Implementing and Operating Cisco Collaboration Core Technologies (CLCOR) — Question 192
How does an administrator ensure compliance with ITU-T G.114 latency requirements when deploying voice and video applications over routes that include a geostationary satellite?
Answer options
- A. For voice and video applications over satellite, Cisco recommends using WAN optimization compression, which will save space or time of the transmission. The latency will then be below the recommended latency threshold for voice.
- B. Using G.729 voice codec Instead of G.711 voice codec will reduce the packet size and the latency to stay within the recommended threshold.
- C. The satellite is 35,786 km (22,236 miles) above sea level (from the equator), so an engineer will not get below 150 ms latency in one direction and will need to manage the expectation of the user.
- D. The application will work because it will be below the recommenced latency requirement If an engineer uses compressed headers to speed up the voice packets.
Correct answer: C
Explanation
The correct answer is C because the physical distance of the satellite limits latency to above 150 ms in one direction, making compliance with ITU-T G.114 impossible. Options A and B suggest methods to reduce latency but do not address the inherent limitations of satellite communication. Option D incorrectly assumes that header compression alone can bring the latency within acceptable limits.