions or concerns, please feel free to contact me directly at prichter AT icsi DOT berkeley DOT edu.