MDS entraNET 2400, Инструкция по установке и эксплуатации

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MDS 05-4055A01, Rev. C MDS entraNET System Guide 55
Invisible place holder
Figure 3-21. Conceptual Views of Radio System Usage
The AP includes an embedded terminal server that provides access to
Remote serial ports via an IP or serial connection at the AP. In this
capacity, it acts as a gateway between IP and remote serial devices (thus
the name “serial gateway”), or a transparent over-the-air serial-to-serial
connection.
Serial-to-Serial Services
When the AP transceiver has remote serial units and is primarily passing
RS-232 (serial-based) traffic, it may be necessary to implement
serial-to-serial interface transfers, as shown in the lower part of
Figure 3-21 . Additional information for serial-to-serial wireless net-
works is provided on Pages 124 and 132 of this manual.
IP-to-Serial Services
When the AP transceiver is used as an IP-to-serial gateway, two types
of IP terminal services are available—TCP and UDP. TCP provides a
connection-oriented link, with end-to-end acknowledgment of data.
This requires some added overhead, but provides confirmation that data
has been successfully conveyed, which may be needed for mission-crit-
ical applications.
UDP, on the other hand, provides a best-effort delivery service with less
overhead than TCP. It basically broadcasts data, transmitting informa-
tion packets without an expected acknowledgment. This method mini-
mizes overhead requirements and is acceptable for repetitive exchanges
of information, where an occasional missed packet would not
affect performance.
ACCESS POINT
(AP)
Ethernet
IP-TO-LOCAL SERIAL EXAMPLE
Serial
(showing port steering)
ACCESS POINT
(AP)
REMOTE 1
REMOTE 2
REMOTE 3
REMOTE 4
Serial Data
Serial Data
Serial Data
Serial Data
Serial Data
SERIAL-TO-SERIAL EXAMPLE
(Showing Remote port routing)