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IETF RFC 1317
Definitions of Managed Objects for RS-232-like Hardware Devices
Last modified on Thursday, April 16th, 1992
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Network Working Group B. Stewart, Editor
Request for Comments: 1317 Xyplex, Inc.
April 1992
Definitions of Managed Objects for
RS-232-like Hardware Devices
 Status of this Memo
This document specifies an IAB standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "IAB
Official Protocol Standards" for the standardization state and status
of this protocol. Distribution of this memo is unlimited.
1. Abstract
This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols in TCP/IP based internets.
In particular, it defines objects for the management of RS-232-like
devices.
2. The Network Management Framework
The Internet-standard Network Management Framework consists of three
components. They are:
RFC 1155 which defines the SMI, the mechanisms used for describing
and naming objects for the purpose of management. RFC 1212 defines a
more concise description mechanism, which is wholly consistent with
the SMI.
RFC 1156 which defines MIB-I, the core set of managed objects for the
Internet suite of protocols. RFC 1213, defines MIB-II, an evolution
of MIB-I based on implementation experience and new operational
requirements.
RFC 1157 which defines the SNMP, the protocol used for network access
to managed objects.
The Framework permits new objects to be defined for the purpose of
experimentation and evaluation.
3. Objects
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. Objects in the MIB are
Character MIB Working Group PAGE 1 
RFC 1317 RS-232-LIKE MIB April 1992
defined using the subset of Abstract Syntax Notation One (ASN.1) [7]
defined in the SMI. In particular, each object has a name, a syntax,
and an encoding. The name is an object identifier, an
administratively assigned name, which specifies an object type.
The object type together with an object instance serves to uniquely
identify a specific instantiation of the object. For human
convenience, we often use a textual string, termed the OBJECT
DESCRIPTOR, to also refer to the object type.
The syntax of an object type defines the abstract data structure
corresponding to that object type. The ASN.1 language is used for
this purpose. However, the SMI [3] purposely restricts the ASN.1
constructs which may be used. These restrictions are explicitly made
for simplicity.
The encoding of an object type is simply how that object type is
represented using the object type's syntax. Implicitly tied to the
notion of an object type's syntax and encoding is how the object type
is represented when being transmitted on the network.
The SMI specifies the use of the basic encoding rules of ASN.1 [8],
subject to the additional requirements imposed by the SNMP.
3.1. Format of Definitions
Section 5 contains the specification of all object types contained in
this MIB module. The object types are defined using the conventions
defined in the SMI, as amended by the extensions specified in [9,10].
4. Overview
The RS-232-like Hardware Device MIB applies to interface ports that
might logically support the Interface MIB, a Transmission MIB, or the
Character MIB. The most common example is an RS-232 port with modem
signals.
The RS-232-like MIB is one of a set of MIBs designed for
complementary use. At this writing, the set comprises:
Character MIB
PPP MIB
RS-232-like MIB
Parallel-printer-like MIB
The RS-232-like MIB and the Parallel-printer-like MIB represent the
physical layer, providing service to higher layers such as the
Character MIB or PPP MIB. Further MIBs may appear above these.
Character MIB Working Group PAGE 2
RFC 1317 RS-232-LIKE MIB April 1992
The following diagram shows two possible "MIB stacks", each using the
RS-232-like MIB.
.-----------------.
.-----------------. | Standard MIB |
| Telnet MIB | | Interface Group |
|-----------------| |-----------------|
| Character MIB | | PPP MIB |
|-----------------| |-----------------|
| RS-232-like MIB | | RS-232-like MIB |
`-----------------' `-----------------'
The intent of the model is for the physical-level MIBs to represent
the lowest level, regardless of the higher level that may be using
it. In turn, separate higher level MIBs represent specific
applications, such as a terminal (the Character MIB) or a network
connection (the PPP MIB).
The RS-232-like Hardware Device MIB is mandatory for all systems that
have such a hardware port supporting services managed through some
other MIB, for example, the Character MIB or PPP MIB.
The MIB includes multiple similar types of hardware, and as a result
contains objects not applicable to all of those types. Such objects
are in a separate branch of the MIB, which is required when
applicable and otherwise absent.
The RS-232-like Hardware Port MIB includes RS-232, RS-422, RS-423,
V.35, and other asynchronous or synchronous, serial physical links
with a similar set of control signals.
The MIB contains objects that relate to physical layer connections.
Such connections may provide interesting hardware signals (other than
for basic data transfer), such as RNG and DCD. Hardware ports also
have such attributes as speed and bits per character.
Usefulness of error counters in this MIB depends on the presence of
non-error character counts in higher level MIBs.
The MIB comprises one base object and four tables, detailed in the
following sections. The tables contain objects for all ports,
asynchronous ports, and input and output control signals.
Character MIB Working Group PAGE 3
RFC 1317 RS-232-LIKE MIB April 1992
5. Definitions
RFC 1317-MIB DEFINITIONS ::= BEGIN
IMPORTS
Counter
FROM RFC 1155-SMI
transmission
FROM RFC 1213-MIB
OBJECT-TYPE
FROM RFC 1212;
-- this is the MIB module for RS-232-like hardware devices
rs232 OBJECT IDENTIFIER ::= { transmission 33 }
-- the generic RS-232-like group
-- Implementation of this group is mandatory for all
-- systems that have RS-232-like hardware ports
-- supporting higher level services such as character
-- streams or network interfaces
rs232Number OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of ports (regardless of their current
state) in the RS-232-like general port table."
::= { rs232 1 }
-- the RS-232-like general Port table
rs232PortTable OBJECT-TYPE
SYNTAX SEQUENCE OF Rs232PortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of port entries. The number of entries is
given by the value of rs232Number."
::= { rs232 2 }
rs232PortEntry OBJECT-TYPE
SYNTAX Rs232PortEntry
ACCESS not-accessible
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RFC 1317 RS-232-LIKE MIB April 1992
STATUS mandatory
DESCRIPTION
"Status and parameter values for a port."
INDEX { rs232PortIndex }
::= { rs232PortTable 1 }
Rs232PortEntry ::=
SEQUENCE {
rs232PortIndex
INTEGER,
rs232PortType
INTEGER,
rs232PortInSigNumber
INTEGER,
rs232PortOutSigNumber
INTEGER,
rs232PortInSpeed
INTEGER,
rs232PortOutSpeed
INTEGER }
rs232PortIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A unique value for each port. Its value ranges
between 1 and the value of rs232Number. By
convention and if possible, hardware port numbers
map directly to external connectors. The value for
each port must remain constant at least from one
re-initialization of the network management agent to
the next."
::= { rs232PortEntry 1 }
rs232PortType OBJECT-TYPE
SYNTAX INTEGER { other(1), rs232(2), rs422(3),
rs423(4), v35(5) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The port's hardware type."
::= { rs232PortEntry 2 }
rs232PortInSigNumber OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
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RFC 1317 RS-232-LIKE MIB April 1992
DESCRIPTION
"The number of input signals for the port in the
input signal table (rs232PortInSigTable). The table
contains entries only for those signals the software
can detect."
::= { rs232PortEntry 3 }
rs232PortOutSigNumber OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of output signals for the port in the
output signal table (rs232PortOutSigTable). The
table contains entries only for those signals the
software can assert."
::= { rs232PortEntry 4 }
rs232PortInSpeed OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The port's input speed in bits per second."
::= { rs232PortEntry 5 }
rs232PortOutSpeed OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The port's output speed in bits per second."
::= { rs232PortEntry 6 }
-- the RS-232-like Asynchronous Port group
-- Implementation of this group is mandatory if the system
-- has any asynchronous ports. Otherwise it is not
-- present.
rs232AsyncPortTable OBJECT-TYPE
SYNTAX SEQUENCE OF Rs232AsyncPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of asynchronous port entries. The maximum
entry number is given by the value of rs232Number.
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RFC 1317 RS-232-LIKE MIB April 1992
Entries need not exist for synchronous ports."
::= { rs232 3 }
rs232AsyncPortEntry OBJECT-TYPE
SYNTAX Rs232AsyncPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Status and parameter values for an asynchronous
port."
INDEX { rs232AsyncPortIndex }
::= { rs232AsyncPortTable 1 }
Rs232AsyncPortEntry ::=
SEQUENCE {
rs232AsyncPortIndex
INTEGER,
rs232AsyncPortBits
INTEGER,
rs232AsyncPortStopBits
INTEGER,
rs232AsyncPortParity
INTEGER,
rs232AsyncPortAutobaud
INTEGER,
rs232AsyncPortParityErrs
Counter,
rs232AsyncPortFramingErrs
Counter,
rs232AsyncPortOverrunErrs
Counter
}
rs232AsyncPortIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A unique value for each port. Its value is the
same as rs232PortIndex for the port."
::= { rs232AsyncPortEntry 1 }
rs232AsyncPortBits OBJECT-TYPE
SYNTAX INTEGER (5..8)
ACCESS read-write
STATUS mandatory
DESCRIPTION
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RFC 1317 RS-232-LIKE MIB April 1992
"The port's number of bits in a character."
::= { rs232AsyncPortEntry 2 }
rs232AsyncPortStopBits OBJECT-TYPE
SYNTAX INTEGER { one(1), two(2),
one-and-half(3), dynamic(4) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The port's number of stop bits."
::= { rs232AsyncPortEntry 3 }
rs232AsyncPortParity OBJECT-TYPE
SYNTAX INTEGER { none(1), odd(2), even(3),
mark(4), space(5) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The port's sense of a character parity bit."
::= { rs232AsyncPortEntry 4 }
rs232AsyncPortAutobaud OBJECT-TYPE
SYNTAX INTEGER { enabled(1), disabled(2) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"A control for the port's ability to automatically
sense input speed.
When rs232PortAutoBaud is 'enabled', a port may
autobaud to values different from the set values for
speed, parity, and character size. As a result a
network management system may temporarily observe
values different from what was previously set."
::= { rs232AsyncPortEntry 5 }
rs232AsyncPortParityErrs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Total number of characters with a parity error,
input from the port since system re-initialization
and while the port state was 'up' or 'test'."
::= { rs232AsyncPortEntry 6 }
rs232AsyncPortFramingErrs OBJECT-TYPE
SYNTAX Counter
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RFC 1317 RS-232-LIKE MIB April 1992
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Total number of characters with a framing error,
input from the port since system re-initialization
and while the port state was 'up' or 'test'."
::= { rs232AsyncPortEntry 7 }
rs232AsyncPortOverrunErrs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Total number of characters with an overrun error,
input from the port since system re-initialization
and while the port state was 'up' or 'test'."
::= { rs232AsyncPortEntry 8 }
-- the RS-232-like Synchronous Port group
-- Implementation of this group is mandatory if the system
-- has any synchronous ports. Otherwise it is not
-- present.
rs232SyncPortTable OBJECT-TYPE
SYNTAX SEQUENCE OF Rs232SyncPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of synchronous port entries. The maximum
entry number is given by the value of rs232Number.
Entries need not exist for asynchronous ports."
::= { rs232 4 }
rs232SyncPortEntry OBJECT-TYPE
SYNTAX Rs232SyncPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Status and parameter values for a synchronous
port."
INDEX { rs232SyncPortIndex }
::= { rs232SyncPortTable 1 }
Rs232SyncPortEntry ::=
SEQUENCE {
rs232SyncPortIndex
Character MIB Working Group PAGE 9
RFC 1317 RS-232-LIKE MIB April 1992
INTEGER,
rs232SyncPortClockSource
INTEGER,
rs232SyncPortFrameCheckErrs
Counter,
rs232SyncPortTransmitUnderrunErrs
Counter,
rs232SyncPortReceiveOverrunErrs
Counter,
rs232SyncPortInterruptedFrames
Counter,
rs232SyncPortAbortedFrames
Counter
}
rs232SyncPortIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A unique value for each port. Its value is the
same as rs232PortIndex for the port."
::= { rs232SyncPortEntry 1 }
rs232SyncPortClockSource OBJECT-TYPE
SYNTAX INTEGER { internal(1), external(2), split(3) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"Source of the port's bit rate clock. 'split' means
the tranmit clock is internal and the receive clock
is external."
::= { rs232SyncPortEntry 2 }
rs232SyncPortFrameCheckErrs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Total number of frames with an invalid frame check
sequence, input from the port since system
re-initialization and while the port state was 'up'
or 'test'."
::= { rs232SyncPortEntry 3 }
rs232SyncPortTransmitUnderrunErrs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
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RFC 1317 RS-232-LIKE MIB April 1992
STATUS mandatory
DESCRIPTION
"Total number of frames that failed to be
transmitted on the port since system
re-initialization and while the port state was 'up'
or 'test' because data was not available to the
transmitter in time."
::= { rs232SyncPortEntry 4 }
rs232SyncPortReceiveOverrunErrs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Total number of frames that failed to be received
on the port since system re-initialization and while
the port state was 'up' or 'test' because the
receiver did not accept the data in time."
::= { rs232SyncPortEntry 5 }
rs232SyncPortInterruptedFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Total number of frames that failed to be received
or transmitted on the port due to loss of modem
signals since system re-initialization and while the
port state was 'up' or 'test'."
::= { rs232SyncPortEntry 6 }
rs232SyncPortAbortedFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Number of frames aborted on the port due to
receiving an abort sequence since system
re-initialization and while the port state was 'up'
or 'test'."
::= { rs232SyncPortEntry 7 }
-- the Input Signal table
rs232InSigTable OBJECT-TYPE
SYNTAX SEQUENCE OF Rs232InSigEntry
ACCESS not-accessible
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RFC 1317 RS-232-LIKE MIB April 1992
STATUS mandatory
DESCRIPTION
"A list of port input control signal entries."
::= { rs232 5 }
rs232InSigEntry OBJECT-TYPE
SYNTAX Rs232InSigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Input control signal status for a hardware port."
INDEX { rs232InSigPortIndex, rs232InSigName }
::= { rs232InSigTable 1 }
Rs232InSigEntry ::=
SEQUENCE {
rs232InSigPortIndex
INTEGER,
rs232InSigName
INTEGER,
rs232InSigState
INTEGER,
rs232InSigChanges
Counter
}
rs232InSigPortIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of rs232PortIndex for the port to which
this entry belongs."
::= { rs232InSigEntry 1 }
rs232InSigName OBJECT-TYPE
SYNTAX INTEGER { rts(1), cts(2), dsr(3), dtr(4), ri(5),
dcd(6), sq(7), srs(8), srts(9),
scts(10), sdcd(11) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Identification of a hardware signal, as follows:
rts Request to Send
cts Clear to Send
dsr Data Set Ready
dtr Data Terminal Ready
Character MIB Working Group PAGE 12
RFC 1317 RS-232-LIKE MIB April 1992
ri Ring Indicator
dcd Received Line Signal Detector
sq Signal Quality Detector
srs Data Signaling Rate Selector
srts Secondary Request to Send
scts Secondary Clear to Send
sdcd Secondary Received Line Signal Detector
"
REFERENCE
"EIA Standard RS-232-C, August 1969."
::= { rs232InSigEntry 2 }
rs232InSigState OBJECT-TYPE
SYNTAX INTEGER { none(1), on(2), off(3) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current signal state."
::= { rs232InSigEntry 3 }
rs232InSigChanges OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times the signal has changed from
'on' to 'off' or from 'off' to 'on'."
::= { rs232InSigEntry 4 }
-- the Output Signal table
rs232OutSigTable OBJECT-TYPE
SYNTAX SEQUENCE OF Rs232OutSigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of port output control signal entries."
::= { rs232 6 }
rs232OutSigEntry OBJECT-TYPE
SYNTAX Rs232OutSigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Output control signal status for a hardware port."
INDEX { rs232OutSigPortIndex, rs232OutSigName }
::= { rs232OutSigTable 1 }
Character MIB Working Group PAGE 13
RFC 1317 RS-232-LIKE MIB April 1992
Rs232OutSigEntry ::=
SEQUENCE {
rs232OutSigPortIndex
INTEGER,
rs232OutSigName
INTEGER,
rs232OutSigState
INTEGER,
rs232OutSigChanges
Counter
}
rs232OutSigPortIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of rs232PortIndex for the port to which
this entry belongs."
::= { rs232OutSigEntry 1 }
rs232OutSigName OBJECT-TYPE
SYNTAX INTEGER { rts(1), cts(2), dsr(3), dtr(4), ri(5),
dcd(6), sq(7), srs(8), srts(9),
scts(10), sdcd(11) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Identification of a hardware signal, as follows:
rts Request to Send
cts Clear to Send
dsr Data Set Ready
dtr Data Terminal Ready
ri Ring Indicator
dcd Received Line Signal Detector
sq Signal Quality Detector
srs Data Signaling Rate Selector
srts Secondary Request to Send
scts Secondary Clear to Send
sdcd Secondary Received Line Signal Detector
"
REFERENCE
"EIA Standard RS-232-C, August 1969."
::= { rs232OutSigEntry 2 }
Character MIB Working Group PAGE 14
RFC 1317 RS-232-LIKE MIB April 1992
rs232OutSigState OBJECT-TYPE
SYNTAX INTEGER { none(1), on(2), off(3) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current signal state."
::= { rs232OutSigEntry 3 }
rs232OutSigChanges OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times the signal has changed from
'on' to 'off' or from 'off' to 'on'."
::= { rs232OutSigEntry 4 }
END
6. Acknowledgements
Based on several private MIBs, this document was produced by the
Character MIB Working Group:
Anne Ambler, Spider
Charles Bazaar, Emulex
Christopher Bucci, Datability
Anthony Chung, Hughes LAN Systems
George Conant, Xyplex
John Cook, Chipcom
James Davin, MIT-LCS
Shawn Gallagher, DEC
Tom Grant, Xylogics
Frank Huang, Emulex
David Jordan, Emulex
Satish Joshi, SynOptics
Frank Kastenholz, Clearpoint
Ken Key, University of Tennessee
Jim Kinder, Fibercom
Rajeev Kochhar, 3Com
John LoVerso, Xylogics
Keith McCloghrie, Hughes LAN Systems
Donalpd Merritt, BRL
David Perkins, 3Com
Jim Reinstedler, Ungerman-Bass
Marshall Rose, PSI
Ron Strich, SSDS
Dean Throop, DG
Character MIB Working Group PAGE 15
RFC 1317 RS-232-LIKE MIB April 1992
Bill Townsend, Xylogics
Jesse Walker, DEC
David Waitzman, BBN
Bill Westfield, cisco
7. References
[1] Cerf, V., "IAB Recommendations for the Development of Internet
Network Management Standards", RFC 1052, NRI, April 1988.
[2] Cerf, V., "Report of the Second Ad Hoc Network Management Review
Group", RFC 1109, NRI, August 1989.
[3] Rose M., and K. McCloghrie, "Structure and Identification of
Management Information for TCP/IP-based internets", RFC 1155,
Performance Systems International, Hughes LAN Systems, May 1990.
[4] McCloghrie K., and M. Rose, "Management Information Base for
Network Management of TCP/IP-based internets", RFC 1156, Hughes
LAN Systems, Performance Systems International, May 1990.
[5] Case, J., Fedor, M., Schoffstall, M., and J. Davin, Simple
Network Management Protocol", RFC 1157, SNMP Research,
Performance Systems International, Performance Systems
International, MIT Laboratory for Computer Science, May 1990.
[6] McCloghrie K., and M. Rose, Editors, "Management Information Base
for Network Management of TCP/IP-based internets", RFC 1213,
Performance Systems International, March 1991.
[7] Information processing systems - Open Systems Interconnection -
Specification of Abstract Syntax Notation One (ASN.1),
International Organization for Standardization, International
Standard 8824, December 1987.
[8] Information processing systems - Open Systems Interconnection -
Specification of Basic Encoding Rules for Abstract Notation One
(ASN.1), International Organization for Standardization,
International Standard 8825, December 1987.
[9] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions",
RFC 1212, Performance Systems International, Hughes LAN Systems,
March 1991.
[10] Rose, M., Editor, "A Convention for Defining Traps for use with
the SNMP", RFC 1215, Performance Systems International, March
1991.
Character MIB Working Group PAGE 16
RFC 1317 RS-232-LIKE MIB April 1992
8. Security Considerations
Security issues are not discussed in this memo.
9. Author's Address
Bob Stewart
Xyplex, Inc.
330 Codman Hill Road
Boxborough, MA 01719
Phone: (508) 264-9900
EMail: rlstewart@eng.xyplex.com
Character MIB Working Group PAGE 17
Definitions of Managed Objects for RS-232-like Hardware Devices
RFC TOTAL SIZE: 30442 bytes
PUBLICATION DATE: Thursday, April 16th, 1992
LEGAL RIGHTS: The IETF Trust (see BCP 78)
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