Specifications

Chapter 5 Connecting to an ISP
Niagara Considerations
Niagara Release 2.3
Niagara Networking & Connectivity Guide Revised: May 22, 2002
5–5
Figure 5-2 Other ISP connectivity scenarios.
About Connecting to an ISP
The philosophy behind connecting a host to an ISP is different than connecting hosts
with direct dial. With direct dial, the station address book is configured with
information about dialing the remote host. Whenever the application needs to send
data to a remote host, it uses the information in the address book to dial that host.
When the data exchange finishes, the initiating host disconnects.
With an ISP connection, the ISP-connected host is assumed to be always connected.
Therefore, the station does not trigger a connection when it is ready to send data—it
just attempts to send it. When disconnects occur on the ISP-connected host, the host
must be configured to continually retry to connect to the ISP. Data is queued in the
station until the re-connection occurs. Upon successful connection data is passed
between hosts.
Internet
TZO.COM or
another DDNS
provider
Cable Modem
Option 4
Option 3
DSL Modem
Option 1 Option 2
Any
Niagara
Host
Any
Niagara
Host
Web Supervisor
Modem
JACE-NP
Ethernet
connection
Ethernet
connection
Option 5
DSL or Cable Modem
Any
Niagara
Host
Router
providing
Firewall, NAT and DHCP
DSL ISP
DSL or
Cable ISP
Cable ISP
C
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c
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n
e
c
t
i
o
n
D
S
L
c
o
n
n
e
c
t
i
o
n
D
S
L
o
r
c
a
b
l
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c
o
n
n
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Modem
ISP
Network settings assigned
by DHCP on router:
IP address: 192.168.6.5
Default GW: 192.168.6.1
DNS Server: 209.98.36.15
Internal port IP address:
192.168.6.1
External port IP address
(assigned by ISP):
209.98.36.10
Default GW: 209.98.36.10