Configuring Support of SNC Components 
The parameter snc/enable specifies whether the gateway is to support SNC (see SAP Gateway and SNC Interface). If this parameter is deactivated (snc/enable = 0, default value), no SNC connections are accepted.
If this parameter is activated (snc/enable = 1), only SNC connections are accepted.
The gateway checks whether connections to non-SNC programs are permitted. If the parameter snc/permit_insecure_start = 1, connections to non-SNC programs are permitted.
Prerequisites
The gateway specifies its own path name for the SNC library in the command line parameter. If the program you want to start is running on the same host, the environment variable SNC_LIB does not need to be set. If it isn’t, the environment variable SNC_LIB does need to be set in the relevant login shell or in the user environment. This variable specifies the respective shared library of the security product that is being used.
Procedure
Define the relevant parameters and environment variables.
The SNC parameters are described in Parameterization of the SAPGateway under SNC Parameters.
Using SAProuter to Secure the Connection Between Two Gateways
As an alternative to SNC support, you can also secure communication between SAP gateways of different SAP systems by using SAP routers (gateway 1 – SAProuter1 - SAProuter2 - gateway2). The SAP routers take on the SNC encryption and SNC encoding tasks. An additional system security with SNC (as described above) is then not necessary.