Draytek 2900 Router User Manual


 
Vigor2900 Series User’s Guide
58
Disable Dial-On-Demand -Specify the connection to be up
when it has traffic on the line. Once there is no traffic over idle
timeout, the connection will be down and never up again during
the schedule.
Idle Timeout Specify the duration (or period) for the schedule.
How often Specify how often the schedule will be applied.
Once -The schedule will be applied just once
Weekdays -Specify which days in one week should perform the
schedule.
Example
Suppose you want to control the PPPoE Internet access connection to be always on (Force On)
from 9:00 to 18:00 for whole week. Other time the Internet access connection should be
disconnected (Force Down).
Office
Hour:
(Force On)
Mon - Sun 9:00 am to 6:00 pm
1. Make sure the PPPoE connection and Call Schedule Setup is working properly.
2. Configure the PPPoE always on from 9:00 to 18:00 for whole week.
3. Configure the Force Down from 18:00 to next day 9:00 for whole week.
Assign these two profiles to the PPPoE Internet access profile. Now, the PPPoE Internet
connection will follow the schedule order to perform Force On or Force Down action
according to the time plan that has been pre-defined in the schedule profiles.
3
3
.
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4
4
N
N
A
A
T
T
S
S
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p
Usually, the router serves as an NAT (Network Address Translation) router. NAT is a
mechanism that one or more private IP addresses can be mapped into a single public one.
Public IP address is usually assigned by your ISP, for which you may get charged. Private IP
addresses are recognized only among internal hosts.
When the outgoing packets destined to some public server on the Internet reach the NAT
router, the router will change its source address into the public IP address of the router, select
the available public port, and then forward it. At the same time, the router shall list an entry in
a table to memorize this address/port-mapping relationship. When the public server response,
the incoming traffic, of course, is destined to the router’s public IP address and the router will
do the inversion based on its table. Therefore, the internal host can communicate with external
host smoothly.
The benefit of the NAT includes:
z Save cost on applying public IP address and apply efficient usage of IP address.
NAT allows the internal IP addresses of local hosts to be translated into one public IP
address, thus you can have only one IP address on behalf of the entire internal hosts.
z Enhance security of the internal network by obscuring the IP address. There are
many attacks aiming victims based on the IP address. Since the attacker cannot be aware
of any private IP addresses, the NAT function can protect the internal network.