Qos - Polycom RSS 4000 User Manual

Chapter 4 - Administrator Configuration

QoS

•
•
•
1
2
4-20
Quality of Service (QoS) is very important in transmission of
high-bandwidth audio and video data. You can use QoS to test and
guarantee the following parameters:
Average packet delay
Delay variation (jitter)
Error rate
To specify QoS parameters:
Click System Config>Signaling Setting>QoS in the menu bar at the top
of the page.
On the QoS page, configure the following parameters:
Table 4-25 QoS Parameters Description
Parameter
Enable QoS
Type
Audio / Video
Description
Select this option to enable configuration of the QoS
settings. When un-checked, the system uses the default
QoS settings.
DiffServ and Precedence are two methods for encoding
packet priority. The priority set here for audio and video
packets should match the priority set in the network
routers.

Differv: Select when the network router uses Differv for
priority encoding. If this option is selected, enter values
in the Audio and Video fileds. The value range is 0-63.
Note: If you select DiffServ but your router does not
support this standard, IP packets queue on the same
communication links with data packets. This
non-prioritized queueing greatly increases the latency and
jitters in their delivery and can negatively impact
performance.

Precedence: Select this option when the network router
uses Precedence for priority encoding, or when you are
not sure which method is used by the router.
Precedence should be matched with None in the Tos
field. The value range is 0-5. If this option is selected,
enter values in the Audio and Video fields. The value
range is 0-5.
Note: Precedence is the default mode as it is capable of
providing priority services to all types of routers and is
currently the most common mechanism.
Specify the priority for audio and video IP packets.
The recommended priority is 4 for audio and video to
ensure that the packet delay for both is the same, that
audio and video packets are synchronized, and to ensure
lip and audio synchronization (lip sync).
Polycom, Inc.