Panasonic KX-NCP0158 Quick Installation Manual page 67

Are the network devices located appropriately for effective VoIP communications?
Transmission delays can cause pauses and loss in VoIP communications. The more network devices (e.g.,
routers and switching hubs) there are between the PBX and IP-CSs or the IP network interface, the longer the
transmission delays. This is because a certain amount of delay is inevitable when packets go through each
network device.
To prevent unnecessary delays, it is recommended to connect the PBX as close to the IP-CSs and the IP
network interface as possible so that the number of the network devices is kept to a minimum.
Router
Switching
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 evaluated.
Can the firewall pass packets appropriately?
If the VoIP network contains a firewall, the firewall must be configured appropriately to allow VoIP packets,
listed in the table below, to pass through the network without being blocked by filtering.
For more information, consult your network administrator.
[IP Packets from IPCMPR/IPCEMPR Card and IP-CSs]
Protocol
RTP (IP-CS)
Maintenance (IPCMPR/
IPCEMPR)
Maintenance (IP-CS)
MGCP (IPCMPR/
IPCEMPR)
MGCP (IP-CS)
DHCP (IPCMPR/
IPCEMPR)
DHCP (IP-CS)
IP Network
Switching
Hub
Hub
Description
Real-time Transport Protocol.
Used for voice data transmission.
Panasonic proprietary protocol.
Used for communication parameter
negotiation with the PBX, download of
country/area data, confirmation of
connection with the PBX, and
notification of error messages and
statistical information to the PBX.
Media Gateway Control Protocol.
Used for call control command data and
LCD/LED data transmission.
Dynamic Host Configuration Protocol.
Used for receiving an IP address from a
DHCP server.
Router
Switching
Hub
UDP
UDP
UDP
UDP
UDP
UDP
UDP
C Guidance for VoIP Installation
TCP/UDP Default Port No.
12000 to 12255
39300
9301
32727
2427
67
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Quick Installation Guide 67