Obviously you need to fill in the SIP URI of the Application Server. You can use of course parameters, ports, etc.

Then you need to specify what should the S-CSCF do if this Application Server fails to respond to messages. You can indicate that you want the sessions to be terminated or continued based on how critical is your Application Server in your system.

Because almost any SIP server/proxy/user-agent can act as an Application Servers and they can be trusted, semi-trusted or completely untrusted, you need to also configure what is that Application Server allowed to do when communicating directly with the HSS, on the Sh interface.

Only because you have configured an AS in the HSS, it does not mean that signaling will be redirected towards it. You need to:
- attach this Application Server to one or more Initial Filter Criteria (which contain the message matching rules in the Trigger Points),
- then add the Initial Filter Criteria to a Service Profile,
- then make sure that your users have the right Service Profiles attached.