Exam 300-820 topic 1 question 133 discussion

Actual exam question from Cisco's 300-820

Question #: 133
Topic #: 1

Cisco Collaboration deployment has video endpoints that can do B2B calls over the internet, but they also can make audio calls through a gateway. This ability means that someone from the internet can make fraud calls through the system. Which action must an engineer take to set up the search rules for calls that are being headed to the PSTN gateway?

A. Ensure that only requests that are authenticated are allowed to make a PSTN call.
B. Avoid using any wild card in the source settings in the search rules.
C. Add registered devices only in the search rule for the PSTN gateway.
D. Add registered devices only in the zone for the PSTN gateway.

Show Suggested Answer

Suggested Answer: B 🗳️

by Ol_Mykhailiuk at Dec. 8, 2022, 2:36 p.m.

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Collabinski

1 year ago

Selected Answer: B

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/expressway/admin_guide/X14-0/exwy_b_cisco-expressway-administrator-guide/exwy_m_dial-plan-and-call-processing.html

upvoted 3 times

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Collabinski

1 year ago

Selected Answer: B

Before You Begin -You need Cisco Expressway version X12.5.7 or later. -You should have knowledge of the North American Numbering Plan (NANP). -From X12.5.7, the usual requirement to have at least one RMS license installed before a call can be placed does not apply to direct 911 calls. -To minimize toll fraud risks, avoid using the "Any" wild card for the Source setting. -The PSTN gateway also needs to be configured to route 911 calls without a prefix. -For deployments that are geographically spread with the gateway in a different location from the endpoints, keep in mind the practical routing requirements for 911 calls and the possibility that callers may be connected to an emergency agent in a different place from their own location.

upvoted 2 times

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Collabinski

1 year ago

Correction. Meant to select answer B

upvoted 1 times

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Collabinski

1 year ago

Selected Answer: C

When Does Kari's Law Apply to Expressway? Kari’s Law deals with audio calls. This law applies to Expressway deployments in the United States in cases where all of the following conditions apply: -Expressway is managing the call control and the endpoint making the emergency call is directly registered to the Expressway-C. -A gateway is configured with Expressway that enables PSTN calling. -The PSTN calling capabilities for your deployment include 911 emergency calls. -The endpoint involved is capable of dialing a PSTN number and making a basic audio call.

upvoted 1 times

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Ol_Mykhailiuk

1 year, 1 month ago

Selected Answer: A

In my opinion, option A is the most suitable. Dial Plan Protection and Toll Fraud Mitigation: https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab11/collab11/gateways.html

upvoted 3 times

Collabinski

1 year ago

That is a valid action in CUCM and you can set the Expressway to process calls as "Treat As Authenticated". The question asked which action with the Search Rule to take for toll fraud, which Cisco recommends against using a source of "Any" in the search rule to prevent toll fraud.

upvoted 2 times

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