snc/data_protection/max is a SAP Parameter attribute which is used to control Limit for data protection of Secure Network Comm. 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 specifies the data transfer protection for
connections that were initiated by the R/3 System, including cases
where for the CPI-C or RFC destination used as the QOP (quality
of protection), the use of the maximum is set in the
SNC options (QoP=9).
The parameter is not an upper limit for incoming or outgoing
connections.
You should only change this parameter is if it absolutely
necessary to do so.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.