illustration
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| Customer || | / <---- Local Area /
===================== / Enterprise network
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| Remote login interface |
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| | | | |
| Access Server |
| | | | |
| | | | |
| COM port interface |
| COM port interface |
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|
==================
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| MODEM |
| | |
| | |
==================
| Access to Remote Service | MOST Commonly Public Switch
-----> | NetWork |
Remote Service Access | Top Usually Public Switch -----> |
|
======================= May be Internet service |
| Suppliers, Notes | | Or Fax Machines | Remote Services |
======================
Command name and code:
COM-Port-Option 44
Client to Access Server Access Server to Client
Signature Text Text
Set-Baudrate 1 101set-DataSize 2 102
SET-PARITY 3 103
Set-stopsize 4 104
SET-Control 5 105
Notify-Linestate 6 106
Notify-modemstate 7 107
FlowControl-suspend 8 108
FlowControl-resume 9 109
Set-Linestate-Mask 10 110
Set-modemState-Mask 11 111
PURGE-DATA 12 112
discuss:
As mentioned earlier, the COM port configuration command is only sent from the customer to the server.
As mentioned earlier, the COM port configuration command is only sent from the customer to the server.
The server does not have a COM port initialization configuration command, only the notification command.
However, in order to allow the server to initialize the COM port configuration, different command values have been established.
1. COM control option protocol
COM control options use standard remote login mechanisms:
IAC WILL COM-Port-Option.
Sender is willing to send a COM port control option command
Iac Wont COM-Port-Option
The sender is unwilling to send a COM port control option command
IAC Do COM-Port-Option
The sender is willing to accept the COM port control option command
IAC DONT COM-Port-Option
The sender is not willing to accept the COM port control option command
Typically, customers use WILL and WONT, accessing the server using DO and DONT.
2.COM port configuration command
Once the protocol is reached, the customer can send commands without time and number of times.
Once the command is processed by the server, each command transmitted from the customer to the server must be acknowledged.
This confirmation will notify the client after the processing of the command will notify the client.
This confirmation will notify the client after the processing of the command will be notified the value set by the Access server.
This Acknowledgment is not used to answernowledge the receipt of the receipt of there
Command, Which is handled at the TCP Protocol Layer.
This is different from the confirmation of the received command processing in the TCP protocol layer.
Its purpose is to inform the customer different from the value being used to the customer request.
For example, a customer may require a server to provide exceeding the baud rate it can provide.
If the customer does not receive this reply within a reasonable time (such as twice the delay), the customer may wish to re-
Send a command, or terminate the dialog.
Different sequence commands may generate invalid COM port configurations.
(E.g:
The data size is valid when the size of 8 digits is valid, and it is recommended to send commands in the following order:
Set-baudrate
2.Set-DataSize
3.Set-Parity
4.set-stopsize
IAC SB COM-Port-Option Signature
Commands for exchange identification flags between customers and servers
2.Set-DataSize
IAC SB COM-Port-Option Signature
Commands for exchange identification flags between customers and servers
If there is no
It can contain manufacturer information, version number information, or any additional information.
If there is an IAC character in
-
The time limit, I hope is ━━━ 10,000 years
━━━━━━━━━━━━━━━━━? ?━???????
