RFC2217 日本語訳
2217 Telnet Com Port Control Option. G. Clark. October 1997. (Format: TXT=31664 bytes) (Status: EXPERIMENTAL)
プログラムでの自動翻訳です。
英語原文
Network Working Group G. Clark Request for Comments: 2217 Cisco Systems, Inc. Category: Experimental October 1997
Network Working Group G. Clark Request for Comments: 2217 Cisco Systems, Inc. Category: Experimental October 1997
Telnet Com Port Control Option
Telnet Com Port Control Option
Status of this Memo
Status of this Memo
This memo defines an Experimental Protocol for the Internet community. This memo does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited.
This memo defines an Experimental Protocol for the Internet community. This memo does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited.
Introduction
Introduction
This memo proposes a protocol to allow greater use of modems attached to a network for outbound dialing purposes.
This memo proposes a protocol to allow greater use of modems attached to a network for outbound dialing purposes.
Table of Contents
1. Negotiation of the Com Port
Control Option Protocol .................. 5
2. Com Port Configuration Commands .................. 6
Version
Baud Rate
Data Bit Size
Parity
Stop Bit size
3. Special Com Port Control Commands ................. 8
XON/XOFF Flow Control
HARDWARE Flow Control
BREAK Signal
DTR Signal
RTS Signal
4. Notification of Com Port and .................. 12
Modem Line Changes
5. Flow Control .................. 13
6. Security Considerations .................. 13
7. Author's Address .................. 14
8. Reference Section .................. 14
Table of Contents 1. Negotiation of the Com Port Control Option Protocol .................. 5 2. Com Port Configuration Commands .................. 6 Version Baud Rate Data Bit Size Parity Stop Bit size 3. Special Com Port Control Commands ................. 8 XON/XOFF Flow Control HARDWARE Flow Control BREAK Signal DTR Signal RTS Signal 4. Notification of Com Port and .................. 12 Modem Line Changes 5. Flow Control .................. 13 6. Security Considerations .................. 13 7. Author's Address .................. 14 8. Reference Section .................. 14
Discussion
Discussion
The Telnet protocol defines an interactive, character-oriented communications session. It was originally designed to establish a session between a client and a remote login service running on a host [5].
The Telnet protocol defines an interactive, character-oriented communications session. It was originally designed to establish a session between a client and a remote login service running on a host [5].
Clark Experimental [Page 1] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 1] RFC 2217 Telnet Com Port Control Option October 1997
Many new business functions require a person to connect to remote services to retrieve or deposit information. By in large, these remote services are accessed via an async dial up connection. This new class of functions include:
Many new business functions require a person to connect to remote services to retrieve or deposit information. By in large, these remote services are accessed via an async dial up connection. This new class of functions include:
- dial up connections to the Internet
- connecting to bulletin boards
- connecting to internal and external databases
- sending and receiving faxes.
- dial up connections to the Internet - connecting to bulletin boards - connecting to internal and external databases - sending and receiving faxes.
The general nature of this new class of function requires an interactive, character-oriented communications session via an async modem. This is typically known as outbound modem dialing.
The general nature of this new class of function requires an interactive, character-oriented communications session via an async modem. This is typically known as outbound modem dialing.
To help defer the cost of installing and maintaining additional phone lines which may be used very little per person, many equipment manufacturers have added the ability to establish a Telnet session directly to the outbound ports on many of the most popular access servers and routers, here after referred to as access servers.
To help defer the cost of installing and maintaining additional phone lines which may be used very little per person, many equipment manufacturers have added the ability to establish a Telnet session directly to the outbound ports on many of the most popular access servers and routers, here after referred to as access servers.
However, the current Telnet protocol definitions are not sufficient to fully support this new use. There are three new areas of functionality which need to be added to the Telnet protocol to successfully support the needs of outbound modem dialing. These are:
However, the current Telnet protocol definitions are not sufficient to fully support this new use. There are three new areas of functionality which need to be added to the Telnet protocol to successfully support the needs of outbound modem dialing. These are:
- The ability for the client to send com port configuration
information to the access server which is connected to the
outbound modem. This is needed to ensure the data being
transmitted and received by the modem is formatted correctly
at the byte level.
- The ability for the client to send com port configuration information to the access server which is connected to the outbound modem. This is needed to ensure the data being transmitted and received by the modem is formatted correctly at the byte level.
- The ability for the access server to inform the client of any
modem line or signal changes such as RLSD changes (carrier
detect). This information is vital, since many client software
packages use this information to determine if a session with the
remote service has been established. RLSD changes are also
used for signaling in Class I faxing [6].
- The ability for the access server to inform the client of any modem line or signal changes such as RLSD changes (carrier detect). This information is vital, since many client software packages use this information to determine if a session with the remote service has been established. RLSD changes are also used for signaling in Class I faxing [6].
- The ability to manage flow control between the client and
the access server which does not interfere with the flow
control mechanisms used by the session between the client and
the remote service. Unfortunately RFC 1372 "Telnet Remote
Flow Control Option" [2] can not be used for this purpose
because it relies on sending XON/XOFF style characters which
maybe transmitted or received as a normal course of the
client / remote service session.
- The ability to manage flow control between the client and the access server which does not interfere with the flow control mechanisms used by the session between the client and the remote service. Unfortunately RFC 1372 "Telnet Remote Flow Control Option" [2] can not be used for this purpose because it relies on sending XON/XOFF style characters which maybe transmitted or received as a normal course of the client / remote service session.
Clark Experimental [Page 2] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 2] RFC 2217 Telnet Com Port Control Option October 1997
Though this discussion has focused on outbound modem dialing as the primary use of this protocol, the protocol can also be used for any serial device attached to an access server. Such devices could be:
Though this discussion has focused on outbound modem dialing as the primary use of this protocol, the protocol can also be used for any serial device attached to an access server. Such devices could be:
- serial printers
- plotters
- monitoring devices such as pipe line monitors or medical
monitors
- general office equipment such as photo-copiers and cash
registers
- serial printers - plotters - monitoring devices such as pipe line monitors or medical monitors - general office equipment such as photo-copiers and cash registers
Definition of Terms
Definition of Terms
Access Server - Any network device which accepts Telnet sessions
and passes the data received to a com port, and
passes data received from the com port to the client
via the Telnet session.
Access Server - Any network device which accepts Telnet sessions and passes the data received to a com port, and passes data received from the com port to the client via the Telnet session.
Baud Rate - For the purposes of this document, baud rate will
mean the communications of data in bits per second.
Baud Rate - For the purposes of this document, baud rate will mean the communications of data in bits per second.
Client - Any network device which initiates a Telnet session
to an access server.
Client - Any network device which initiates a Telnet session to an access server.
Outbound - Transmission of data from the modem attached to the
access server to a remote service.
Outbound - Transmission of data from the modem attached to the access server to a remote service.
Inbound - Transmission of data from the remote service to the
modem attached to the access server.
Inbound - Transmission of data from the remote service to the modem attached to the access server.
Remove Service - Any service which accepts dial-up connections,
including fax machines.
Remove Service - Any service which accepts dial-up connections, including fax machines.
Clark Experimental [Page 3] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 3] RFC 2217 Telnet Com Port Control Option October 1997
Illustration
Illustration
=====================
| |
| CLIENT |\
| | \ < ---- Local Area /
===================== \ Enterprise Network
\
\
=============================
| Telnet Interface |
| | |
| | |
| ACCESS SERVER | |
| | |
| | |
| Com Port Interface |
=============================
|
|
==================
| |
| MODEM |
| |
==================
|
Access to Remote Service |
most commonly Public Switched ----->|
Network |
|
|
======================
Could be Internet Service | |
Provider, Bulletin Board | |
or FAX machine | REMOTE SERVICE |
| |
| |
======================
===================== | | | CLIENT |\ | | \ < ---- Local Area / ===================== \ Enterprise Network \ \ ============================= | Telnet Interface | | | | | | | | ACCESS SERVER | | | | | | | | | Com Port Interface | ============================= | | ================== | | | MODEM | | | ================== | Access to Remote Service | most commonly Public Switched ----->| Network | | | ====================== Could be Internet Service | | Provider, Bulletin Board | | or FAX machine | REMOTE SERVICE | | | | | ======================
Command Names and Codes:
COM-PORT-OPTION 44
Command Names and Codes: COM-PORT-OPTION 44
Clark Experimental [Page 4] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 4] RFC 2217 Telnet Com Port Control Option October 1997
Client to Access Server Access Server to Client
SIGNATURE text text
SET-BAUDRATE 1 101
SET-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
Client to Access Server Access Server to Client SIGNATURE text text SET-BAUDRATE 1 101 SET-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
Discussion: As initially proposed, com port configuration
commands are only sent from the client to the access
server. There is no current vision that the access
server would initiate the use of a com port configuration
command, only the notify commands. However, to allow for
access server initiated com port configurations different
command values have been established.
Discussion: As initially proposed, com port configuration commands are only sent from the client to the access server. There is no current vision that the access server would initiate the use of a com port configuration command, only the notify commands. However, to allow for access server initiated com port configurations different command values have been established.
1. Negotiation of the Com Port Control Option Protocol
1. Negotiation of the Com Port Control Option Protocol
The negotiation of the com port control option protocol uses the standard Telnet negotiation protocol mechanism:
The negotiation of the com port control option protocol uses the standard Telnet negotiation protocol mechanism:
IAC WILL COM-PORT-OPTION
The sender of this command is willing to send com port
control option commands.
IAC WONT COM-PORT-OPTION
The sender of this command refuses to send com port
control option commands.
IAC DO COM-PORT-OPTION
The sender of this command is willing to accept com port
control option commands.
IAC DONT COM-PORT-OPTION
The sender of this command refuses to accept com port control
options commands.
IAC WILL COM-PORT-OPTION The sender of this command is willing to send com port control option commands. IAC WONT COM-PORT-OPTION The sender of this command refuses to send com port control option commands. IAC DO COM-PORT-OPTION The sender of this command is willing to accept com port control option commands. IAC DONT COM-PORT-OPTION The sender of this command refuses to accept com port control options commands.
Typically a client will use WILL and WONT, while an access server
will use DO and DONT.
Typically a client will use WILL and WONT, while an access server will use DO and DONT.
Clark Experimental [Page 5] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 5] RFC 2217 Telnet Com Port Control Option October 1997
2. Com Port Configuration Commands
2. Com Port Configuration Commands
Once DO and WILL have been negotiated, the client may send any of the following commands. The client can send these commands at any time and multiple times throughout the Telnet session. Each command transmitted from the client to the access server must be acknowledged once the command has been processed by the access server. This confirmation informs the client of the value set at the access server after the processing of the command. This acknowledgment is not used to acknowledge the receipt of the command, which is handled at the TCP protocol layer. Its purpose is to inform the client of the value in use, which may be different than the value requested in the client's command. For example, the client may request a baud rate higher than the access service can provide. If an acknowledgment is not received by the client within a reasonable time (such as twice the delay acknowledgment timer), the client may wish to resend the command or terminate the session.
Once DO and WILL have been negotiated, the client may send any of the following commands. The client can send these commands at any time and multiple times throughout the Telnet session. Each command transmitted from the client to the access server must be acknowledged once the command has been processed by the access server. This confirmation informs the client of the value set at the access server after the processing of the command. This acknowledgment is not used to acknowledge the receipt of the command, which is handled at the TCP protocol layer. Its purpose is to inform the client of the value in use, which may be different than the value requested in the client's command. For example, the client may request a baud rate higher than the access service can provide. If an acknowledgment is not received by the client within a reasonable time (such as twice the delay acknowledgment timer), the client may wish to resend the command or terminate the session.
Though the commands may be sent from the client to the access server in any sequence, there are sequences which may result in invalid configurations for the com port (for example: EVEN parity is only valid if the data size is set to less than 8 bits). Thus it is recommended that commands be issued in the following sequence:
Though the commands may be sent from the client to the access server in any sequence, there are sequences which may result in invalid configurations for the com port (for example: EVEN parity is only valid if the data size is set to less than 8 bits). Thus it is recommended that commands be issued in the following sequence:
1. SET-BAUDRATE
2. SET-DATASIZE
3. SET-PARITY
4. SET-STOPSIZE
1. SET-BAUDRATE 2. SET-DATASIZE 3. SET-PARITY 4. SET-STOPSIZE
IAC SB COM-PORT-OPTION SIGNATURE <text> IAC SE
This command may be sent by either the client or the access
server to exchange signature information. If the command is
sent without <text> it is a request from the sender to receive
the signature text of the receiver. The text may be a
combination of any characters. There is no structure to the
<text> field. It may contain manufacturer information, version
number information, or any other information desired. If an
IAC character appears in the text it must be translated to
IAC-IAC to avoid conflict with the IAC which terminates
the command.
IAC SB COM-PORT-OPTION SIGNATURE <text> IAC SE This command may be sent by either the client or the access server to exchange signature information. If the command is sent without <text> it is a request from the sender to receive the signature text of the receiver. The text may be a combination of any characters. There is no structure to the <text> field. It may contain manufacturer information, version number information, or any other information desired. If an IAC character appears in the text it must be translated to IAC-IAC to avoid conflict with the IAC which terminates the command.
IAC SB COM-PORT-OPTION SET-BAUD <value(4)> IAC SE
This command is sent by the client to the access server to set
the baud rate of the com port. The value is four octets (4 bytes).
The value is represented in network standard format. The value
is the baud rate being requested. A special case is the value 0.
If the value is zero the client is requesting the current baud
rate of the com port on the access server.
IAC SB COM-PORT-OPTION SET-BAUD <value(4)> IAC SE This command is sent by the client to the access server to set the baud rate of the com port. The value is four octets (4 bytes). The value is represented in network standard format. The value is the baud rate being requested. A special case is the value 0. If the value is zero the client is requesting the current baud rate of the com port on the access server.
Clark Experimental [Page 6] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 6] RFC 2217 Telnet Com Port Control Option October 1997
Discussion: Though baud rates used today form a very sparse space,
and the initial version of the option used an index
based baud rate table, after much discussion with a
number of groups it has been determined that the
actual baud rate should be used. There are two main
reasons. 1) It limits the number of updates to the
option as faster baud rates come into use,
2) It provides the greatest amount of flexibility
in the selection of the baud rates.
Discussion: Though baud rates used today form a very sparse space, and the initial version of the option used an index based baud rate table, after much discussion with a number of groups it has been determined that the actual baud rate should be used. There are two main reasons. 1) It limits the number of updates to the option as faster baud rates come into use, 2) It provides the greatest amount of flexibility in the selection of the baud rates.
IAC SB COM-PORT-OPTION SET-DATASIZE <value> IAC SE
This command is sent by the client to the access server to set
the data bit size. The command can also be sent to query the
current data bit size. The value is one octet (byte). The value
is an index into the following value table:
IAC SB COM-PORT-OPTION SET-DATASIZE <value> IAC SE This command is sent by the client to the access server to set the data bit size. The command can also be sent to query the current data bit size. The value is one octet (byte). The value is an index into the following value table:
Value Data Bit Size
0 Request Current Data Bit Size
1 Available for Future Use
2 Available for Future Use
3 Available for Future Use
4 Available for Future Use
5 5
6 6
7 7
8 8
9-127 Available for Future Use
Value Data Bit Size 0 Request Current Data Bit Size 1 Available for Future Use 2 Available for Future Use 3 Available for Future Use 4 Available for Future Use 5 5 6 6 7 7 8 8 9-127 Available for Future Use
Discussion: There are only eight possible values for the data bit
size, only four have ever been used historically and
only two are commonly used today. The use of the
command-value format is recommended to preserve
consistency with other commands. It also reduces the
number of commands defined in the protocol, and
allows for future expansion.
Discussion: There are only eight possible values for the data bit size, only four have ever been used historically and only two are commonly used today. The use of the command-value format is recommended to preserve consistency with other commands. It also reduces the number of commands defined in the protocol, and allows for future expansion.
IAC SB COM-PORT-OPTION SET-PARITY <value> IAC SE
This command is sent by the client to the access server to set
the parity. The command can also be sent to query the current
parity. The value is one octet (byte). The value is an index into
the following value table:
IAC SB COM-PORT-OPTION SET-PARITY <value> IAC SE This command is sent by the client to the access server to set the parity. The command can also be sent to query the current parity. The value is one octet (byte). The value is an index into the following value table:
Value Parity [1]
0 Request Current Data Size
1 NONE
2 ODD
3 EVEN
4 MARK
Value Parity [1] 0 Request Current Data Size 1 NONE 2 ODD 3 EVEN 4 MARK
Clark Experimental [Page 7] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 7] RFC 2217 Telnet Com Port Control Option October 1997
5 SPACE
6-127 Available for Future Use
5 SPACE 6-127 Available for Future Use
Discussion: There are only five possible values for parity
commonly used today. The use of the command-value
format is recommended to preserve consistency with
other commands.
Discussion: There are only five possible values for parity commonly used today. The use of the command-value format is recommended to preserve consistency with other commands.
IAC SB COM-PORT-OPTION SET-STOPSIZE <value> IAC SE
This command is sent by the client to the access server to set
the number of stop bits. The command can also be sent to query
the current stop bit size. The value is one octet (byte). The
value is an index into the following value table:
IAC SB COM-PORT-OPTION SET-STOPSIZE <value> IAC SE This command is sent by the client to the access server to set the number of stop bits. The command can also be sent to query the current stop bit size. The value is one octet (byte). The value is an index into the following value table:
Value Stop Bit Size
0 Request Current Data Size
1 1
2 2
3 1.5
4-127 Available for Future Use
Value Stop Bit Size 0 Request Current Data Size 1 1 2 2 3 1.5 4-127 Available for Future Use
Discussion: Stop bit 1.5 is supported by most com port hardware
only if data size is set to 5 bits. It is not
commonly used.
Discussion: Stop bit 1.5 is supported by most com port hardware only if data size is set to 5 bits. It is not commonly used.
3. Special Com Port Control Commands
3. Special Com Port Control Commands
The client can send this command to the access server at any time and multiple times throughout the Telnet session. Each command transmitted from the client to the access server is acknowledged with a confirmation of the command and the actual value set. The client should expect a response within a reasonable time (such as twice the delay acknowledgment timer). The client may wish to resend any command which is not acknowledged or terminate the session.
The client can send this command to the access server at any time and multiple times throughout the Telnet session. Each command transmitted from the client to the access server is acknowledged with a confirmation of the command and the actual value set. The client should expect a response within a reasonable time (such as twice the delay acknowledgment timer). The client may wish to resend any command which is not acknowledged or terminate the session.
IAC SB COM-PORT-OPTION SET-CONTROL <value> IAC SE
This command is sent by the client to the access server to set
special com port options. The command can also be sent to query
the current option value. The value is one octet (byte). The
value is an index into the following value table:
IAC SB COM-PORT-OPTION SET-CONTROL <value> IAC SE This command is sent by the client to the access server to set special com port options. The command can also be sent to query the current option value. The value is one octet (byte). The value is an index into the following value table:
Value Control Commands
0 Request Com Port Flow Control Setting
(outbound/both)
1 Use No Flow Control (outbound/both)
2 Use XON/XOFF Flow Control (outbound/both)
3 Use HARDWARE Flow Control (outbound/both)
Value Control Commands 0 Request Com Port Flow Control Setting (outbound/both) 1 Use No Flow Control (outbound/both) 2 Use XON/XOFF Flow Control (outbound/both) 3 Use HARDWARE Flow Control (outbound/both)
Clark Experimental [Page 8] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 8] RFC 2217 Telnet Com Port Control Option October 1997
4 Request BREAK State
5 Set BREAK State ON
6 Set BREAK State OFF
7 Request DTR Signal State
8 Set DTR Signal State ON
9 Set DTR Signal State OFF
10 Request RTS Signal State
11 Set RTS Signal State ON
12 Set RTS Signal State OFF
13 Request Com Port Flow Control Setting (inbound)
14 Use No Flow Control (inbound)
15 Use XON/XOFF Flow Control (inbound)
16 Use HARDWARE Flow Control (inbound)
17 Use DCD Flow Control (outbound/both)
18 Use DTR Flow Control (inbound)
19 Use DSR Flow Control (outbound/both)
20-127 Available for Future Use
4 Request BREAK State 5 Set BREAK State ON 6 Set BREAK State OFF 7 Request DTR Signal State 8 Set DTR Signal State ON 9 Set DTR Signal State OFF 10 Request RTS Signal State 11 Set RTS Signal State ON 12 Set RTS Signal State OFF 13 Request Com Port Flow Control Setting (inbound) 14 Use No Flow Control (inbound) 15 Use XON/XOFF Flow Control (inbound) 16 Use HARDWARE Flow Control (inbound) 17 Use DCD Flow Control (outbound/both) 18 Use DTR Flow Control (inbound) 19 Use DSR Flow Control (outbound/both) 20-127 Available for Future Use
Discussion: Flow control options were divided into inbound and
outbound to take full advantage of existing
programming interfaces and access server
capabilities.
Discussion: Flow control options were divided into inbound and outbound to take full advantage of existing programming interfaces and access server capabilities.
Discussion: The outbound values should set flow control for both
outbound and inbound. If inbound is to be, or can
be, set separately it should be done after the
setting of the outbound value.
Discussion: The outbound values should set flow control for both outbound and inbound. If inbound is to be, or can be, set separately it should be done after the setting of the outbound value.
Discussion: If the access server is not able to set inbound flow
control differently from the outbound flow control,
it should ignore the inbound flow control commands
and set the flow control option based on the outbound
flow control commands only.
Discussion: If the access server is not able to set inbound flow control differently from the outbound flow control, it should ignore the inbound flow control commands and set the flow control option based on the outbound flow control commands only.
IAC SB COM-PORT-OPTION SET-LINESTATE-MASK <value> IAC SE
This command is sent by the client to the access server to set a
bit mask for the sending of the NOTIFY-LINESTATE option (see
section 4). When the LINESTATE changes on the access server, the
access server will "AND" the new LINESTATE with the LINESTATE-
MASK. If the result is not zero, the access server will send the
result of the "AND" as the value in a NOTIFY-LINESTATE com port
option. If more than one bit satisfies the LINESTATE-MASK, only
one NOTIFY-LINESTATE, with all the satisfying bits, will be sent
to the client. The SET-LINESTATE-MASK may be any combination of
bits as listed below. These are the same bit values used in the
NOTIFY-LINESTATE option. The SET-LINESTATE-MASK values are based
on the most popular UART (com port control chip) in use [1].
IAC SB COM-PORT-OPTION SET-LINESTATE-MASK <value> IAC SE This command is sent by the client to the access server to set a bit mask for the sending of the NOTIFY-LINESTATE option (see section 4). When the LINESTATE changes on the access server, the access server will "AND" the new LINESTATE with the LINESTATE- MASK. If the result is not zero, the access server will send the result of the "AND" as the value in a NOTIFY-LINESTATE com port option. If more than one bit satisfies the LINESTATE-MASK, only one NOTIFY-LINESTATE, with all the satisfying bits, will be sent to the client. The SET-LINESTATE-MASK may be any combination of bits as listed below. These are the same bit values used in the NOTIFY-LINESTATE option. The SET-LINESTATE-MASK values are based on the most popular UART (com port control chip) in use [1].
Clark Experimental [Page 9] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 9] RFC 2217 Telnet Com Port Control Option October 1997
Bit Position Value Meaning
7 128 Time-out Error
6 64 Transfer Shift Register Empty
5 32 Transfer Holding Register Empty
4 16 Break-detect Error
3 8 Framing Error
2 4 Parity Error
1 2 Overrun Error
0 1 Data Ready
Bit Position Value Meaning 7 128 Time-out Error 6 64 Transfer Shift Register Empty 5 32 Transfer Holding Register Empty 4 16 Break-detect Error 3 8 Framing Error 2 4 Parity Error 1 2 Overrun Error 0 1 Data Ready
Discussion: The SET-LINESTATE-MASK value of 0 will prevent the
access server from sending NOTIFY-LINESTATE options
to the client.
Discussion: The SET-LINESTATE-MASK value of 0 will prevent the access server from sending NOTIFY-LINESTATE options to the client.
Discussion: The SET-LINESTATE-MASK value of 255 will allow the
access server to send a NOTIFY-LINESTATE option to
the client each time the LINESTATE changes on the
access server.
Discussion: The SET-LINESTATE-MASK value of 255 will allow the access server to send a NOTIFY-LINESTATE option to the client each time the LINESTATE changes on the access server.
Discussion: The initial LINESTATE-MASK at the access server is 0.
Discussion: The initial LINESTATE-MASK at the access server is 0.
Discussion: The client does not have to send a new
SET-LINESTATE-MASK after receiving a NOTIFY-
LINESTATE. The LINESTATE-MASK on the access server
is retained until set by the client or reset at the
start of a new Telnet session.
Discussion: The client does not have to send a new SET-LINESTATE-MASK after receiving a NOTIFY- LINESTATE. The LINESTATE-MASK on the access server is retained until set by the client or reset at the start of a new Telnet session.
IAC SB COM-PORT-OPTION SET-MODEMSTATE-MASK <value> IAC SE
This command is sent by the client to the access server to set a
bit mask for the sending of the NOTIFY-MODEMSTATE option (see
section 4). When the MODEMSTATE changes on the access server,
the access server will "AND" the new MODEMSTATE with the
MODEMSTATE-MASK. If the result is not zero, the access server
will send the result of the "AND" as the value in a NOTIFY-
MODEMSTATE com port option. If more than one bit satisfies the
MODEMSTATE-MASK, only one NOTIFY-MODEMSTATE, with all the
satisfying bits, will be sent to the client. The SET-
MODEMSTATE-MASK may be any combination of bits as listed below.
These are the same bit values used in the NOTIFY-MODEMSTATE
option. The SET-MODEMSTATE-MASK values are based on the most
popular UART (com port control chip) in use [1].
IAC SB COM-PORT-OPTION SET-MODEMSTATE-MASK <value> IAC SE This command is sent by the client to the access server to set a bit mask for the sending of the NOTIFY-MODEMSTATE option (see section 4). When the MODEMSTATE changes on the access server, the access server will "AND" the new MODEMSTATE with the MODEMSTATE-MASK. If the result is not zero, the access server will send the result of the "AND" as the value in a NOTIFY- MODEMSTATE com port option. If more than one bit satisfies the MODEMSTATE-MASK, only one NOTIFY-MODEMSTATE, with all the satisfying bits, will be sent to the client. The SET- MODEMSTATE-MASK may be any combination of bits as listed below. These are the same bit values used in the NOTIFY-MODEMSTATE option. The SET-MODEMSTATE-MASK values are based on the most popular UART (com port control chip) in use [1].
Clark Experimental [Page 10] RFC 2217 Telnet Com Port Control Option October 1997
Clark Experimental [Page 10] RFC 2217 Telnet Com Port Control Option October 1997
Bit Position Value Meaning
7 128 Receive Line Signal Detect
(also known as Carrier Detect)
6 64 Ring Indicator
5 32 Data-Set-Ready Signal State
4 16 Clear-To-Send Signal State
3 8 Delta Receive Line Signal Detect
2 4 Trailing-edge Ring Detector
1 2 Delta Data-Set-Ready
0 1 Delta Clear-To-Send
Bit Position Value Meaning 7 128 Receive Line Signal Detect (also known as Carrier Detect) 6 64 Ring Indicator 5 32 Data-Set-Ready Signal State 4 16 Clear-To-Send Signal State 3 8 Delta Receive Line Signal Detect 2 4 Trailing-edge Ring Detector 1 2 Delta Data-Set-Ready 0 1 Delta Clear-To-Send
Discussion: The SET-MODEMSTATE-MASK value of 0 will prevent the
access server from sending NOTIFY-MODEMSTATE options
to the client.
Discussion: The SET-MODEMSTATE-MASK value of 0 will prevent the access server from sending NOTIFY-MODEMSTATE options to the client.
Discussion: The SET-MODEMSTATE-MASK value of 255 will allow the
access server to send a NOTIFY-MODEMSTATE option to
the client each time the MODEMSTATE changes on the
access server.
Discussion: The SET-MODEMSTATE-MASK value of 255 will allow the access server to send a NOTIFY-MODEMSTATE option to the client each time the MODEMSTATE changes on the access server.
Discussion: The initial MODEMSTATE-MASK at the access server
is 255.
Discussion: The initial MODEMSTATE-MASK at the access server is 255.
Discussion: The client does not have to send a new
SET-MODEMSTATE-MASK after receiving a NOTIFY-
MODEMSTATE. The MODEMSTATE-MASK on the access server
is retained until set by the client or reset at the
start of a new Telnet session.
Discussion: The client does not have to send a new SET-MODEMSTATE-MASK after receiving a NOTIFY- MODEMSTATE. The MODEMSTATE-MASK on the access server is retained until set by the client or reset at the start of a new Telnet session.
IAC SB COM-PORT-OPTION PURGE-DATA <value> IAC SE
This command is sent by the client to the access server to
instruct the access server to immediately clear all data from the
buffer or buffers referenced by the value. The value is one
octet (byte). The value is an index into the following value
table:
IAC SB COM-PORT-OPTION PURGE-DATA <value> IAC SE This command is sent by the client to the access server to instruct the access server to immediately clear all data from the buffer or buffers referenced by the value. The value is one octet (byte). The value is an index into the following value table:
Value Purge Data Buffer
0 Available for Future Use
1 Purge access server receive data buffer
2 Purge access server transmit data buffer
3 Purge both the access server receive data
buffer and the access server transmit data
buffer
4-127 Available for Future Use
値、Future Use1Purgeアクセス・サーバー受信データバッファ2Purgeアクセス・サーバーがデータを送るので、Purge Data Buffer0Availableが受信データがバッファリングするアクセス・サーバーとアクセス・サーバーの両方が伝える3Purgeをバッファリングする、データは4-127 Future UseのためのAvailableをバッファリングします。
Clark Experimental [Page 11] RFC 2217 Telnet Com Port Control Option October 1997
クラーク実験的な[11ページ]RFC2217telnet Comはオプション1997年10月にコントロールを移植します。
4. Notification of Com port and Modem Line Changes
4. ComポートとModem線Changesの通知
The access server can send these commands to the client any time and multiple times throughout the Telnet session. The access server should send the appropriate command to the client as soon as the com port or modem line changes occurs. The client does not issue a response to these commands.
アクセス・サーバーはTelnetセッションの間中ときのいつでも、そして複数の回これらのコマンドをクライアントに送ることができます。 ポートかモデム回線が変えるcomが現れるとすぐに、アクセス・サーバーは適切なコマンドをクライアントに送るべきです。 クライアントはこれらのコマンドへの応答を発行しません。
IAC SB COM-PORT-OPTION NOTIFY-LINESTATE <value> IAC SE
The value is one octet (byte). The value is a bit level
composition made up from the value table below. Multiple bit
values may be set in a single transmission. The values are based
on the most popular UART (com port control chip) in use [1].
IAC SB COM-PORT-OPTION NOTIFY-LINESTATE<は>IAC SEを評価します。値は1つの八重奏(バイト)です。 値は以下に値のテーブルから作られた少し平らな構成です。 複数のビット、値はただ一つのトランスミッションで設定されるかもしれません。 値は使用[1]で最もポピュラーなUART(comポート制御チップ)に基づいています。
Bit Position Value Meaning
7 128 Time-out Error
6 64 Transfer Shift Register Empty
5 32 Transfer Holding Register Empty
4 16 Break-detect Error
3 8 Framing Error
2 4 Parity Error
1 2 Overrun Error
0 1 Data Ready
空のビット位置値の意味7 128タイムアウト誤り6 64の5 32転送把持転送シフトレジスタレジスタ空の4 16は準備ができていた状態で誤り3 8縁どり誤り2 4パリティエラー1 2超過誤り0 1データを中断していて検出します。
Discussion: The LINESTATE is the line state of the UART on
the access server.
議論: LINESTATEはアクセス・サーバーのUARTの系列州です。
IAC SB COM-PORT-OPTION NOTIFY-MODEMSTATE <value> IAC SE
The value is one octet (byte). The value is a bit level
composition made up from the value table below. Multiple bit
values may be set in a single transmission. The values are based
on the most popular UART (com port control chip) in use [1].
IAC SB COM-PORT-OPTION NOTIFY-MODEMSTATE<は>IAC SEを評価します。値は1つの八重奏(バイト)です。 値は以下に値のテーブルから作られた少し平らな構成です。 複数のビット、値はただ一つのトランスミッションで設定されるかもしれません。 値は使用[1]で最もポピュラーなUART(comポート制御チップ)に基づいています。
Bit Position Value Meaning
7 128 Receive Line Signal Detect
(also known as Carrier Detect)
6 64 Ring Indicator
5 32 Data-Set-Ready Signal State
4 16 Clear-To-Send Signal State
3 8 Delta Receive Line Signal Detect
2 4 Trailing-edge Ring Detector
1 2 Delta Data-Set-Ready
0 1 Delta Clear-To-Send
発信するDataが準備ができていた状態でセットしている噛み付いているPosition Value Meaning7 128Receive線Signal Detect(また、Carrier Detectとして、知られている)6 64Ring Indicator5 32Dataが準備ができていた状態でセットしているSignal州4 16発信するClear Signal州3 8デルタReceive線Signal Detect2 4Trailing-縁のRing Detector1 2デルタ0 1デルタClear
Clark Experimental [Page 12] RFC 2217 Telnet Com Port Control Option October 1997
クラーク実験的な[12ページ]RFC2217telnet Comはオプション1997年10月にコントロールを移植します。
5. Flow Control
5. フロー制御
The client and/or access server can send these commands any time and multiple times throughout the Telnet session.
クライアント、そして/または、アクセス・サーバーはTelnetセッションの間中ときのいつでも、そして複数の回これらのコマンドを送ることができます。
IAC SB COM-PORT-OPTION FLOWCONTROL-SUSPEND IAC SE
The sender of this command is requesting that the receiver
suspend transmission of both data and commands until the
FLOWCONTROL-RESUME is transmitted by the sender.
このコマンドの送付者のIAC SB COM-PORT-OPTION FLOWCONTROL-SUSPEND IAC SEは、FLOWCONTROL-RESUMEが送付者によって伝えられるまで受信機がデータとコマンドの両方のトランスミッションを中断させるよう要求しています。
IAC SB COM-PORT-OPTION FLOWCONTROL-RESUME IAC SE
The sender of this command is requesting that the receiver resume
transmission of both data and commands.
このコマンドの送付者のIAC SB COM-PORT-OPTION FLOWCONTROL-RESUME IAC SEは、受信機がデータとコマンドの両方のトランスミッションを再開するよう要求しています。
Discussion: Established Telnet sessions are initially in a
resume state between the client and the access server
and the access server and the client. There is no
need to send the resume command during session
initialization.
議論: 確立したTelnetセッションが初めはクライアントと、アクセス・サーバーと、アクセス・サーバーとクライアントの間の履歴書状態にあります。 セッション初期化の間に再開コマンドを送る必要は全くありません。
Discussion: Multiple concurrent suspend commands may be sent.
Secondary suspend commands can be ignored.
Transmission will resume with the sending of a single
resume command.
議論: 複数の同時発生の中断コマンドを送るかもしれません。 セカンダリ中断コマンドを無視できます。 トランスミッションはただ一つの再開コマンドの発信で再開するでしょう。
Discussion: The flow control option is designed to handle client
to access server flow control for the Telnet session.
This option has been added in deference to RFC 1372:
Telnet Remote Flow Control Option [2]. RFC 1372 uses
a simple character XON/XOFF technology to implement
flow control. This can lead to two problems. First,
the flow control characters may be valid data values.
Second, the flow control characters may be used for
end to end flow control (client application to remote
dial up service).
議論: フロー制御オプションは、Telnetセッションのためのサーバフロー制御にアクセスするためにクライアントを扱うように設計されています。 このオプションはRFC1372を重んじて加えられます: telnetのリモートフロー制御オプション[2]。 RFC1372はフロー制御を実装する簡単なキャラクタXON/XOFF技術を使用します。 これは2つの問題最初に、キャラクタが有効データが値であったならそうするかもしれないフロー制御に通じることができます。 2番目に、終わりがフロー制御(リモートダイヤルアップサービスへのクライアント適用)を終わらせるのにフロー制御キャラクタは使用されるかもしれません。
6. Security Considerations
6. セキュリティ問題
There are two security issues to discuss; authentication and resetting resources.
議論する2つの安全保障問題があります。 認証とリセットリソース。
Authentication can follow either the Kerberos authentication protocol established in RFC 1411 [3] or the SPX authentication protocol established in RFC 1412 [4].
認証はRFC1411[3]に確立されたケルベロス認証プロトコルかRFC1412[4]に確立されたSPX認証プロトコルのどちらかに従うことができます。
Once the Telnet session between the client and the access server has been terminated, the access server should ensure the connection to the remote service is disconnected and the com port geometry (baud
クライアントとアクセス・サーバーとのTelnetセッションがいったん終えられると、アクセス・サーバーが、リモートサービスとの接続が切断されてcomポート幾何学であることを確実にするべきである、(ボー
Clark Experimental [Page 13] RFC 2217 Telnet Com Port Control Option October 1997
クラーク実験的な[13ページ]RFC2217telnet Comはオプション1997年10月にコントロールを移植します。
rate, data size, stop bits, parity, and flow control) is reset to a factory or administrator defined configuration. This ensures the com port is in a known state and ready to receive the next client session. This will make operations more predicable and avoid problems which might occur from starting a new session with random com port configurations.
レート、データサイズ、ストップビット、同等、およびフロー制御) 工場か管理者の定義された構成にリセットされます。 これは、comポートが知られている状態にあって、次のクライアントセッションを受ける準備ができているのを確実にします。 これは、操作をより断定できるようにして、無作為のcomポート構成との新しいセッションを始めるので起こるかもしれない問題を避けるでしょう。
7. Author's Address
7. 作者のアドレス
Glen Clark, Software Architect Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 96134 USA
クラーク、建築家のシスコシステムズInc.170の西タスマン・Driveサンノゼ、谷間ソフトウェアカリフォルニア96134米国
EMail: glenc@cisco.com WEB: www.cisco.com
メール: glenc@cisco.com ウェブ: www.cisco.com
8. Reference Section
8. 参照部
[1] Joe Campbell. C Programmer's Guide to Serial Communications,
Second Edition. Indianapolis: SAMS Publishing, 1993. 213-224.
[1] ジョー・キャンベル。 シリアル通信、第2版へのCプログラマーズガイド。 インディアナポリス: サムズPublishing、1993。 213-224.
[2] Hedrick, C., and D. Borman, "Telnet Remote Flow Control Option",
RFC 1372, Cray Research, Inc., October 1992.
[2] ヘドリック、C.とD.ボーマン、「telnetのリモートフロー制御オプション」、RFC1372、クレイ・リサーチ、1992年10月。
[3] Borman, D., "Telnet Authentication: Kerberos Version 4",
RFC 1411, Cray Research, Inc., January 1993.
[3] ボーマン、D.、「telnet認証:」 ケルベロスバージョン4インチ、RFC1411、クレイ・リサーチ、1993年1月。
[4] Alagappan, K., "Telnet Authentication: SPX",
RFC 1412, Digital Equipment Corporation, January 1993.
[4]Alagappan、K.、「telnet認証:」 "SPX"、RFC1412、ディジタルイクイップメント社、1993年1月。
[5] D. E. Comer and David Stevens. Internetworking with TCP/IP,
Volume III. Prentice Hall, 1993.
[5] D.E.新来者とデヴィッド・スティーブンス。 TCP/IP、巻IIIがあるインターネットワーキング。 新米のホール、1993。
[6] Andrew Margolis. The FAX Modem Sourcebook. John Wiley & Sons.
1995.
[6] アンドリュー・マーゴーリス。 ファックスモデム底本。 ジョン・ワイリーと息子。 1995.
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