User manual
14
PPP SETTINGS
The PPP Username, PPP password and the PPPoE Service Name entries are
dependent on the particular requirements of the ISP. The user name can be a
maximum of 256 characters and the password a maximum of 32 characters in
length. For Authentication Method, choose from AUTO, PAP, CHAP, and MSCHAP.
ENABLE FULLCONE NAT
This option becomes available when NAT is enabled. Known as one-to-one NAT, all
requests from the same internal IP address and port are mapped to the same
external IP address and port. An external host can send a packet to the internal host,
by sending a packet to the mapped external address.
DIAL ON DEMAND
The CT-5072T can be configured to disconnect if there is no activity for a period of
time by selecting the Dial on demand checkbox . You must also enter an
inactivity timeout period in the range of 1 to 4320 minutes.
PPP IP EXTENSION
The PPP IP Extension is a special feature deployed by some service providers.
Unless your service provider specifically requires this setup, do not select it.
PPP IP Extension does the following:
Allows only one PC on the LAN.
Disables NAT and Firewall.
The device becomes the default gateway and DNS server to the PC
through DHCP using the LAN interface IP address.
The device extends the IP subnet at the remote service provider to the
LAN PC. i.e. the PC becomes a host belonging to the same IP subnet.
The device bridges the IP packets between WAN and LAN ports, unless
the packet is addressed to the device’s LAN IP address.
The public IP address assigned by the remote side using the PPP/IPCP
protocol is actually not used on the WAN PPP interface. Instead, it is
forwarded to the PC LAN interface through DHCP. Only one PC on the
LAN can be connected to the remote, since the DHCP server within the
device has only a single IP address to assign to a LAN device.
ENABLE NAT
If the LAN uses private IP addresses, this checkbox must be selected.
The NAT submenu will be added to the Advanced Setup menu after reboot.
This function consumes system resources and thus may impact performance.
If the LAN uses public IP addresses, this checkbox must not be selected.
The NAT submenu will be removed from the Advanced Setup menu after reboot.
ENABLE FIREWALL
To enable IP packet filtering, tick this checkbox . The Advanced Setup Security
IP Filtering option will appear on the main menu after reboot. Disable this function
when not required for improved performance.