Polycom 3725-32870-002 - Manual (Page 40)

Chapter 4 – Administrator Configuration
4-10
Parameter Description
System Prefix/E164 Sets the E.164 number for the system.
System H.323 Alias Sets the H.323 alias for the system.
3 Click Update and a dialog box will pop up, in which you should confirm
to restart the system to apply the setting.
QoS
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:
1 Click System Config>Signaling Setting>QoS in the menu bar at the top
of the page.
2 On the QoS page, configure the following parameters:
Table 4-9 QoS Parameters Description
Parameter Description
Enable QoS
Select this option to enable configuration of the QoS
settings. When un-checked, the system uses the default
QoS settings.
Type
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 fields. 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. If this option
is selected, enter values in the Audio and Video fields, in
the value range of 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.