A1.3 Network Devices - Panasonic KX-TDA0484 Getting Started

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 below, the card is located as close to the IP network interface as
possible.
Too many hops
Router
Switch
Switch
Hub
A1.3 Network Devices
You must evaluate the network devices that are used in the existing network to see if a VoIP
network can be implemented. Below are the points that should be taken into your evaluation.
Can the firewall pass packets from the VoIP Gateway Card?
If the VoIP network contains a firewall, the firewall must be configured appropriately to allow
VoIP packets, which are listed in the table below, to pass through the network without being
blocked by filtering.
For more information, consult your network administrator.
HTTP *1
RTP/RTCP
H.225.0 Call Signaling
H.245 *2
H.225.0 RAS
*1 For the actual setting values, refer to "2.2.2 H.323 Parameters" in the VoIP Gateway Card
Programming Guide.
Protocol
*2
*2
*2
Better
(PBX located nearest IP network access point)
Router
Switch
Switch
Hub
TCP/UDP
TCP
UDP
TCP
TCP
UDP
A1 VoIP Requirements
Default Port No.
80
5004 to 5011
1720
1712 to 1724
1719
Getting Started 57