Panasonic Kx Tda5480 Getting Started Manual

Getting Started 51
Appendix A
Guidance for VoIP Installation 

A1 VoIP Requirements
52 Getting Started
A1 VoIP Requirements
A1.1 Bandwidth Assessment
To establish a VoIP network, you must ensure that the network has enough bandwidth to 
support VoIP communications. Inform your network administrator of the required bandwidth, 
and make sure that the network can support VoIP communications even under conditions of 
maximum network traffic.
Bandwidth Calculation
Provided below is the formula to find out the amount of bandwidth required for VoIP 
communications:...

A1 VoIP Requirements
Getting Started 53
Required Bandwidth for Fax Communication
Via LAN
Via WAN (PPP: Point-to-Point Protocol)
Example
Consider the following case as an example:
Communication: via LAN
No. of Fax Machines: 1
Required Bandwidth for Fax Communication: 75.6 kbps
Required Bandwidth for Voice Communication: 23.5 kbps
In this case, the required bandwidth will be as follows:
Therefore, inform your network administrator and make sure that the network can support a 
bandwidth of 146.1 kbps...

A1 VoIP Requirements
54 Getting Started
Is it possible to have static IP addressing?
Because the maintenance of the VoIP Gateway Card is carried out from a personal computer 
(PC) through an IP network, the card must be assigned a static IP address.
Static IP addressing must be made possible even when the DHCP feature is used. For more 
details, refer to 2.2.1 Network Parameters in the VoIP Gateway Card Programming Guide.
Is network address translation (NAT/NAPT) disabled?
In a network where address...

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Getting Started 55
Does only a single router provide access to the IP network?
In a dual network, two routers provide access to the IP network as shown in the diagram below. 
However, the VoIP Gateway Card cannot take the advantage of having two routers as access 
points to the IP network.
For example, if router A, whose IP address is assigned as the default gateway IP address of 
the card, fails, VoIP communications are no longer possible; the card is not able to switch its 
default...

A1 VoIP Requirements
56 Getting Started
Is there only a single IP network between two ends of a call?
A huge degradation in speech quality will be produced when calls are made through multiple 
IP networks as shown below; therefore, it is recommended that you avoid establishing a VoIP 
network in this fashion.
IP Network 1IP Network 2
PSTN
IP Network 1IP Network 2 

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Getting Started 57
Is the card located appropriately?
Transmission delays can cause pauses and loss in VoIP communications. The more network 
devices (e.g., routers and switches) there are between the communicating cards, the larger the 
transmission delays, because a certain amount of delay is inevitable when packets go through 
each network device (hop).
One preventative measure is to install the card so that the number of transmission hops is kept 
to a minimum. In the diagram...

A1 VoIP Requirements
58 Getting Started
Are layer 2 or higher switches used?
Use of repeater hubs can increase the network load, and therefore may result in degradation 
in speech quality.
To ensure the performance, it is strongly recommended that you use layer 2 or higher switches.
Are category 5 (CAT 5) cables used?
When connecting network devices, make sure to use CAT 5 cables. If other types of cables are 
used, communications may not be carried out normally.
A1.4 QoS (Quality of Service)
Some...

A2 VoIP Requirements Checklist
Getting Started 59
A2 VoIP Requirements Checklist
Use the following checklists to see if you can implement a VoIP network. The answers identified 
in underlined bold-face letters
 are the required answers for the corresponding questions.
Bandwidth Assessment
Network Configuration
No. Question Answer Memo Ref.
1Does the network have enough 
bandwidth to support VoIP 
communications?
Make sure that there is more bandwidth 
available for VoIP communications than the 
amount...

A2 VoIP Requirements Checklist
60 Getting Started
Network Devices
QoS (Quality of Service)
No. Question Answer Memo Ref.
3-aCan the firewall pass packets from the 
VoIP Gateway Card?
When a firewall is used, make sure to 
configure the firewall appropriately to allow 
VoIP packets to pass through the network 
without being blocked by filtering. Ye s
 NoModel of the firewall:
p. 57
3-bAre layer 2 or higher switches used?
Do not use repeater hubs as they can 
increase the network load. Ye s
 NoModel of the...