Crestron NAT, Справочное руководство

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2-Series Feature Crestron NAT
Portmap Page
The PORTMAP page, shown below, permits public access from the external network
onto the internal network. The IP address of the internal network is protected by
reassignment of port numbers via NAT. Port numbers are used to route the packets to
the correct process, or program running on the network-aware device. For example, a
process such as a telnet session receives a temporary port number when the session
starts; data is sent using that port number, and the port number goes out of use when
the session ends. Other port numbers, called "well-known" port numbers, are
permanently assigned; for example, e-mail data under SMTP goes to port number 25.
Other well-known ports are listed at the end of this section.
NOTE: This phase of NAT allows up to 16 port assignments. The value of each
port number can range from 0 to 65535.
PORTMAP Page
NOTE: The three items entered on the page above corresponds to the internal
network, which includes a CP2E and two Isys touchpanels as shown in the example
on page 3.
A process performed by a network-aware device on the internal network can be
initiated from the external network. The NAT protects the anonymity of the internal
network by remapping its known port assignments to ones that it publicizes. Each
publicly accessible process must have an arbitrary external port number assigned to
its known internal port number.
For example, suppose there was a need to remotely upload a project to the Crestron
touchpanel that resides on the internal LAN at IP address 192.168.16.3, as shown on
the PORTMAP page above. Configure the following values.
External Port
The external port field requires an arbitrary number assignment for the known
internal network process. The user on the external network initiates the process by
entering the IP address (of the 2-Series control system with C2ENET-2 card
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Network Address Translator: NAT Reference Guide – DOC. 6001