DCT Antares SB, Руководство пользователя

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3.8. OVER THE AIR
two mechanisms for interrogating the unit via UDP datagrams: Us-
ing the unit’s UDP server port and/or using the unit’s UDP-origin
port. The latter is by default dynamically generated and changed by
the unit as datagrams are sent; but using the TAIP command
XAUO
this value can be fixed.
•
UDP Server Port: Set a value from 1 to 65535 with the com-
mand
XAUP
so the unit always listens to UDP datagrams con-
taining TAIP commands on a fixed, always-available port. No-
tice that the UDP server port solution only works when both
the server sending the TAIP query and the
Antares SB
TM
are
located on the same network (Virtual or Real). This is not the
case on the majority of situations where the unit has Internet
access.
•
UDP Origin Port: The Antares SB
TM
always listens for TAIP
queries sent over UDP datagrams to its UDP origin port. The
UDP origin port is created whenever the unit sends an UDP
datagram to a remote peer; so, if the unit has never sent a
datagram, it will not create and hence listen on this port. Also
notice that the UDP origin port the unit creates is attached to
the remote peer’s address and port (socket); so, an UDP origin
port only listens to UDP datagrams coming from the peer to
which the last report was sent. In fact there is more than one
UDP origin port, there is at least one for each peer the unit has
sent reports to. The UDP origin port is the only solution for
interrogating a unit that is behind a NAT, which is the case on
the majority of units that have Internet access. Notice that the
UDP origin port can be set to a fixed value; this is only useful
on units which work on the same network as the AVL server(s)
(remote peer(s)) because when units work behind a NAT, the
origin port seen by the remote peer is always set by NAT rules,
no matter
Antares SB
TM
uses a fixed value.
The unit may accept TAIP queries coming from any of the 10 possible
UDP origin ports and also from the UDP server port. The server port,
which is only useful when the unit works on the same network as the
AVL server, is not enabled by default.
Server address validation
When working with TCP, a server sending TAIP queries to Antares
SB
TM
is validated through the TCP connection which is always initi-
ated by the unit.
For incoming UDP datagrams there are two mechanism the unit uses
to validate the remote peer (AVL server).
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