Xyplex, Inc.
April 1992
Definitions of Managed Objects for
RS-232-like Hardware Devices
Status of this Memo
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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
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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
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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
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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.
3.1. Format of Definitions
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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
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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 MIBThe 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 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.
5. Definitions
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RFC1317-MIB DEFINITIONS ::= BEGIN
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IMPORTS
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Counter FROM RFC1155-SMI transmission FROM RFC1213-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
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SYNTAX Rs232PortEntry
ACCESS not-accessible
STATUS mandatory DESCRIPTION "Status and parameter values for a port." INDEX { rs232PortIndex } ::= { rs232PortTable 1 }-
Rs232PortEntry ::=
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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
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SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
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
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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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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 ::=
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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 "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 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 ::=
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SEQUENCE {
rs232SyncPortIndex 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
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SYNTAX Counter
ACCESS read-only
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
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SYNTAX SEQUENCE OF Rs232InSigEntry
ACCESS not-accessible
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 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 }-
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 }-
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
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Based on several private MIBs, this document was produced by the Character MIB Working Group:
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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, DGBill Townsend, Xylogics
Jesse Walker, DEC
David Waitzman, BBN
Bill Westfield, cisco
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7. References
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[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.
8. Security Considerations
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Security issues are not discussed in this memo.
9. Author's Address
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Bob Stewart
Xyplex, Inc.
330 Codman Hill Road
Boxborough, MA 01719Phone: (508) 264-9900 EMail: rlstewart@eng.xyplex.com