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.
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.
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.
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.
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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.
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.
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
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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 }
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charPortEntry OBJECT-TYPE SYNTAX CharPortEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Status and parameter values for a character port." INDEX { charPortIndex } ::= { charPortTable 1 }
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
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
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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 }
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-- 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 }
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 }
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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
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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 }
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
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"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 }
charSessOperOrigin OBJECT-TYPE SYNTAX INTEGER { unknown(1), network(2), local(3) } MAX-ACCESS read-only STATUS current DESCRIPTION
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"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:
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 }
[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.