Internet Background Radiation (IBR) is a mix of unsolicited network traffic mostly generated by malicious software, e.g., worms, scans, which is captured by darknets. In previous work, we extracted signal from IBR traffic that allowed us to identify largescale disruptions of connectivity at an Autonomous System (AS) level due to government censorship or natural disasters. Here we explore another IBR-derived metric which may provide insights into the causes of macroscopic connectivity disruptions. Specifically, we propose a metric indicating packet loss (e.g., because of link congestion) from a specific AS.