3Com 3C10111C - NBX 100 - Modular Exp Base, Руководство по установке, Страница: 156 / 210

156 C
HAPTER
9: C
ONFIGURING
IP T
ELEPHONY
■
IP On-the-Fly — The NCP provides IP addresses as needed to local
devices. Remote devices obtain IP addresses from the DHCP server, or
you can manually program their IP addresses.
3C10165D E1 Digital Line Cards and 3C10116D T1 Digital Line Cards do
not support the NBX IP On-the Fly feature. If your system uses IP
On-the-Fly, then you must assign a static IP address to the card or use
DHCP to assign an IP address to the card, even if the card will be installed
on the same subnet as the NCP.
6 Click OK .
Configuring IP
On-the-Fly
Before you configure IP On-the-Fly, consider how many addresses you
need.
The number of addresses needed depends on the number of devices that
are likely to use IP communications at one time and in one device
location. For example, if you have twelve devices (four line card ports and
eight telephones) on the NCP subnetwork, and four telephones on other
subnetworks, the number of IP addresses required depends on the
activity on the system.
If an external telephone call arrives on one of the line card ports and the
call is intended for one of the
remote telephones, then the line card port
needs an IP address to participate in the call and obtains one from the IP
On-the-Fly address pool. The remote telephone needs an IP address too.
However, the remote telephone cannot obtain an IP address from the IP
On-the-Fly pool of addresses because it is not on the same subnet as the
NCP. If the remote telephone does not already have an IP address, either
assigned by a DHCP server or manually programmed through the
telephone buttons, it cannot participate in the call.
If an external telephone call arrives on one of the line card ports and the
call is intended for one of the
local telephones, neither the line card port
nor the telephone require an IP address. Both can communicate at the
Ethernet layer (Layer 2).
After you determine the range of IP addresses that you need, configure
IP On-the-Fly:
1 Log in to the NBX NetSet utility using the administrator username and
password.
2 In the NBX NetSet - Main Menu window, click System Configuration .