300-370 · Question #116
An engineer is troubleshooting reports from a Cisco 7925 user that is experiencing consistent gaps in audio when roaming from one area of the facility to another. Packet analysis shows that the phone
The correct answer is C. Use coverage hole detection to allow the access points to compensate for the poor roaming.. To fix a Cisco 7925 phone flapping between APs due to poor SNR during roaming, enabling Coverage Hole Detection on the WLC allows access points to dynamically compensate for weak signal areas.
Question
An engineer is troubleshooting reports from a Cisco 7925 user that is experiencing consistent gaps in audio when roaming from one area of the facility to another. Packet analysis shows that the phone is flapping between two access points due to poor SNR. Which action fixes this issue?
Options
- AAdd access points to the areas that have a noise floor below -90 dBm.
- BAdjust the roaming threshold of the WLC to -67 dBm for improved access point performance.
- CUse coverage hole detection to allow the access points to compensate for the poor roaming.
- DRedesign the area for sufficient overlap with access points running at reduced power levels.
How the community answered
(47 responses)- A13% (6)
- B4% (2)
- C57% (27)
- D26% (12)
Why each option
To fix a Cisco 7925 phone flapping between APs due to poor SNR during roaming, enabling Coverage Hole Detection on the WLC allows access points to dynamically compensate for weak signal areas.
Adding access points to areas with good noise floors (-90 dBm is low noise) does not directly address the issue of poor SNR causing flapping between existing access points.
Adjusting the roaming threshold to -67 dBm might cause clients to hold onto weaker signals longer, potentially worsening the poor SNR and increasing the likelihood of disconnections or poor performance.
Cisco's Coverage Hole Detection (CHD) feature allows a Wireless LAN Controller (WLC) to identify areas where client devices experience poor signal strength. Once detected, the WLC can instruct nearby access points to increase their transmit power or adjust data rates, thereby improving coverage, stabilizing connections, and reducing client flapping during roaming.
Redesigning the area is a more drastic and time-consuming solution; reducing power levels without careful planning could exacerbate coverage issues if not properly implemented for optimized overlap.
Concept tested: Cisco WLC client roaming optimization features
Source: https://www.cisco.com/c/en/us/td/docs/wireless/controller/7-0/configuration/guide/c70sol/c70chd.html
Topics
Community Discussion
No community discussion yet for this question.