You are right. We want to open one port in our firewall to allow SAProuter connections (3299 port, for example), establish NAT and so on. So we need to use SNC protocol to secure communications. To increase security, we can try to make IP filter in firewalls or SAProuter table.
Do you know if there is some 3rd party software certified by SAP to allow a direct SNC connections between SAP GUI and SAProuter?
Thanks,
Sergio