300-820 · Question #131
An engineer learns from an end user that calls from outside the company are not being received. Calls are being made to other businesses outside of the company on video using URL addresses. The…
The correct answer is B. On the Expressway-E, run diagnostic logging under maintenance to see if any requests reach the. Because external calls are not being received, the Expressway-E is the first point of entry for inbound calls from the internet and is therefore the best starting point for diagnostics. Running diagnostic logging on the Expressway-E under Maintenance > Diagnostics will capture…
Question
An engineer learns from an end user that calls from outside the company are not being received. Calls are being made to other businesses outside of the company on video using URL addresses. The change management log shows no changes in the configuration of the collaboration solutions. The engineer examines the endpoint, which seems to be registered to the Cisco UCM, and the SIP trunk between the Cisco UCM and sees that the Expressway is also up. In addition, the traversal link shows no errors between the Expressways. Which action must the engineer take to troubleshoot this issue?
Options
- AOn the Cisco UCM, run the Real-Time Monitoring Tool to see if any incoming calls fail.
- BOn the Expressway-E, run diagnostic logging under maintenance to see if any requests reach the
- COn the Expressway-E, check the NTP settings to ensure that TLS will be able to terminate. If the
- DOn the Expressway-C, run a network log under administrative tools to see if any requests reach
How the community answered
(20 responses)- A10% (2)
- B80% (16)
- C5% (1)
- D5% (1)
Explanation
Because external calls are not being received, the Expressway-E is the first point of entry for inbound calls from the internet and is therefore the best starting point for diagnostics. Running diagnostic logging on the Expressway-E under Maintenance > Diagnostics will capture whether inbound SIP INVITE requests are reaching the edge device at all. If no requests appear, the problem is upstream (DNS, firewall, or carrier). If requests arrive but fail, the logs will show the specific SIP error. RTMT on CUCM is useful only after confirming the call has passed through the Expressways. Checking NTP or running logs on Expressway-C are secondary steps after confirming whether traffic is reaching the edge.
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