Vijay,
Thanks for your respond. But I already read both links. It needs the SAP NetWeaver AS JAVA server to run on it. My system doesn't have the SAP NetWeaver AS JAVA. Currently, my system runs in SAP NetWeaver AS ABAP Platform. As far as I know, AS ABAP only used Kerberos to use SSO, which only runs in same network as the server, not in the internet-facing client. And it needs mapping between windows login users and SAP Logon. Please, correct me if I'm wrong.