SMC Networks SMCD3GN2 User Manual page 89

Option
Name
Type
Trigger Port
Target Port
Interval
IP Replacement
Allow sessions initiated from/to the
3 host
rd
Configuring Your Gateway
Figure 48. Trigger Menu
Table 22. Trigger Menu Options
Name for identifying the trigger. The name is for reference purposes only.
The type of protocol you want to use with the trigger. Choices are TCP and UDP. Default is
TCP. For example, to track the H.323 protocol, the protocol type should be TCP.
From and To port ranges of the special application. For example, to track the H.323 protocol,
the From and To ports should be 1720.
From and To port ranges for the target port listening for the special application.
Specify the interval between 50 and 30000 between two continuous sessions. If the interval
exceeds this time interval setting, the sessions are considered to be unrelated.
Select the IP replacement according to the application. Some applications embed the source
host's IP in the datagram and normal NAT would not translate the IP address in the datagram.
To make sure the network address translation is complete, IP replacement is necessary for
these special applications, such as H.323.
Decide whether the sessions can start from/to a third host. To prevent hacker attacks from a
third host, this feature usually is not allowed. However, for some special applications, such as
MGCP in a VOIP application, a session initiated from a third host is permitted. For example,
assume Client A is trying to make a phone call to a host B. Client A tries to communicate with
the Media Gateway Controller (MGC) first and provides host B's number to MGC. Then MGC
checks its own database to find B and communicate with B to provide B the information about
A. B uses this information to communicate directly to A. So initially, A is talking to MGC, but
the final step has B initiating a session to A. If the third-party host-initiated session is not
allowed in this example, the whole communication fails.
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SMCD3GN2 Wireless Cable Modem User Manual
Description