Exam MS-720 topic 3 question 11 discussion

Actual exam question from Microsoft's MS-720

Question #: 11
Topic #: 3

You have a Microsoft Teams Phone deployment.
You are deploying Direct Routing.
All users have a SIP URI in the format of [email protected]. The Session Border Controller (SBC) is named sbc.voice.contoso.com.
When troubleshooting errors on the SBC, you receive the warning shown in the following exhibit.

What is a possible cause of the issue?

A. The tenant is missing a vanity domain of voice.contoso.com.
B. The firewall blocks outbound traffic on port 443 to Microsoft Teams.
C. The certificate does not match the FQDN of the SBC.
D. Media bypass is disabled on the SBC.

Show Suggested Answer

Suggested Answer: B 🗳️

by Marcin_S at Jan. 22, 2023, 5:23 p.m.

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umair1297

2 years, 4 months ago

on exam 15-02-2023

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TheMCT

2 years, 4 months ago

Selected Answer: B

Correct answer is B: If a device receives a "No SIP Options" message, it means that the options message was not received or that the receiving device was unable to process the message. This can be caused by a variety of issues, such as network congestion, firewall or network security configurations, or issues with the SIP devices themselves.

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[Removed]

2 years, 4 months ago

Selected Answer: C

C is correct

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JOtac

2 years, 4 months ago

The answer is C. TCP port used by Microsoft is 5061. The destination port is configurable, but it is never port 443. So answer B is not correct.

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Marcin_S

2 years, 5 months ago

Selected Answer: B

Having just that single screenshot it is hard to say anything about the certificate. Option B - firewall outbound rule to 443 MS Teams Service - could affect SIP Options messages sent from SBC.

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