A wireless engineer is performing a post verification of a wireless network. Which two metrics does the engineer verify to ensure that the wireless network can support voice services? (Choose two.)
A. The coverage area must have a noise floor that does not exceed -87 dBm.
B. The client device must have at least an -67 dBm RSSI.
C. The rate of retransmitted packets must be 15 percent or below.
D. The rate of retransmitted packets must be 20 percent or below.
E. The client device must have at least an -65 dBm RSSI.
https://www.cisco.com/c/en/us/td/docs/wireless/technology/vowlan/troubleshooting/vowlan_troubleshoot/8_Site_Survey_RF_Design_Valid.html
RF Design Validation
1. The optimal VoWLAN Cell Edge recommendation is -67 dBm.
2. An optimal VoWLAN deployment will require at least a 20 percent cell overlap for 2.4 GHz and 15-20 percent for 5 GHz for access points that reside on different channels.
3. Over all Channel Utilization should be less than 50 percent.
4. The Noise floor should not exceed -92 dBm, which facilitates a Signal to Noise Ratio of 25 dB.
5. Retransmissions should be kept under 20 percent.
6. Packet Loss should remain under 1 percent and jitter should be kept to less than 100 ms.
Retransmission rate for voice should be kept below 20 percent