A1 VoIP Requirements
Getting Started
51
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.
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.
Protocol
TCP/UDP
Default Port No.
HTTP
*1
TCP
80
RTP/RTCP
*2
UDP
5004 to 5035
H.225.0 Call Signalling
*2
TCP
1720
H.245
*2
TCP
1712 to 1724
H.225.0 RAS
*2
UDP
1719
QSIG Connectionless Tunnelling
*1
TCP
1718
*1
For the actual setting values, refer to "2.2.1 Network Parameters" in the VoIP Gateway Card
Programming Guide.
Router
Switch
Too many hops
Switch
Hub
Router
Switch
Better
(PBX located nearest IP network access point)
Switch
Hub
Summary of Contents for KX-TDA0490
Page 4: ...4 Getting Started ...
Page 20: ...2 2 Cable Connection 20 Getting Started ...
Page 45: ...Getting Started 45 Appendix A Guidance for VoIP Installation ...
Page 55: ...Getting Started 55 Appendix B Alternative Numbering Plan Example ...
Page 63: ...Getting Started 63 Appendix C Initialisation of the VoIP Gateway Card ...
Page 66: ...C1 Initialising the VoIP Gateway Card 66 Getting Started ...
Page 67: ...Getting Started 67 Appendix D Using the KX TDA0490 and KX TDA0480 in One Network ...
Page 69: ...D1 Considerations in Installation Getting Started 69 ...
Page 76: ...1 1 Starting the IP GW16 Maintenance Utility 6 Programming Guide ...
Page 126: ...2 5 Others 56 Programming Guide ...
Page 139: ...Programming Guide 69 Index ...