Implementing Cisco Advanced Call Control and Mobility Services (CLACCM) — Question 201

Cisco SIP IP telephony is implemented on two floors of your company. Afterward, users report intermittent voice issues in calls established between floors. All calls are established, and sometimes they work well, but sometimes there is one-way audio or no audio. You determine that there is a firewall between the floors, and the administrator reports that it is allowing SIP signaling and UDP ports from 20000 to 22000 bidirectionally. What are two possible solutions? (Choose two.)

Answer options

• A. Go to the SIP profile assigned to these IP phones in Cisco Unified CM and change the range of media ports to 16384-32767
• B. Ask the firewall administrator to change the ports to TCP.
• C. Ask the firewall administrator to change the range of UDP ports to 16384-32767.
• D. Go to the SIP profile assigned to these IP phones in Cisco Unified CM and change the range of media ports to 20000-22000.
• E. Go to System Parameters in Cisco Unified Communications Manager and change the range of media ports to 20000-22000.

Correct answer: C, D

Explanation

The correct solutions involve adjusting the UDP port range to 16384-32767 and ensuring the SIP profile media port range is set correctly. Changing to TCP (option B) would not resolve the issues since SIP typically uses UDP for media transport. Keeping the media ports within the original 20000-22000 range (option E) would not address the problems, as those ports may already be insufficient for reliable audio transport.