The SBC supports optionally dropping a received initial INVITE requests without generating any reply (including a 100 response) based on the following algorithm:
The CLI syntax to suppress the response for non-route invite is shown below:
set addressContext <acName> zone <zoneName> sipTrunkGroup <tgName> signaling suppressNonRouteInviteResponse enabled
Refer to SIP Trunk Group - Signaling - CLI for details.