Are the IP-EXT16 card and IP-PTs located appropriately?
Transmission delays can cause pauses and loss in VoIP communications. The more routers there are
between the IP-EXT16 card and IP-PTs, the longer the transmission delays, because a certain amount of
delay is inevitable when packets pass through each router.
Additionally, the more switching hubs between the card and IP-PTs, the longer the transmission delays,
because the switching hubs must also handle the network traffics generated by other terminal devices (e.g.,
PCs) connected to them.
To prevent unnecessary delays, it is recommended to connect the card and IP-PTs so that there are as few
network devices (e.g., routers, switching hubs) between them as possible.
Router
2.1.3
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 evaluated.
Can the firewall pass packets from IP-PTs?
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.
Protocol
RTP (IP-EXT16)
RTP (IP-PT)
Maintenance (IP-EXT16)
Maintenance (IP-PT)
MGCP (IP-EXT16)
MGCP (IP-PT)
IP Network
Switching
Hub
Switching
Hub
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.
Router
Switching
Hub
Description
Information about IP Proprietary Telephones
2.1 VoIP Requirements
TCP/UDP
Default Port No.
UDP
8000 to 8063
UDP
8000 to 8063
UDP
9300
UDP
9301
UDP
2727
UDP
2427
15