220-1101 Question 451
Single answerHigh latencyA technician is troubleshooting complaints that a cloud-based VoIP softphone becomes choppy and delayed every afternoon on a user's laptop. Web pages still load, but voice calls have a noticeable delay and occasional audio gaps. The user is connected over Wi-Fi in a busy office, and a ping test to the VoIP provider shows highly variable response times with occasional spikes over 300 ms. Which action is the BEST first step to reduce the high latency affecting the calls?
- A
Move the laptop to a less congested wireless channel or band, such as 5 GHz, and retest
- B
Increase the laptop's display resolution so the softphone interface renders more efficiently
- C
Replace the laptop battery because low battery health commonly causes network latency spikes
- D
Disable the Windows firewall to remove packet inspection delays
- E
Change the DNS servers on the laptop to public DNS and retest the call quality
Show answer and explanation
Correct answer: A
Explanation
This question tests recognition of high latency symptoms in a real-world support scenario. VoIP is especially sensitive to latency, jitter, and packet loss. The key clues are that the issue appears during busy periods, occurs over Wi-Fi, and shows variable ping times with high spikes. In A+ Core 1 troubleshooting, a strong first step is to isolate wireless interference or congestion by changing channels, moving to 5 GHz when appropriate, or temporarily testing with a wired connection. Best practices from wireless vendor guidance and general network troubleshooting principles support checking RF congestion, signal quality, and competing traffic before making unrelated system changes. DNS changes may help with slow initial lookups, but they do not fix in-call latency. Disabling security controls or replacing unrelated hardware would not be the best first action.
- A. Correct.
Correct. The scenario points to wireless interference or congestion: the issue occurs during busy office hours, the user is on Wi-Fi, and ping shows variable latency with spikes. Moving to a less congested channel or using the 5 GHz band is a practical first troubleshooting step because it can reduce contention and interference, which commonly affect real-time traffic like VoIP more than basic web browsing.
- B. Incorrect.
Incorrect. Display resolution has no meaningful relationship to network latency. A user might choose this if they confuse application performance with network performance, but choppy audio and high ping times indicate a connectivity issue rather than a graphics-rendering problem.
- C. Incorrect.
Incorrect. Battery health does not normally create intermittent network latency spikes on a laptop in this way. Although aggressive power-saving settings can sometimes affect wireless adapter performance, replacing the battery is not the best first step and does not fit the evidence as well as Wi-Fi congestion does.
- D. Incorrect.
Incorrect. Disabling the firewall is not an appropriate first troubleshooting step and creates a security risk. Host firewalls are not a typical cause of afternoon-only latency spikes on VoIP calls, especially when ping results already suggest variable network conditions on the wireless connection.
- E. Incorrect.
Incorrect. DNS affects name resolution, primarily when initially locating services, not ongoing voice packet latency during an active call. Someone might pick this because slow internet is often blamed on DNS, but once the session is established, DNS does not normally cause audio delay or jitter.