3Com Dual 56K Network Card User Manual


 
Configuring Additional Service Providers 75
With NAT enabled, the LAN Modem makes translations between a single
(Internet-routable) IP address issued to it dynamically by the ISP and individual IP
addresses of the computers on the LAN (these are also dynamically assigned, but
by the LAN Modem). This translation allows multiple users on the LAN to access
the ISP by appearing to be a single connection with a single IP address. To better
understand how NAT translation works, refer to the description of NAT in
Appendix A, “Networking Primer.”
14 In the WAN Link IP Address and Subnet mask fields, if the ISP to which you are
connecting assigns you a static IP address and subnet mask, enter those values
here. Otherwise, leave these fields empty.
15 For Allow Automatic Call Initiation, leave the default setting which is Yes.
If you select No, you will have to manually launch a call to this service provider
every time you want to connect. You may want to change this field to No later on
if you find that calls are being connected unintentionally as a result of packets
generated by other computers on the LAN.
16 In the Default Workstation for Incoming Packets field, specify the workstation to
which all unsolicited TCP/UDP packets should be delivered.
Note that if the Enable Intelligent NAT field is set to Yes, the LAN Modem first
attempts to deliver the unsolicited TCP/UDP packets to the workstation that is
currently communicating with the remote host that has generated these packets.
Only if no such workstation is found are the packets delivered to the specified
default workstation.
17 For Enable Intelligent NAT, it is recommended that you leave the default setting,
which is Yes, in order for the LAN Modem to better support Internet applications
and games.
The LAN Modem delivers all unsolicited TCP/UDP packets to the workstation that
is currently communicating with the remote host that has generated these
packets. If you set this field to No, all unsolicited TCP/UDP packets are delivered to
the default workstation.
18 In the Default Workstation for Incoming Packets field, specify the workstation to
which all unsolicited TCP/UDP packets should be delivered.
Note that if the Enable Intelligent NAT field is set to Yes, the LAN Modem first
attempts to deliver the unsolicited TCP/UDP packets to the workstation that is
currently communicating with the remote host that has generated these packets.
Only if no such workstation is found are the packets delivered to the specified
default workstation.
19 Click Submit.
20 Advanced users can review or make changes to the V.90 modem settings
associated with this service provider by clicking the Modem Settings button. To
leave these values set to their defaults, click Submit. To change these settings,
refer to “Configuring V.90 Modem Control Parameters.”
21 To configure a connection to another ISP, repeat steps 1 through 19.
If your service provider requires that you create a connection script, refer to “Using
a Connection Script”.
If you wish to password-protect the configuration profile of the Dual 56K LAN
Modem, refer to “Locking and Unlocking the Configuration.”