Network Working Group B. Stewart
Request for Comments: 1658 Xyplex, Inc.
Obsoletes: 1316 July 1994
Category: Standards Track
Definitions of Managed Objects for Character Stream Devices
using SMIv2
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Table of Contents
1. Introduction ................................................ 2
2. The SNMPv2 Network Management Framework ..................... 2
2.1 Object Definitions ......................................... 3
3. Overview .................................................... 3
3.1 Relationship to Interface MIB .............................. 4
4. Definitions ................................................. 4
5. Acknowledgements ............................................ 17
6. References .................................................. 17
7. Security Considerations ..................................... 18
8. Author's Address ............................................ 18
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
character stream 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.
Stewart [Page 1]
RFC 1658 Character MIB July 1994 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 Character MIB applies to ports that carry a character stream, whether physical or virtual, serial or parallel, synchronous or asynchronous. The most common example of a character stream device is a hardware terminal port with an RS-232 interface. Another common hardware example is a parallel printer port, say with a Centronics interface. The concept also includes virtual terminal ports, such as a software connection point for a remote console. The Character MIB is mandatory for all systems that offer character stream ports. This includes, for example, terminal servers, general-purpose time-sharing hosts, and even such systems as a bridge with a (virtual) console port. It may or may not include character ports that do not support network sessions, depending on the system's needs. The Character MIB's central abstraction is a port. Physical ports have a one-to-one correspondence with hardware ports. Virtual ports are software entities analogous to physical ports, but with no hardware connector. Each port supports one or more sessions. A session represents a virtual connection that carries characters between the port and some partner. Sessions typically operate over a stack of network protocols. A typical session, for example, uses Telnet over TCP. Stewart [Page 2]
RFC 1658 Character MIB July 1994 The MIB comprises one base object and two tables, detailed in the following sections. The tables contain objects for ports and sessions. The MIB intentionally contains no distinction between what is often called permanent and operational or volatile data bases. For the purposes of this MIB, handling of such distinctions is implementation specific. 3.1. Relationship to Interface MIB The Character MIB does not relate directly to the Interface MIB [1], since it is not intrinsically a network interface. On the other hand, in most implementations where it is present, it will be above a physical sublayer interface, such as the RS-232-like [2] or Parallel-printer-like [3] MIBs. Such physical interfaces typically are represented by a row in the interface table (ifTable), identified by a value of ifIndex. 4. Definitions CHARACTER-MIB DEFINITIONS ::= BEGIN IMPORTS MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE, Counter32, Integer32, Gauge32, TimeTicks FROM SNMPv2-SMI AutonomousType, InstancePointer FROM SNMPv2-TC InterfaceIndex FROM IF-MIB transmission, mib-2 FROM RFC1213-MIB MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF; char 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 Stewart [Page 3]
RFC 1658 Character MIB July 1994 E-mail: rlstewart@eng.xyplex.com" DESCRIPTION "The MIB module for character stream devices." ::= { mib-2 19 } PortIndex ::= TEXTUAL-CONVENTION DISPLAY-HINT "d" STATUS current DESCRIPTION "A unique value, greater than zero, for each character port in the managed system. It is recommended that values are assigned contiguously starting from 1. The value for each interface sub- layer must remain constant at least from one re- initialization of the entity's network management system to the next re-initialization. In a system where the character ports are attached to hardware represented by an ifIndex, it is conventional, but not required, to make the character port index equal to the corresponding ifIndex." SYNTAX Integer32 -- Generic Character information charNumber OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of entries in charPortTable, regardless of their current state." ::= { char 1 } -- the Character Port table charPortTable OBJECT-TYPE SYNTAX SEQUENCE OF CharPortEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of port entries. The number of entries is given by the value of charNumber." ::= { char 2 } Stewart [Page 4]
RFC 1658 Character MIB July 1994 charPortEntry OBJECT-TYPE SYNTAX CharPortEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Status and parameter values for a character port." INDEX { charPortIndex } ::= { charPortTable 1 } CharPortEntry ::= SEQUENCE { charPortIndex PortIndex, charPortName DisplayString, charPortType INTEGER, charPortHardware AutonomousType, charPortReset INTEGER, charPortAdminStatus INTEGER, charPortOperStatus INTEGER, charPortLastChange TimeTicks, charPortInFlowType INTEGER, charPortOutFlowType INTEGER, charPortInFlowState INTEGER, charPortOutFlowState INTEGER, charPortInCharacters Counter32, charPortOutCharacters Counter32, charPortAdminOrigin INTEGER, charPortSessionMaximum INTEGER, charPortSessionNumber Gauge32, charPortSessionIndex INTEGER, charPortInFlowTypes Stewart [Page 5]
RFC 1658 Character MIB July 1994 OCTET STRING, charPortOutFlowTypes OCTET STRING, charPortLowerIfIndex InterfaceIndex } charPortIndex OBJECT-TYPE SYNTAX PortIndex MAX-ACCESS read-only STATUS current DESCRIPTION "A unique value for each character port, perhaps corresponding to the same value of ifIndex when the character port is associated with a hardware port represented by an ifIndex." ::= { charPortEntry 1 } charPortName OBJECT-TYPE SYNTAX DisplayString (SIZE (0..32)) MAX-ACCESS read-write STATUS current DESCRIPTION "An administratively assigned name for the port, typically with some local significance." ::= { charPortEntry 2 } charPortType OBJECT-TYPE SYNTAX INTEGER { physical(1), virtual(2) } MAX-ACCESS read-only STATUS current DESCRIPTION "The port's type, 'physical' if the port represents an external hardware connector, 'virtual' if it does not." ::= { charPortEntry 3 } charPortHardware OBJECT-TYPE SYNTAX AutonomousType MAX-ACCESS read-only STATUS current DESCRIPTION "A reference to hardware MIB definitions specific to a physical port's external connector. For example, if the connector is RS-232, then the value of this object refers to a MIB sub-tree defining objects specific to RS-232. If an agent is not configured to have such values, the agent returns the object Stewart [Page 6]
RFC 1658 Character MIB July 1994 identifier: nullHardware OBJECT IDENTIFIER ::= { 0 0 } " ::= { charPortEntry 4 } charPortReset OBJECT-TYPE SYNTAX INTEGER { ready(1), execute(2) } MAX-ACCESS read-write STATUS current DESCRIPTION "A control to force the port into a clean, initial state, both hardware and software, disconnecting all the port's existing sessions. In response to a get-request or get-next-request, the agent always returns 'ready' as the value. Setting the value to 'execute' causes a reset." ::= { charPortEntry 5 } charPortAdminStatus OBJECT-TYPE SYNTAX INTEGER { enabled(1), disabled(2), off(3), maintenance(4) } MAX-ACCESS read-write STATUS current DESCRIPTION "The port's desired state, independent of flow control. 'enabled' indicates that the port is allowed to pass characters and form new sessions. 'disabled' indicates that the port is allowed to pass characters but not form new sessions. 'off' indicates that the port is not allowed to pass characters or have any sessions. 'maintenance' indicates a maintenance mode, exclusive of normal operation, such as running a test. 'enabled' corresponds to ifAdminStatus 'up'. 'disabled' and 'off' correspond to ifAdminStatus 'down'. 'maintenance' corresponds to ifAdminStatus 'test'." ::= { charPortEntry 6 } charPortOperStatus OBJECT-TYPE SYNTAX INTEGER { up(1), down(2), maintenance(3), absent(4), active(5) } MAX-ACCESS read-only STATUS current DESCRIPTION "The port's actual, operational state, independent Stewart [Page 7]
RFC 1658 Character MIB July 1994 of flow control. 'up' indicates able to function normally. 'down' indicates inability to function for administrative or operational reasons. 'maintenance' indicates a maintenance mode, exclusive of normal operation, such as running a test. 'absent' indicates that port hardware is not present. 'active' indicates up with a user present (e.g. logged in). 'up' and 'active' correspond to ifOperStatus 'up'. 'down' and 'absent' correspond to ifOperStatus 'down'. 'maintenance' corresponds to ifOperStatus 'test'." ::= { charPortEntry 7 } charPortLastChange OBJECT-TYPE SYNTAX TimeTicks MAX-ACCESS read-only STATUS current DESCRIPTION "The value of sysUpTime at the time the port entered its current operational state. If the current state was entered prior to the last reinitialization of the local network management subsystem, then this object contains a zero value." ::= { charPortEntry 8 } -- charPortInFlowType is deprecated in favor of -- charPortInFlowTypes charPortInFlowType OBJECT-TYPE SYNTAX INTEGER { none(1), xonXoff(2), hardware(3), ctsRts(4), dsrDtr(5) } MAX-ACCESS read-write STATUS deprecated DESCRIPTION "The port's type of input flow control. 'none' indicates no flow control at this level or below. 'xonXoff' indicates software flow control by recognizing XON and XOFF characters. 'hardware' indicates flow control delegated to the lower level, for example a parallel port. 'ctsRts' and 'dsrDtr' are specific to RS-232-like ports. Although not architecturally pure, they are included here for simplicity's sake." ::= { charPortEntry 9 } Stewart [Page 8]
RFC 1658 Character MIB July 1994 -- charPortOutFlowType is deprecated in favor of -- charPortOutFlowTypes charPortOutFlowType OBJECT-TYPE SYNTAX INTEGER { none(1), xonXoff(2), hardware(3), ctsRts(4), dsrDtr(5) } MAX-ACCESS read-write STATUS deprecated DESCRIPTION "The port's type of output flow control. 'none' indicates no flow control at this level or below. 'xonXoff' indicates software flow control by recognizing XON and XOFF characters. 'hardware' indicates flow control delegated to the lower level, for example a parallel port. 'ctsRts' and 'dsrDtr' are specific to RS-232-like ports. Although not architecturally pure, they are included here for simplicy's sake." ::= { charPortEntry 10 } charPortInFlowState OBJECT-TYPE SYNTAX INTEGER { none(1), unknown(2), stop(3), go(4) } MAX-ACCESS read-only STATUS current DESCRIPTION "The current operational state of input flow control on the port. 'none' indicates not applicable. 'unknown' indicates this level does not know. 'stop' indicates flow not allowed. 'go' indicates flow allowed." ::= { charPortEntry 11 } charPortOutFlowState OBJECT-TYPE SYNTAX INTEGER { none(1), unknown(2), stop(3), go(4) } MAX-ACCESS read-only STATUS current DESCRIPTION "The current operational state of output flow control on the port. 'none' indicates not applicable. 'unknown' indicates this level does not know. 'stop' indicates flow not allowed. 'go' indicates flow allowed." ::= { charPortEntry 12 } charPortInCharacters OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only Stewart [Page 9]
RFC 1658 Character MIB July 1994 STATUS current DESCRIPTION "Total number of characters detected as input from the port since system re-initialization and while the port operational state was 'up', 'active', or 'maintenance', including, for example, framing, flow control (i.e. XON and XOFF), each occurrence of a BREAK condition, locally-processed input, and input sent to all sessions." ::= { charPortEntry 13 } charPortOutCharacters OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Total number of characters detected as output to the port since system re-initialization and while the port operational state was 'up', 'active', or 'maintenance', including, for example, framing, flow control (i.e. XON and XOFF), each occurrence of a BREAK condition, locally-created output, and output received from all sessions." ::= { charPortEntry 14 } charPortAdminOrigin OBJECT-TYPE SYNTAX INTEGER { dynamic(1), network(2), local(3), none(4) } MAX-ACCESS read-write STATUS current DESCRIPTION "The administratively allowed origin for establishing session on the port. 'dynamic' allows 'network' or 'local' session establishment. 'none' disallows session establishment." ::= { charPortEntry 15 } charPortSessionMaximum OBJECT-TYPE SYNTAX INTEGER (-1..2147483647) MAX-ACCESS read-write STATUS current DESCRIPTION "The maximum number of concurrent sessions allowed on the port. A value of -1 indicates no maximum. Setting the maximum to less than the current number of sessions has unspecified results." ::= { charPortEntry 16 } Stewart [Page 10]
RFC 1658 Character MIB July 1994 charPortSessionNumber OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of open sessions on the port that are in the connecting, connected, or disconnecting state." ::= { charPortEntry 17 } charPortSessionIndex OBJECT-TYPE SYNTAX INTEGER (0..2147483647) MAX-ACCESS read-only STATUS current DESCRIPTION "The value of charSessIndex for the port's first or only active session. If the port has no active session, the agent returns the value zero." ::= { charPortEntry 18 } charPortInFlowTypes OBJECT-TYPE SYNTAX OCTET STRING (SIZE (1)) MAX-ACCESS read-write STATUS current DESCRIPTION "The port's types of input flow control at the software level. Hardware-level flow control is independently controlled by the appropriate hardware-level MIB. A value of zero indicates no flow control. Depending on the specific implementation, any or all combinations of flow control may be chosen by adding the values: 128 xonXoff, recognizing XON and XOFF characters 64 enqHost, ENQ/ACK to allow input to host 32 enqTerm, ACK to allow output to port " ::= { charPortEntry 19 } charPortOutFlowTypes OBJECT-TYPE SYNTAX OCTET STRING (SIZE (1)) MAX-ACCESS read-write STATUS current DESCRIPTION "The port's types of output flow control at the software level. Hardware-level flow control is independently controlled by the appropriate Stewart [Page 11]
RFC 1658 Character MIB July 1994 hardware-level MIB. A value of zero indicates no flow control. Depending on the specific implementation, any or all combinations of flow control may be chosen by adding the values: 128 xonXoff, recognizing XON and XOFF characters 64 enqHost, ENQ/ACK to allow input to host 32 enqTerm, ACK to allow output to port " ::= { charPortEntry 20 } charPortLowerIfIndex OBJECT-TYPE SYNTAX InterfaceIndex MAX-ACCESS read-only STATUS current DESCRIPTION "The ifIndex value of the lower level hardware supporting this character port, zero if none." ::= { charPortEntry 21 } -- the Character Session table charSessTable OBJECT-TYPE SYNTAX SEQUENCE OF CharSessEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of port session entries." ::= { char 3 } charSessEntry OBJECT-TYPE SYNTAX CharSessEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Status and parameter values for a character port session." INDEX { charSessPortIndex, charSessIndex } ::= { charSessTable 1 } CharSessEntry ::= SEQUENCE { charSessPortIndex PortIndex, charSessIndex Stewart [Page 12]
RFC 1658 Character MIB July 1994 INTEGER, charSessKill INTEGER, charSessState INTEGER, charSessProtocol AutonomousType, charSessOperOrigin INTEGER, charSessInCharacters Counter32, charSessOutCharacters Counter32, charSessConnectionId InstancePointer, charSessStartTime TimeTicks } charSessPortIndex OBJECT-TYPE SYNTAX PortIndex MAX-ACCESS read-only STATUS current DESCRIPTION "The value of charPortIndex for the port to which this session belongs." ::= { charSessEntry 1 } charSessIndex OBJECT-TYPE SYNTAX INTEGER (1..2147483647) MAX-ACCESS read-only STATUS current DESCRIPTION "The session index in the context of the port, a non-zero positive integer. Session indexes within a port need not be sequential. Session indexes may be reused for different ports. For example, port 1 and port 3 may both have a session 2 at the same time. Session indexes may have any valid integer value, with any meaning convenient to the agent implementation." ::= { charSessEntry 2 } charSessKill OBJECT-TYPE SYNTAX INTEGER { ready(1), execute(2) } MAX-ACCESS read-write STATUS current DESCRIPTION Stewart [Page 13]
RFC 1658 Character MIB July 1994 "A control to terminate the session. In response to a get-request or get-next-request, the agent always returns 'ready' as the value. Setting the value to 'execute' causes termination." ::= { charSessEntry 3 } charSessState OBJECT-TYPE SYNTAX INTEGER { connecting(1), connected(2), disconnecting(3) } MAX-ACCESS read-only STATUS current DESCRIPTION "The current operational state of the session, disregarding flow control. 'connected' indicates that character data could flow on the network side of session. 'connecting' indicates moving from nonexistent toward 'connected'. 'disconnecting' indicates moving from 'connected' or 'connecting' to nonexistent." ::= { charSessEntry 4 } charSessProtocol OBJECT-TYPE SYNTAX AutonomousType MAX-ACCESS read-only STATUS current DESCRIPTION "The network protocol over which the session is running. Other OBJECT IDENTIFIER values may be defined elsewhere, in association with specific protocols. However, this document assigns those of known interest as of this writing." ::= { charSessEntry 5 } wellKnownProtocols OBJECT IDENTIFIER ::= { char 4 } protocolOther OBJECT IDENTIFIER ::= { wellKnownProtocols 1 } protocolTelnet OBJECT IDENTIFIER ::= { wellKnownProtocols 2 } protocolRlogin OBJECT IDENTIFIER ::= { wellKnownProtocols 3 } protocolLat OBJECT IDENTIFIER ::= { wellKnownProtocols 4 } protocolX29 OBJECT IDENTIFIER ::= { wellKnownProtocols 5 } protocolVtp OBJECT IDENTIFIER ::= { wellKnownProtocols 6 } charSessOperOrigin OBJECT-TYPE SYNTAX INTEGER { unknown(1), network(2), local(3) } MAX-ACCESS read-only STATUS current DESCRIPTION Stewart [Page 14]
RFC 1658 Character MIB July 1994 "The session's source of establishment." ::= { charSessEntry 6 } charSessInCharacters OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "This session's subset of charPortInCharacters." ::= { charSessEntry 7 } charSessOutCharacters OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "This session's subset of charPortOutCharacters." ::= { charSessEntry 8 } charSessConnectionId OBJECT-TYPE SYNTAX InstancePointer MAX-ACCESS read-only STATUS current DESCRIPTION "A reference to additional local MIB information. This should be the highest available related MIB, corresponding to charSessProtocol, such as Telnet. For example, the value for a TCP connection (in the absence of a Telnet MIB) is the object identifier of tcpConnState. If an agent is not configured to have such values, the agent returns the object identifier: nullConnectionId OBJECT IDENTIFIER ::= { 0 0 } " ::= { charSessEntry 9 } charSessStartTime OBJECT-TYPE SYNTAX TimeTicks MAX-ACCESS read-only STATUS current DESCRIPTION "The value of sysUpTime in MIB-2 when the session entered connecting state." ::= { charSessEntry 10 } Stewart [Page 15]
RFC 1658 Character MIB July 1994 -- conformance information charConformance OBJECT IDENTIFIER ::= { char 5 } charGroups OBJECT IDENTIFIER ::= { charConformance 1 } charCompliances OBJECT IDENTIFIER ::= { charConformance 2 } -- compliance statements charCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "The compliance statement for SNMPv2 entities which have Character hardware interfaces." MODULE -- this module MANDATORY-GROUPS { charGroup } ::= { charCompliances 1 } -- units of conformance charGroup OBJECT-GROUP OBJECTS { charNumber, charPortIndex, charPortName, charPortType, charPortHardware, charPortReset, charPortAdminStatus, charPortOperStatus, charPortLastChange, charPortInFlowState, charPortOutFlowState, charPortAdminOrigin, charPortSessionMaximum, charPortInFlowTypes, charPortOutFlowTypes, charPortInCharacters, charPortOutCharacters, charPortSessionNumber, charPortSessionIndex, charPortLowerIfIndex, charSessPortIndex, charSessIndex, charSessKill, charSessState, charSessProtocol, charSessOperOrigin, charSessInCharacters, charSessOutCharacters, charSessConnectionId, charSessStartTime } STATUS current DESCRIPTION "A collection of objects providing information applicable to all Character interfaces." ::= { charGroups 1 } END Stewart [Page 16]
RFC 1658 Character MIB July 1994 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 RS-232-like Hardware Devices using SMIv2", RFC 1659, Xyplex, Inc., July 1994. [7] Stewart, B., "Definitions of Managed Objects for Parallel- printer-like Hardware Devices using SMIv2", RFC 1660, Xyplex, Inc., July 1994. Stewart [Page 17]
RFC 1658 Character MIB 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 Stewart [Page 18]
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