icm/IIOP/max_request_size_KB is a SAP Parameter attribute which is used to control Maximum size of IIOP-request which is accepted by ICM information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
This parameter protects the application server from a Denial of Service
attack with large requests. If the parameter value is not equal to -1,
the Internet Communication Manager already checks whether the length ()
of the request exceeds the specified value of the parameter. If it does,
the request is not passed to the application server, and an error
message is sent to the caller ().
See SAP Parameter Documentation for full SAP documentation for this profile parameter.