Davolink DV-302, Руководство по эксплуатации

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DV-302 OPERATION MANUAL
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Range, the resulting ports set in the Target Range are opened for incoming (or sometimes
referred to as bi-
directional ports) data. If no outgoing traffic is detected on the “Trigger Range”
ports for 10 minutes, the “Target Range” ports will close. This is a safer method for opening
specific ports for special applications (ex., video conferencing programs, interactive gaming, file
transfer in chat programs, etc.) because they are dynamically triggered and not held open
constantly or erroneously left open via the administrator router and exposed for potential
hackers to discover.
Port Triggers should be set up for commonly-used special applications requiring bi-directional
communications on specific port numbers in order to operate correctly. One of the most
common applications that requires this are video conferencing applications that require
separate IP ports for video and audio transmissions to management servers in the public
(WAN) network.
For example, a special application is used to communicate with any PC on the Private LAN
that tries to first connect with outgoing port numbers in the range of 1024 - 5180 and
consequently triggers the opening of ports 1024 - 58,600 for bi-directional traffic on both TCP
and UDP. This operation can only be effective for a single PC at a time, but can be used for
any PC at a later time after the trigger is timed-out. This is a very effective method for allowing
various Users on the Private LAN to use a common application at different times without the
security risk of leaving IP ports open all the time and the network PCs unprotected.