A1.3 Network Devices - Panasonic KX-TDA0490 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
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 Signalling
H.245 *2
H.225.0 RAS
QSIG Connectionless Tunnelling
*1 For the actual setting values, refer to "2.2.1 Network Parameters" in the VoIP Gateway Card
Programming Guide.
Router
Switch
Switch
Hub
Protocol
*2
*2
*2
(PBX located nearest IP network access point)
Router
Switch
Switch
Hub
TCP/UDP
TCP
UDP
TCP
TCP
UDP
*1 TCP
A1 VoIP Requirements
Better
Default Port No.
80
5004 to 5035
1720
1712 to 1724
1719
1718
Getting Started 51