How can you configure VCS Expressway to make sure an external caller cannot reach a specific internal address?
A. VCS Expressway only forwards calls to Cisco Unified Communications Manager who block calls.
B. You make a transform on the VCS Expressway to direct the call to VCS Control, which can block the call.
C. You add a search rule to block any call to the specific URI on the internal VCS Control.
D. You add the specific URI in the firewall section of the VCS Expressway and block it.
E. You block the call with a search rule that has a high priority in the VCS Expressway.
Answer: E
Restricting Access to ISDN Gateways (Optional)
We recommend that you restrict unauthorized access to any ISDN gateway resources (also known as toll-fraud
prevention). Some methods to achieve this are described here.
Expressway-E
Two search rules are created on the Expressway-E:
■ Both rules have a pattern string that matches calls directed at the ISDN gateway. (In this example calls
prefixed with a 9.)
■ The first rule has a Source of All zones. This allows calls from registered endpoints and neighbor zones to pass
through to the traversal zone.
■ The second rule is similar to the first rule but has a Source of All. So it includes nonregistered endpoints
(which are excluded from the previous rule). They can be stopped by defining the Replace string as “do-notroute-this-call.”
■ Both rules stop any further search rules from being looked at (On successful match = Stop).
Priority: Enter 40
(these rules must be the highest priority in the search rule configuration)
https://www.cisco.com/c/dam/en/us/td/docs/voice_ip_comm/expressway/config_guide/X8-10/Cisco-Expressway-Basic-Configuration-Deployment-Guide-X8-10.pdf
I think the answer should be related to Call policy rules.