Causes of Dropped Calls
Question
A user has reported an issue with wireless VoIP phones dropping calls during business hours.
When working late or in the evenings, the user does not experience call drops.
When the network technician investigates the issue, all WAPs have balanced the number of connections evenly and are not dropping off the network.
The network technician connects to the wireless network in the user's office and starts a continuous ping to an external server.
The results show a drastic and varied response time for each packet.
Which of the following is the MOST likely cause of the dropped calls?
A.
No QoS configured on the network B.
Signal-to-noise ratio C.
Interference from the microwave in the breakroom D.
Rogue AP installed in the office.
B.
Explanations
A user has reported an issue with wireless VoIP phones dropping calls during business hours.
When working late or in the evenings, the user does not experience call drops.
When the network technician investigates the issue, all WAPs have balanced the number of connections evenly and are not dropping off the network.
The network technician connects to the wireless network in the user's office and starts a continuous ping to an external server.
The results show a drastic and varied response time for each packet.
Which of the following is the MOST likely cause of the dropped calls?
A.
No QoS configured on the network
B.
Signal-to-noise ratio
C.
Interference from the microwave in the breakroom
D.
Rogue AP installed in the office.
B.
Based on the information provided, the most likely cause of the dropped calls is the Signal-to-noise ratio (SNR).
The fact that the issue only occurs during business hours and not in the evening suggests that there may be interference caused by other devices in use during business hours. Additionally, the varied response time for each packet during the technician's ping test indicates that there may be a problem with the wireless signal quality.
Signal-to-noise ratio is a measure of the strength of the wireless signal compared to the level of background noise present. A low SNR can lead to dropped calls and poor call quality, which is consistent with the symptoms reported by the user.
Other potential causes, such as the lack of Quality of Service (QoS) configuration or the presence of a rogue access point, cannot be ruled out entirely without further investigation. However, based on the information provided, SNR is the most likely cause of the issue.
To address this issue, the technician could try the following solutions:
- Relocate the wireless access point to a less congested area with less interference.
- Increase the power output of the wireless access point to improve signal strength.
- Add additional wireless access points to provide better coverage and reduce interference.
- Replace outdated or malfunctioning wireless equipment with newer, higher-quality devices.
- Configure Quality of Service (QoS) to prioritize VoIP traffic over other network traffic.
- Use a wireless spectrum analyzer to identify and mitigate sources of interference.
