Panasonic Hybrid IP-PBX Manual page 13

Is it possible to have static IP addressing?
IP-PTs on the network must always communicate with each other through the IP-EXT16 card, not directly.
Therefore, the card must be assigned a static IP address, which must be programmed to each IP-PT on the
network.
Note
When a DHCP server (which automates IP addressing of the IP-PTs on the network) is not used, static
IP addressing must also be enabled for all IP-PTs.
Does only a single router provide IP-PT access to the IP network?
In a dual network, 2 routers provide access to the IP network as shown in the diagram below. However, only
one router can be used as an access point to the network for all IP-PTs.
Therefore, in the diagram below, if router A, whose IP address is assigned as the default gateway IP address
of the IP-PT and IP-EXT16 card, fails, VoIP communications are no longer possible; they are not able to
switch their default gateway from router A to router B to access the IP network.
IP Network
Router A
Default gateway of
the IP-EXT16 card:
Router A
Router B
Default gateway of
the IP-PT:
Router A
2.1 VoIP Requirements
Information about IP Proprietary Telephones 13