RFC 1660 DRAFT STANDARD NETWORK MANAGEMENT · MIB · PRINTERS
Definitions of Managed Objects for Parallel-printer-like Hardware Devices using SMIv2
SNMP objects for parallel printer ports: their type and the on/off state of five status signals.
RFC EDITOR
Stewart, B., "Definitions of Managed Objects for Parallel-printer-like Hardware Devices using SMIv2", RFC 1660, DOI 10.17487/RFC1660, July 1994, <https://www.rfc-editor.org/info/rfc1660>.
BIBTEX
@misc{rfc1660,
series = {Request for Comments},
number = 1660,
howpublished = {RFC 1660},
publisher = {RFC Editor},
doi = {10.17487/RFC1660},
url = {https://www.rfc-editor.org/info/rfc1660},
author = {B. Stewart},
title = {{Definitions of Managed Objects for Parallel-printer-like Hardware Devices using SMIv2}},
pagetotal = 10,
year = 1994,
month = jul,
} RFC text
Contents
Network Working Group B. Stewart
Request for Comments: 1660 Xyplex, Inc.
Obsoletes: 1318 July 1994
Category: Standards Track
Definitions of Managed Objects for Parallel-printer-like
Hardware Devices using SMIv2
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.
Table of Contents
1. Introduction ............................................... 1
2. The SNMPv2 Network Management Framework .................... 1
2.1 Object Definitions ........................................ 2
3. Overview ................................................... 2
3.1 Relationship to Interface MIB ............................. 2
4. Definitions ................................................ 3
5. Acknowledgements ........................................... 9
6. References ................................................. 9
7. Security Considerations .................................... 10
8. Author's Address ........................................... 10
1. Introduction
This memo defines an extension to the Management Information Base
(MIB) for use with network management protocols in the Internet
community. In particular, it defines objects for the management of
Parallel-printer-like devices.
2. The SNMPv2 Network Management Framework
The SNMPv2 Network Management Framework consists of four major
components. They are:
o RFC 1442 [1] which defines the SMI, the mechanisms used for
describing and naming objects for the purpose of management.
o STD 17, RFC 1213 [2] defines MIB-II, the core set of managed
objects for the Internet suite of protocols.
o RFC 1445 [3] which defines the administrative and other
architectural aspects of the framework.
o RFC 1448 [4] which defines the protocol used for network
access to managed objects.
The Framework permits new objects to be defined for the purpose of
experimentation and evaluation.
2.1. Object Definitions
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)
defined in the SMI. In particular, each object object type is named
by an OBJECT IDENTIFIER, an administratively assigned name. 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 descriptor, to
refer to the object type.
3. Overview
The Parallel-printer-like Hardware Device MIB applies to interface
ports that would most probably support the Character MIB. The most
common example is Centronics-like printer port.
The Parallel-printer-like Hardware Device MIB is mandatory for all
systems that have such a hardware port supporting services managed
through some other MIB.
The Parallel-printer-like Hardware Port MIB includes Centronics-like
and Data-Products-like parallel physical links with a similar set of
control signals.
The MIB contains objects that relate to physical layer connections.
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.
3.1. Relationship to Interface MIB
The Parallel-printer-like MIB is one of many MIBs designed for
layered use as described in the Interface MIB [5]. In most
implementations where it is present, it will be in the lowest
interface sublayer, that is, the Parallel-printer-like MIB represents
the physical layer, providing service to higher layers such as the
Character MIB [6].
Although it is unlikely that a parallel printer port will actually be
used as a network interface, which is the intent of the Interface
MIB, the Parallel-printer-like MIB is closely connected to the
Character MIB, which can share hardware interfaces with network
operation, and relate to the RS-232 MIB [7].
The Interface MIB's ifTestTable and ifRcvAddressTable are not
relevant to the Parallel-printer-like MIB.
The Parallel-printer-like MIB is relevant for ifType values para(34)
and perhaps others.
The Parallel-printer-like MIB requires the conformance groups
ifGeneralGroup, and ifFixedLengthGroup.
Usefulness of error counters in this MIB depends on the octet
counters in ifFixedLengthGroup.
4. Definitions
PARALLEL-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
Counter32, Integer32
FROM SNMPv2-SMI
InterfaceIndex
FROM IF-MIB
transmission
FROM RFC1213-MIB
MODULE-COMPLIANCE, OBJECT-GROUP
FROM SNMPv2-CONF;
para MODULE-IDENTITY
LAST-UPDATED "9405261700Z"
ORGANIZATION "IETF Character MIB Working Group"
CONTACT-INFO
" Bob Stewart
Postal: Xyplex, Inc.
295 Foster Street
Littleton, MA 01460
Tel: 508-952-4816
Fax: 508-952-4887
E-mail: rlstewart@eng.xyplex.com"
DESCRIPTION
"The MIB module for Parallel-printer-like hardware devices."
::= { transmission 34 }
-- Generic Parallel-printer-like information
paraNumber OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
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
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of port entries. The number of entries is
given by the value of paraNumber."
::= { para 2 }
paraPortEntry OBJECT-TYPE
SYNTAX ParaPortEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Status and parameter values for a port."
INDEX { paraPortIndex }
::= { paraPortTable 1 }
ParaPortEntry ::=
SEQUENCE {
paraPortIndex
InterfaceIndex,
paraPortType
INTEGER,
paraPortInSigNumber
Integer32,
paraPortOutSigNumber
Integer32
}
paraPortIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of ifIndex for the port. 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)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The port's hardware type."
::= { paraPortEntry 2 }
paraPortInSigNumber OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
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 and that are useful to observe."
::= { paraPortEntry 3 }
paraPortOutSigNumber OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
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 and that are useful to observe."
::= { paraPortEntry 4 }
-- Parallel-printer-like Input Signal Table
paraInSigTable OBJECT-TYPE
SYNTAX SEQUENCE OF ParaInSigEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of port input control signal entries."
::= { para 3 }
paraInSigEntry OBJECT-TYPE
SYNTAX ParaInSigEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Input control signal status for a hardware port."
INDEX { paraInSigPortIndex, paraInSigName }
::= { paraInSigTable 1 }
ParaInSigEntry ::=
SEQUENCE {
paraInSigPortIndex
InterfaceIndex,
paraInSigName
INTEGER,
paraInSigState
INTEGER,
paraInSigChanges
Counter32
}
paraInSigPortIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS read-only
STATUS current
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) }
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Identification of a hardware signal."
::= { paraInSigEntry 2 }
paraInSigState OBJECT-TYPE
SYNTAX INTEGER { none(1), on(2), off(3) }
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The current signal state."
::= { paraInSigEntry 3 }
paraInSigChanges OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of times the signal has changed from
'on' to 'off' or from 'off' to 'on'."
::= { paraInSigEntry 4 }
-- Output Signal Table
paraOutSigTable OBJECT-TYPE
SYNTAX SEQUENCE OF ParaOutSigEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of port output control signal entries."
::= { para 4 }
paraOutSigEntry OBJECT-TYPE
SYNTAX ParaOutSigEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Output control signal status for a hardware port."
INDEX { paraOutSigPortIndex, paraOutSigName }
::= { paraOutSigTable 1 }
ParaOutSigEntry ::=
SEQUENCE {
paraOutSigPortIndex
InterfaceIndex,
paraOutSigName
INTEGER,
paraOutSigState
INTEGER,
paraOutSigChanges
Counter32
}
paraOutSigPortIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS read-only
STATUS current
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) }
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Identification of a hardware signal."
::= { paraOutSigEntry 2 }
paraOutSigState OBJECT-TYPE
SYNTAX INTEGER { none(1), on(2), off(3) }
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The current signal state."
::= { paraOutSigEntry 3 }
paraOutSigChanges OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of times the signal has changed from
'on' to 'off' or from 'off' to 'on'."
::= { paraOutSigEntry 4 }
-- conformance information
paraConformance OBJECT IDENTIFIER ::= { para 5 }
paraGroups OBJECT IDENTIFIER ::= { paraConformance 1 }
paraCompliances OBJECT IDENTIFIER ::= { paraConformance 2 }
-- compliance statements
paraCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for SNMPv2 entities
which have Parallel-printer-like hardware
interfaces."
MODULE -- this module
MANDATORY-GROUPS { paraGroup }
::= { paraCompliances 1 }
-- units of conformance
paraGroup OBJECT-GROUP
OBJECTS { paraNumber, paraPortIndex, paraPortType,
paraPortInSigNumber, paraPortOutSigNumber,
paraInSigPortIndex, paraInSigName,
paraInSigState, paraInSigChanges,
paraOutSigPortIndex, paraOutSigName,
paraOutSigState, paraOutSigChanges }
STATUS current
DESCRIPTION
"A collection of objects providing information
applicable to all Parallel-printer-like interfaces."
::= { paraGroups 1 }
END
5. Acknowledgements
This memo was produced by the IETF Character MIB Working Group.
6. References
[1] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Structure
of Management Information for version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC 1442, SNMP Research,Inc.,
Hughes LAN Systems, Dover Beach Consulting, Inc., Carnegie Mellon
University, April 1993.
[2] McCloghrie, K., and M. Rose, Editors, "Management Information
Base for Network Management of TCP/IP-based internets: MIB-II",
STD 17, RFC 1213, Hughes LAN Systems, Performance Systems
International, March 1991.
[3] Galvin, J., and K. McCloghrie, "Administrative Model for version
2 of the Simple Network Management Protocol (SNMPv2)", RFC 1445,
Trusted Information Systems, Hughes LAN Systems, April 1993.
[4] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Protocol
Operations for version 2 of the Simple Network Management
Protocol (SNMPv2)", RFC 1448, SNMP Research,Inc., Hughes LAN
Systems, Dover Beach Consulting, Inc., Carnegie Mellon
University, April 1993.
[5] McCloghrie, K., and F. Kastenholz, "Evolution of the Interfaces
Group of MIB-II", RFC 1573, Hughes LAN Systems, FTP Software,
January 1994.
[6] Stewart, B., "Definitions of Managed Objects for Character Stream
Devices using SMIv2", RFC 1658, Xyplex, Inc., July 1994.
[7] Stewart, B., "Definitions of Managed Objects for RS-232-like
Devices using SMIv2", RFC 1659, Xyplex, Inc., July 1994.
7. Security Considerations
Security issues are not discussed in this memo.
8. Author's Address
Bob Stewart
Xyplex, Inc.
295 Foster Street
Littleton, MA 01460
Phone: 508-952-4816
Fax: 508-952-4887
EMail: rlstewart@eng.xyplex.com
AI ELI5
On this page
PROBLEMDevices with parallel printer ports had no standard SNMP objects for describing those ports or watching their control signals.
MECHANISMThe RFC defines an SMIv2 MIB module, para, with a port table and input and output signal tables for Centronics-like and Data-Products-like ports.
STATUS TODAYIt is a small Draft Standard that obsoletes RFC 1318. It covers the physical layer only and has no read-write objects.
§1What the MIB Covers
RFC 1660 defines an extension to the Management Information Base (MIB) for managing Parallel-printer-like hardware devices. It obsoletes RFC 1318 and is a companion to RFC 1659, the RS-232-like MIB, from the same author.
The MIB applies to interface ports that would most probably support the Character MIB. The most common example is a Centronics-like printer port; Data-Products-like parallel links with a similar set of control signals are included. It is mandatory for all systems that have such a hardware port supporting services managed through some other MIB.
It is a short list of gauges for the plug that connects a printer to a computer, and every machine with such a plug has to offer them.
§2The SNMPv2 Framework Behind It
The module is written for the SNMPv2 Network Management Framework: RFC 1442 defines the SMI used to describe and name objects, STD 17 (RFC 1213) defines MIB-II, RFC 1445 covers administrative and architectural aspects, and RFC 1448 defines the protocol for access to managed objects.
Objects are named by an OBJECT IDENTIFIER and defined with the subset of ASN.1 allowed by the SMI. This module is placed at transmission 34.
Each gauge has its own unique name in a big shared directory, so a manager can ask for it by name.
§3Layering and the Interface MIB
The MIB is designed for layered use as described in the Interface MIB (RFC 1573). It normally sits in the lowest interface sublayer, the physical layer, serving higher layers such as the Character MIB (RFC 1658).
The RFC admits it is unlikely that a parallel printer port will actually be used as a network interface, which is the intent of the Interface MIB. The MIB is still tied to the Character MIB, which can share hardware interfaces with network operation, and relates to the RS-232 MIB (RFC 1659).
It is relevant for the ifType value para(34) and perhaps others, and requires the conformance groups ifGeneralGroup and ifFixedLengthGroup. The Interface MIB's ifTestTable and ifRcvAddressTable are not relevant.
This MIB describes only the plug and wire at the bottom. Other MIBs describe what is done with the data on top of it.
§4The Tables
The MIB has one base object, paraNumber (the number of ports regardless of state), and three tables.
paraPortTable: one row per port, holding the port index (the same value asifIndex), the hardware type (other,centronicsordataproducts), and the number of input and output signals the port exposes.paraInSigTable: one row per port and input signal.paraOutSigTable: one row per port and output signal.
The signal tables contain entries only for signals the software can detect (input) or assert (output) and that are useful to observe. All objects in the module are read-only.
One table lists the printer plugs, and two more list the lights that come in and go out of each plug.
- para transmission 34
- paraNumber number of ports
- paraPortTable ports
- paraInSigTable input signals
- paraOutSigTable output signals
- paraConformance groups and compliance
§5Signals
Each signal row is identified by a port and a signal name. The names are the same for input and output: power, online, busy, paperout and fault. A row reports the state (none, on or off) and a counter of how many times the signal has changed from on to off or from off to on.
A manager can therefore see not just whether a printer line is currently busy or reports a fault, but how often it has changed.
Each light is on or off, and the table also keeps a count of how many times it has flipped.
§6Compliance and Security
The compliance statement makes a single group, paraGroup, mandatory for SNMPv2 entities that have Parallel-printer-like hardware interfaces. That group holds all thirteen objects of the module.
The Security Considerations section says only that security issues are not discussed in the memo.
If a machine has a printer plug, it must offer all the gauges. The RFC says nothing about security.
§7References
[1]RFC 1442Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Structure of Management Information for version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1442, April 1993.April 1993[2]RFC 1213McCloghrie, K., and M. Rose, Editors, "Management Information Base for Network Management of TCP/IP-based internets: MIB-II", STD 17, RFC 1213, March 1991.March 1991[3]RFC 1445Galvin, J., and K. McCloghrie, "Administrative Model for version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1445, April 1993.April 1993[4]RFC 1448Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Protocol Operations for version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1448, April 1993.April 1993[5]RFC 1573McCloghrie, K., and F. Kastenholz, "Evolution of the Interfaces Group of MIB-II", RFC 1573, January 1994.January 1994[6]RFC 1658Stewart, B., "Definitions of Managed Objects for Character Stream Devices using SMIv2", RFC 1658, July 1994.July 1994[7]RFC 1659Stewart, B., "Definitions of Managed Objects for RS-232-like Devices using SMIv2", RFC 1659, July 1994.July 1994