A3 Optimising Performance; A3.1 Voice Volume; A3.2 Transmission Delays - Panasonic KX-TDA0480 Getting Started

A3 Optimising Performance
Although the features of the VoIP Gateway Card go a long way toward assuring clear voice
communications and error free fax transmission over digital data networks, some network
conditions can cause performance degradations.
Common causes include:
• Voice PAD settings not correctly configured.
• Many collisions among packets within the Local Area Network (LAN).
• Number of hops packets go through is too large.
• High traffic conditions are prevalent on the network.
• Routing through a firewall.
• Wide Area Network (WAN) transmission delays.
• Internet Service Provider (ISP) has inadequate service characteristics.
The methods used to prevent problems and optimise performance depend on the type and
configuration of the network equipment in use. Below are some suggestions that may prove
useful.
A3.1 Voice Volume
In some applications, voice volume may be either too low or too high. The gain control feature
operates on both the incoming and outgoing sides and is referred to as the PAD control. The
VoIP Gateway Card is able to optimise the gain or loss level of the voice signals.
In most cases, it should not be necessary to modify the default PAD In (PAD value of the voice
signals coming in to the unit)/PAD Out (PAD value of the voice signals going out from the unit)
settings. Indications that some adjustment is required are:
Voice level too low: Increase gain by decreasing PAD level.
Voice loud/distorted: Decrease gain by increasing PAD level.
Excessive background noise: Decrease gain by increasing PAD level.
To configure, refer to "4.9.1 Configure Gateway Units (KX-TDA0480)" in the VoIP Gateway
Card Installation Manual.
A3.2 Transmission Delays
Transmission delays can cause pauses and loss in voice communications and may result in
delays and loss of fax transmissions. These conditions typically arise when there are high
traffic loads (congestion) on the LAN and/or WAN. In the case of the LAN, the network design
affects performance. In the case of the WAN, the local router, the link to the ISP (i.e. ISDN, FR,
F/T1, and T1), and the Internet Service Provider (ISP) facilities also affect performance.
Transmission delays are caused by excessive packet collisions. The probability that this
condition will affect the VoIP Gateway Card performance can be minimised by taking steps to

A3 Optimising Performance

Getting Started 45