A VoWLAN has been deployed at a customer site. and users report that audio is choppy in some areas The exhibit captures a voice exchange between one phone that is associated to the AP at the end of the corridor (172.31 255 101) and another phone that is positioned in a conference room nearby. Which action enhances the voice application quality of experience?
Refer to the exhibit.
A. Change the basic rate configuration on the WLC to include 54 Mbps.
B. Change the WLAN QoS profile to platinum.
C. Decrease the AP power level.
D. Disable higher data rates on the controller.
B.
From the information in the picture, we can see the QoS set to DATA. So to improve the quality of the voice we must change it to PLATINUM (Voice).
I can’t see the information about data rate, and power from the picture.
WRONG. learn this: https://mrncciew.com/2014/10/03/cwap-mac-header-qos-control/ and get used to wireshark.
QoS control field is not shown on the picture.
Instead, you can find data rates on the picture.
802.11g and 802.11a phone clients may be capable of rates up to 54 Mbps. Current chip sets support 54 Mbps, but transmit power capabilities do differ. Cisco highly recommends that all links between phone clients and APs be established using matching transmit power levels.
Cisco highly recommends that the maximum configured transmit power on the access be no higher than the client phone devices hardware supports. A phone with a slightly lower transmit power than the AP is better than the AP using less power than the phone, but having matching transmit powers lessens the likelihood of one-way audio
Best guess : D i.e. Disable higher data rates on the controller.
The package shown has QoS Data 0x28 -> EF5
Looks like that Platinum has already been implemented.
So i suppose A is correct
D is correct, I remember this troubleshooting scenario from one of the Cisco training videos. Client is sending frames at higher data rates, but AP doesnt hear well the frames from client. AP recognizes only frame sent by 12mbit data rate and sends ACK to this frame. But client keeps to try to communicate at higher data rates, and has to downshift to 12mbits every time. And this rate downshifting by client takes too much time.
So disabling high data rates would help in this case.
Absolutely correct.
In my opinion the correct answer is B: disabling higher data rates the commmunication between the ap and the phones becomes slower. Enabling QoS voice packets will be prioritized.