Applications based on OpenDLV are grouped in UDP multicast sessions belonging to IPv4 address 225.0.0.X, where X is from the within the range [1,254]. All microservices belonging to the same UDP multicast group are able to communicate with each other; thus, two applications running in different UDP multicast sessions do not see each other and are completely separated. The actual UDP multicast session is selected using the commandline parameter --cid=111, where 111 would define the UDP multicast address 188.8.131.52. Microservices exchange data using the message Envelope that contains besides the actual message to send further meta information like sent and received timestamp and the point in time when the contained message was actually sampled. All messages are encoded in Google's Protobuf data format (example) that has been adjusted to preserve forwards and backwards compatibility using libcluon's native implementation of Protobuf.