A1.4 Qos (Quality Of Service) - Panasonic KX-TDA0490 Getting Started

*2 For the actual setting values, refer to "2.2.2 H.323 Parameters" in the VoIP Gateway Card
Programming Guide.
Are layer 2 or higher switches used?
Use of repeater hubs can increase the network load, and therefore will result in degradation in speech
quality.
To ensure high speech quality, use only layer 2 or higher switches.
Note
Also note that the port of the switch that connects to the card should be set to operate under
"Auto Negotiation" mode. This will help assure error-free communication between the card and
the switch.
Are Category 5 (CAT5) cables used?
When connecting network devices, make sure to use CAT5 cables. If other types of cables are used,
communications may not be carried out normally.
A1.4 QoS (Quality of Service)
Some routers permit the configuration of priority control features. This allows the router to give higher
priority to voice packets and lower the rate of loss and delays during transmissions, hence improving
speech quality. It is strongly recommended that you use this feature, especially in networks where
traffic is heavy.
Typically, a router identifies what packets to pass in priority by checking the value in the ToS field of
the header of IP packets. The VoIP Gateway Card has the ability to set the ToS field of outgoing voice
packets (see "2.2.3 Voice Communication Parameters" in the VoIP Gateway Card Programming
Guide). When the card is appropriately configured, the router can give voice packets from the card
higher priority.
Consult your network administrator when setting the ToS field, as the setting value must conform to
the router's specifications.
Note
Some switches also permit the configuration of priority control features. For more information,
consult your network administrator.
A1 VoIP Requirements
Getting Started 53