Panasonic KX-TDA0480, Getting Started Manual

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5.1 Preventing Problems
Getting Started 37
5.1.3 Priority Control
Some routers permit the configuration of priority control features. This allows the router to be
configured to give higher priority to packets with high priority flags. The priority control feature
should be used when available.
To configure, please refer to Section 4.9.1 Configure Gateway Units (KX-TDA0480) of IP
Gateway Card Installation Manual.
5.1.4 Recovery Delay and Jitter Buffer
When voice signals are packetised and transmitted, individual packet can take different paths
through the network and arrive at the destination at varied timings (Jitter). The IP Gateway
Card supports a secondary Jitter Buffer (max. 1920 ms) in which the packets are accumulated
temporarily for processing to compensate for network congestion problems.
To configure, please refer to 4.9.1 Configure Gateway Units (KX-TDA0480) of IP Gateway
Card Installation Manual.
5.1.5 Internet, Intranet, and Virtual Private Networks (VPN)
Manageable networks (e.g., Intranet, Leased Lines, VPN) provide better quality of service
compared to unmanageable networks such as the Internet.
When implementing a VoIP network, care must be taken when assessing bandwidth
requirements. The IP Gateway Card uses 12 k per port when in use. Serialisation delays to the
WAN are lower when higher bandwidths are used.
When using the Internet/VPN, the ISP plays an important role in reducing the variable delay in
the WAN. A regional or national ISP will usually have better connectivity with the backbone and
will be able to guarantee greater service reliability than a local city ISP. When using VPN
facilities, delays may be introduced due to the additional processing time required for
encryption processing.