An attribute in a MR (message-routing) diameter router profile that causes Diameter iRule events to be processed in the scope of the executing message, rather than one by one in the scope of the connection. If true, each message has its own Tcl execution context and local variables, and may execute iRules concurrently with other messages. Otherwise all messages on a connection flow share a single execution context and share their local variables, so must queue to execute one by one. This is false by default (the legacy mode). Before setting this to true, some pre-existing iRules might need to be adjusted to avoid sharing local variables.