Description of sidecar services …
M-Lab Sidecar Services
-    TracerouteCollects network path information for every connection to the M-Lab platform. 
-    Packet HeadersCollects packet headers for all incoming TCP flows and saves each stream of packet captures into a per-stream .pcap file. 
-    TCP_INFOCollects statistics about the TCP connections running on the M-Lab platform using tcp-info.