Voice Packet Prioritization; Limitations - Motorola MC55 User Manual

If the user is using a Bluetooth headset, tapping the VQM icon un-pairs the Bluetooth headset from the device
causing the audio to be routed to the default mode. In VQM 2.5, there is no way to go back to the Bluetooth
headset using the VQM icon if it is un-paired The only way to reconnect the Bluetooth headset to the device is by
using the BTExplorer application.
If the user taps the VQM icon while not on a call there is not change to the audio mode.
Tap and hold the VQM icon in the title bar to display a notification dialog box that contains:
• AEC: The Acoustic Echo Canceller status
• DSCP Marked Packets: The number of outbound voice packets that have been recognized and marked as
high priority by VQM.
• VQM Version: The VQM version number.
VQM Audio Control Dialog Box
Figure B-2

Voice Packet Prioritization

IP soft phones transmit voice packets in the same manner as any other application that sends data over the
network. On a network with different types of traffic, voice packets are given the same priority as any other traffic,
and therefore may be subject to delays.
WiFi Multi-media (WMM) is a solution to this problem. WMM is a specification that supports prioritizing traffic, and
"higher-priority" packets can be given preferential treatment.
To make use of WMM, the devices that generate traffic must mark their packets as high or normal priority in a field
in the IP packet called Differentiated Services Code-Point (DSCP). The wireless infrastructure, which must be
configured to support WMM, gives a higher priority to packets that have been marked as high priority through
DSCP marking by the devices that generate traffic.
VQM detects if there is an ongoing Voice over WiFi (VoWiFi) call, and if so, marks outgoing voice packets (Only
outgoing voice packets can be marked. The incoming voice packets have already been through the network, so it
makes no sense to mark them.) as high-priority using DSCP. This enables WMM-compatible wireless infrastructure
to treat the voice packets preferentially. This results in fewer delays for voice packets, which in turn improves the
call quality.

Limitations

There is no VPN support in VQM.
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Using the Interfaces B - 3