RFC1318
Network Working Group B. Stewart, Editor Request for Comments: 1318 Xyplex, Inc.
April 1992
Definitions of Managed Objects
for Parallel-printer-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.
Contents
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 parallel-printer-like devices.
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.
Objects
Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB.
Objects in the MIB are 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.
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].
Overview
The Parallel-printer-like Hardware Device MIB applies to interface ports that might logically support the Interface MIB, a Transmission MIB, or the Character MIB (most likely the latter). The most common example is a Centronics or Data Products type parallel printer port.
The Parallel-printer-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.
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 Parallel-printer-like MIB is mandatory for all systems that have such a hardware port supporting services managed through some other MIB, for example, the Character MIB.
The Parallel-printer-like 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 Parallel-printer-like MIB includes Centronics, Data Products, and other parallel 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 Power and PaperOut.
The MIB comprises one base object and three tables, detailed
in the following sections. The tables contain objects for ports and input and output control signals.
Definitions
RFC1318-MIB DEFINITIONS ::= BEGIN
IMPORTS
Counter
FROM RFC1155-SMI
transmission
FROM RFC1213-MIB
OBJECT-TYPE
FROM RFC-1212;
-- this is the MIB module for Parallel-printer-like
-- hardware devices
para OBJECT IDENTIFIER ::= { transmission 34 }
-- the generic Parallel-printer-like group
-- Implementation of this group is mandatory for all
-- systems that have Parallel-printer-like hardware
-- ports supporting higher level services such as
-- character streams
paraNumber OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of ports (regardless of their current
state) in the Parallel-printer-like port table."
::= { para 1 }
-- the Parallel-printer-like Port table
paraPortTable OBJECT-TYPE
SYNTAX SEQUENCE OF ParaPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of port entries. The number of entries is
given by the value of paraNumber."
::= { para 2 }
paraPortEntry OBJECT-TYPE
SYNTAX ParaPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Status and parameter values for a port."
INDEX { paraPortIndex }
::= { paraPortTable 1 }
ParaPortEntry ::=
SEQUENCE {
paraPortIndex
INTEGER,
paraPortType
INTEGER,
paraPortInSigNumber
INTEGER,
paraPortOutSigNumber
INTEGER
}
paraPortIndex 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 paraNumber. 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."
::= { paraPortEntry 1 }
paraPortType OBJECT-TYPE
SYNTAX INTEGER {
other(1),
centronics(2),
dataproducts(3)
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The port's hardware type."
::= { paraPortEntry 2 }
paraPortInSigNumber OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of input signals for the port in the
input signal table (paraPortInSigTable). The table
contains entries only for those signals the software
can detect."
::= { paraPortEntry 3 }
paraPortOutSigNumber OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of output signals for the port in the
output signal table (paraPortOutSigTable). The
table contains entries only for those signals the
software can assert."
::= { paraPortEntry 4 }
-- the Input Signal table
paraInSigTable OBJECT-TYPE
SYNTAX SEQUENCE OF ParaInSigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of port input control signal entries."
::= { para 3 }
paraInSigEntry OBJECT-TYPE
SYNTAX ParaInSigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Input control signal status for a hardware port."
INDEX { paraInSigPortIndex, paraInSigName }
::= { paraInSigTable 1 }
ParaInSigEntry ::=
SEQUENCE {
paraInSigPortIndex
INTEGER,
paraInSigName
INTEGER,
paraInSigState
INTEGER,
paraInSigChanges
Counter
}
paraInSigPortIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of paraPortIndex for the port to which
this entry belongs."
::= { paraInSigEntry 1 }
paraInSigName OBJECT-TYPE
SYNTAX INTEGER { power(1), online(2), busy(3),
paperout(4), fault(5) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Identification of a hardware signal."
::= { paraInSigEntry 2 }
paraInSigState OBJECT-TYPE
SYNTAX INTEGER { none(1), on(2), off(3) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current signal state."
::= { paraInSigEntry 3 }
paraInSigChanges 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'."
::= { paraInSigEntry 4 }
-- the Output Signal table
paraOutSigTable OBJECT-TYPE
SYNTAX SEQUENCE OF ParaOutSigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of port output control signal entries."
::= { para 4 }
paraOutSigEntry OBJECT-TYPE
SYNTAX ParaOutSigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Output control signal status for a hardware port."
INDEX { paraOutSigPortIndex, paraOutSigName }
::= { paraOutSigTable 1 }
ParaOutSigEntry ::=
SEQUENCE {
paraOutSigPortIndex
INTEGER,
paraOutSigName
INTEGER,
paraOutSigState
INTEGER,
paraOutSigChanges
Counter
}
paraOutSigPortIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of paraPortIndex for the port to which
this entry belongs."
::= { paraOutSigEntry 1 }
paraOutSigName OBJECT-TYPE
SYNTAX INTEGER { power(1), online(2), busy(3),
paperout(4), fault(5) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Identification of a hardware signal."
::= { paraOutSigEntry 2 }
paraOutSigState OBJECT-TYPE
SYNTAX INTEGER { none(1), on(2), off(3) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current signal state."
::= { paraOutSigEntry 3 }
paraOutSigChanges 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'."
::= { paraOutSigEntry 4 }
END
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 Donald Merritt, BRL David Perkins, 3Com Jim Reinstedler, Ungerman-Bass Marshall Rose, PSI Ron Strich, SSDS Dean Throop, DG Bill Townsend, Xylogics Jesse Walker, DEC David Waitzman, BBN Bill Westfield, cisco
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.
Security Considerations
Security issues are not discussed in this memo.
Author's Address
Bob Stewart Xyplex, Inc. 330 Codman Hill Road Boxborough, MA 01719
Phone: (508) 264-9900 EMail: [email protected]
