Avoid One-Way Audio Configuration

A.

One-Way Audio During a Connected Call Use the following list to identify possible causes for the problem: " Check the access point to see that the transmit power setting matches the transmit power setting on the phone.

One-way audio is common when the access point power setting is greater (100mW) than that of the phone (20mW)

Cisco Unified Wireless IP Phone 7925G Firmware supports dynamic transmit power control (DTPC)

The phone uses the transmit power that the access point advertises upon association.

Note With DTCP, if Client Transmit Power is set in the access point, the phone automatically uses the same client power setting.

If the access point is set for the maximum setting (Max), the access point uses the Transmit Power setting on the phone.

" Check that the access point is enabled for ARP caching.

When the Cisco Unified Wireless IP Phone 7925G is in power save mode or scanning, the access point can respond to the wireless IP phone only when ARP caching is enabled.

" Check your gateway and IP routing for voice problems.

" Check if a firewall or NAT is in the path of the RTP packets.

If so, you can use Cisco IOS and PIXNAT to modify the connections so that two-way audio is possible.

" Check that the Data Rate setting for the phone and the access point are the same.

These settings should match or the phone should be set for Auto.

" Check the phone hardware to be sure the speaker is functioning properly.

" Check the volume settings in the Phone Settings menu.

http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/7925g/7_0/english/administration/guide/7925trb.html#wp1106778

To avoid one-way audio on a Cisco Unified 7925G Wireless IP Phone operating on the 5 GHz band and transmitting at a power level of 40 mW, you need to adjust the controller's maximum power level assignment and the Dynamic Channel Assignment (DCA) settings.

Option A, which recommends setting the maximum power level assignment to 16 dBm, is not the correct answer. This is because 16 dBm is a low power level, and it may not provide enough coverage and signal strength for the phone to communicate effectively with the wireless network. Setting the maximum power level too low could result in weak signal strength, signal interference, and even dropped calls.

Option B, which recommends setting the maximum power level assignment to 26 dBm, is the correct answer. This is because 26 dBm is a higher power level, and it will provide the phone with sufficient signal strength and coverage to communicate effectively with the wireless network. However, it is important to note that increasing the power level beyond the regulatory limit may result in interference with other devices, which may affect the overall network performance.

Option C, which suggests enabling only UNII-I channels in DCA, is not a valid option. This is because UNII-I channels are not typically used for voice traffic and may not provide the necessary throughput and coverage for the phone to communicate effectively with the wireless network.

Option D, which suggests enabling only UNII-II channels in DCA, is also not a valid option. This is because UNII-II channels are typically used for data traffic, and they may not provide the necessary QoS and coverage for voice traffic.

In summary, to avoid one-way audio on a Cisco Unified 7925G Wireless IP Phone, you should set the maximum power level assignment to 26 dBm on the controller and configure DCA to enable UNII-II and UNII-III channels to ensure optimal coverage, throughput, and QoS for voice traffic.