Introduction

Within the LLUDP protocol, there is a message type called GenericMessage. This has the following structure (taken from a viewer's app_settings/message_template.msg file).

 GenericMessage  Low 261 NotTrusted Zerocoded
 {
   AgentData     Single
   {   AgentID     LLUUID    }    
   { SessionID LLUUID    }    
   { TransactionID LLUUID  }
 }
 {
   MethodData  Single
   { Method    Variable 1 }
   { Invoice   LLUUID  }
 }
 {
   ParamList   Variable
   { Parameter Variable 1 }
 }

Linden Lab uses this message for some miscellaneous functionality. However, because we can switch messages on the Method parameter, we can also use GenericMessage as a carrier of arbitrary UDP data between the client/viewer and the simulator, as GenericMessages can flow both ways.

Example

Typically, we would create an OpenSimulator region module to subscribe to the GenericMessages with certain Method names.