3Com OfficeConnect 3C886A Release Note - page 13
Understanding the Three Dial-in Scenarios
13
Understanding the
Three Dial-in
Scenarios
Before you can use the Dial-in Wizard to set up the LAN Modem for dial-in access,
it may help to understand the three dial-in scenarios available for each of your ten
authorized dial-in users. The scenarios are as follows.
■
Single User Dial-in (single modem or another 56K LAN Modem running NAT)
■
LAN Modem Site-to-Site Dial-in (LAN-to-LAN bidirectional connectivity)
■
Advanced Dial-in (unknown router accessing a LAN Modem)
Single User Dial-in
Single User Dial-in describes a scenario where a client workstation dials into a LAN
Modem via a single analog modem (or another 56K LAN Modem, see below).
With Single-User Dial-in the server-side LAN Modem assigns a single IP address to
the incoming client, as shown in Figure 5.
Figure 5 Single User Dial-in
Single-User Dial-in from Another 56K LAN Modem:
While Single-User
Dial-in provides only one IP address to the dial-in client, the dial-in client may still
be another LAN Modem with several attached workstations. In this case, the
client-side LAN Modem uses NAT to share the single IP address provided by the
server-side LAN Modem, similar to a typical ISP connection, as shown in Figure 6.
Note that unlike the LAN Modem Site-to-Site scenario (described later), the Single
User scenario does not provide for bidirectional LAN-to-LAN connectivity. While
authorized workstations attached to the client LAN Modem can share the
connection to the server LAN Modem, workstations connected to the server LAN
Modem cannot access client-side resources.
Figure 6 Single User Dial-in with NAT
Public telephone
network
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Small office LAN
OfficeConnect
56K LAN Modem
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Server side LAN
Client side LAN
OfficeConnect
56K LAN Modem
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198.162.2.4
OfficeConnect
56K LAN Modem
Client
Server LAN Modem issues
single IP address to
incoming client
Client LAN Modem
uses NAT to translate
issued IP address
Public telephone
network
Client
Server