Wellfleet Communications, Inc.
F. Baker
Advanced Computer Communications
C. Carvalho
Advanced Computer Communications
April 1992
Management Information Base for Frame Relay DTEs
Status of this Memo
-
This RFC 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.
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 managing Frame Relay.
Table of Contents
-
1. The Network Management Framework ............................ 2 2. Objects ..................................................... 2 2.1 Format of Definitions ...................................... 3 3. Overview .................................................... 3 3.1 Frame Relay Operational Model .............................. 3 3.2 Textual Conventions ........................................ 3 3.3 Structure of MIB ........................................... 3 4. Definitions ................................................. 4 4.1 Data Link Connection Management Interface .................. 4 4.2 Circuit Table .............................................. 9 4.3 Error Table ................................................ 14 5. Acknowledgements ............................................ 17 6. References .................................................. 17 7. Security Considerations...................................... 18 8. Authors' Addresses........................................... 19
1. 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.
2. 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.
2.1. Format of Definitions
-
Section 4 contains 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].
3. Overview
3.1. Frame Relay Operational Model
-
For the purposes of understanding this document, Frame Relay is viewed as a multi-access media, not as a group of point-to-point connections. This model proposes that Frame Relay is a single interface to the network (physical connection) with many destinations or neighbors (virtual connections). This view enables a network manager the ability to group all virtual connections with their corresponding physical connection thereby allowing simpler diagnostics and trouble shooting.
3.2. Textual Conventions
-
Several new data types are introduced as a textual convention in this MIB document. These textual conventions enhance the readability of the specification and can ease comparison with other specifications if appropriate. It should be noted that the introduction of the these textual conventions has no effect on either the syntax nor the semantics of any managed objects. The use of these is merely an artifact of the explanatory method used. Objects defined in terms of one of these methods are always encoded by means of the rules that define the primitive type. Hence, no changes to the SMI or the SNMP are necessary to accommodate these textual conventions which are adopted merely for the convenience of readers and writers in pursuit of the elusive goal of clear, concise, and unambiguous MIB documents.
The new data types are Index and DLCI. Index refers to the range 1..ifNumber, and is used to establish the correspondence between ifEntries and Frame Relay Interfaces. DLCI refers to the range 0..DLCINumber, and is used to refer to the valid Data Link Connection Indices. DLCINumber is, by definition, the largest possible DLCI value possible under the configured Q.922 Address Format.
3.3. Structure of MIB
-
The MIB is composed of three groups, one defining the Data Link Connection Management Interface (DLCMI), one describing the Circuits, and a third describing errors.
During normal operation, Frame Relay virtual circuits will be added, deleted and change availability. The occurrence of such changes is of interest to the network manager and therefore, one trap is defined, intended to be corollary to the SNMP "Link Up" and "Link Down" traps.
4. Definitions
-
-
RFC1315-MIB DEFINITIONS ::= BEGIN
IMPORTS
OBJECT-TYPE FROM RFC-1212 transmission FROM RFC1213-MIB TimeTicks FROM RFC-1155 TRAP-TYPE FROM RFC-1215; -- Frame Relay DTE MIB frame-relay OBJECT IDENTIFIER ::= { transmission 32 } -- -- the range of ifIndex -- Index ::= INTEGER -- 1..ifNumber -- -- the range of a Data Link Connection Identifier -- DLCI ::= INTEGER -- 0..DLCINumber-
-- Data Link Connection Management Interface
-- The variables that configure the DLC Management Interface.
-
frDlcmiTable OBJECT-TYPE
SYNTAX SEQUENCE OF FrDlcmiEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The Parameters for the Data Link Connection Management Interface for the frame relay service on this interface." REFERENCE "Draft American National Standard T1.617-1991, Annex D" ::= { frame-relay 1 }-
-
frDlcmiEntry OBJECT-TYPE
-
SYNTAX FrDlcmiEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The Parameters for a particular Data Link Con- nection Management Interface." INDEX { frDlcmiIfIndex } ::= { frDlcmiTable 1 } FrDlcmiEntry ::= SEQUENCE { frDlcmiIfIndex Index, frDlcmiState INTEGER, frDlcmiAddress INTEGER, frDlcmiAddressLen INTEGER, frDlcmiPollingInterval INTEGER, frDlcmiFullEnquiryInterval INTEGER, frDlcmiErrorThreshold INTEGER, frDlcmiMonitoredEvents INTEGER, frDlcmiMaxSupportedVCs INTEGER, frDlcmiMulticast INTEGER }-
-
frDlcmiIfIndex OBJECT-TYPE
-
SYNTAX Index ACCESS read-only STATUS mandatory DESCRIPTION "The ifIndex value of the corresponding ifEn- try." ::= { frDlcmiEntry 1 }-
-
frDlcmiState OBJECT-TYPE
-
SYNTAX INTEGER { noLmiConfigured (1), lmiRev1 (2), ansiT1-617-D (3), -- ANSI T1.617 Annex D ansiT1-617-B (4) -- ANSI T1.617 Annex B } ACCESS read-write STATUS mandatory DESCRIPTION "This variable states which Data Link Connec- tion Management scheme is active (and by impli- cation, what DLCI it uses) on the Frame Relay interface." REFERENCE "Draft American National Standard T1.617-1991" ::= { frDlcmiEntry 2 }-
-
frDlcmiAddress OBJECT-TYPE
-
SYNTAX INTEGER { q921 (1), -- 13 bit DLCI q922March90 (2), -- 11 bit DLCI q922November90 (3), -- 10 bit DLCI q922 (4) -- Final Standard } ACCESS read-write STATUS mandatory DESCRIPTION "This variable states which address format is in use on the Frame Relay interface." ::= { frDlcmiEntry 3 }-
-
frDlcmiAddressLen OBJECT-TYPE
-
SYNTAX INTEGER { two-octets (2), three-octets (3), four-octets (4) } ACCESS read-write STATUS mandatory DESCRIPTION "This variable states which address length in octets. In the case of Q922 format, the length indicates the entire length of the address in- cluding the control portion." ::= { frDlcmiEntry 4 }-
-
frDlcmiPollingInterval OBJECT-TYPE
-
SYNTAX INTEGER (5..30) ACCESS read-write STATUS mandatory DESCRIPTION "This is the number of seconds between succes- sive status enquiry messages." REFERENCE "Draft American National Standard T1.617-1991, Section D.7 Timer T391." DEFVAL { 10 } ::= { frDlcmiEntry 5 }-
-
frDlcmiFullEnquiryInterval OBJECT-TYPE
-
SYNTAX INTEGER (1..255) ACCESS read-write STATUS mandatory DESCRIPTION "Number of status enquiry intervals that pass before issuance of a full status enquiry mes- sage." REFERENCE "Draft American National Standard T1.617-1991, Section D.7 Counter N391." DEFVAL { 6 } ::= { frDlcmiEntry 6 }-
-
frDlcmiErrorThreshold OBJECT-TYPE
-
SYNTAX INTEGER (1..10) ACCESS read-write STATUS mandatory DESCRIPTION "This is the maximum number of unanswered Status Enquiries the equipment shall accept be- fore declaring the interface down." REFERENCE "Draft American National Standard T1.617-1991, Section D.5.1 Counter N392." DEFVAL { 3 } ::= { frDlcmiEntry 7 }-
-
frDlcmiMonitoredEvents OBJECT-TYPE
-
SYNTAX INTEGER (1..10) ACCESS read-write STATUS mandatory DESCRIPTION "This is the number of status polling intervals over which the error threshold is counted. For example, if within 'MonitoredEvents' number of events the station receives 'ErrorThreshold' number of errors, the interface is marked as down." REFERENCE "Draft American National Standard T1.617-1991, Section D.5.2 Counter N393." DEFVAL { 4 } ::= { frDlcmiEntry 8 }-
-
frDlcmiMaxSupportedVCs OBJECT-TYPE
-
SYNTAX INTEGER ACCESS read-write STATUS mandatory DESCRIPTION "The maximum number of Virtual Circuits allowed for this interface. Usually dictated by the Frame Relay network. In response to a SET, if a value less than zero or higher than the agent's maximal capability is configured, the agent should respond bad- Value" ::= { frDlcmiEntry 9 }-
-
frDlcmiMulticast OBJECT-TYPE
-
SYNTAX INTEGER { nonBroadcast (1), broadcast (2) } ACCESS read-write STATUS mandatory DESCRIPTION "This indicates whether the Frame Relay inter- face is using a multicast service." ::= { frDlcmiEntry 10 }-
-- A Frame Relay service is a multiplexing service. Data
-- Link Connection Identifiers enumerate virtual circuits -- (permanent or dynamic) which are layered onto the underlying -- circuit, represented by ifEntry. Therefore, each of the entries -- in the Standard MIB's Interface Table with an IfType of -- Frame Relay represents a Q.922 interface. Zero or more -- virtual circuits are layered onto this interface and provide -- interconnection with various remote destinations.
-- Each such virtual circuit is represented by an entry in the -- circuit table.
-- Circuit Table
-
-- The table describing the use of the DLCIs attached to
-- each Frame Relay Interface.frCircuitTable OBJECT-TYPE
SYNTAX SEQUENCE OF FrCircuitEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A table containing information about specific Data Link Connection Identifiers and corresponding virtual circuits." ::= { frame-relay 2 }-
-
frCircuitEntry OBJECT-TYPE
-
SYNTAX FrCircuitEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The information regarding a single Data Link Connection Identifier." INDEX { frCircuitIfIndex, frCircuitDlci } ::= { frCircuitTable 1 }-
-
FrCircuitEntry ::=
-
SEQUENCE {
-
frCircuitIfIndex Index, frCircuitDlci DLCI, frCircuitState INTEGER, frCircuitReceivedFECNs Counter, frCircuitReceivedBECNs Counter, frCircuitSentFrames Counter, frCircuitSentOctets Counter, frCircuitReceivedFrames Counter, frCircuitReceivedOctets Counter, frCircuitCreationTime TimeTicks, frCircuitLastTimeChange TimeTicks, frCircuitCommittedBurst INTEGER, frCircuitExcessBurst INTEGER, frCircuitThroughput INTEGER }-
-
frCircuitIfIndex OBJECT-TYPE
-
SYNTAX Index ACCESS read-only STATUS mandatory DESCRIPTION "The ifIndex Value of the ifEntry this virtual circuit is layered onto." ::= { frCircuitEntry 1 }-
-
frCircuitDlci OBJECT-TYPE
-
SYNTAX DLCI ACCESS read-only STATUS mandatory DESCRIPTION "The Data Link Connection Identifier for this virtual circuit." REFERENCE "Draft American National Standard T1.618-1991, Section 3.3.6" ::= { frCircuitEntry 2 }-
-
frCircuitState OBJECT-TYPE
-
SYNTAX INTEGER { invalid (1), active (2), inactive (3) } ACCESS read-write STATUS mandatory DESCRIPTION "Indicates whether the particular virtual cir- cuit is operational. In the absence of a Data Link Connection Management Interface, virtual circuit entries (rows) may be created by set- ting virtual circuit state to 'active', or deleted by changing Circuit state to 'invalid'. Whether or not the row actually disappears is left to the implementation, so this object may actually read as 'invalid' for some arbitrary length of time. It is also legal to set the state of a virtual circuit to 'inactive' to temporarily disable a given circuit." DEFVAL { active } ::= { frCircuitEntry 3 }-
-
frCircuitReceivedFECNs OBJECT-TYPE
-
SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "Number of frames received from the network in- dicating forward congestion since the virtual circuit was created." REFERENCE "Draft American National Standard T1.618-1991, Section 3.3.3" ::= { frCircuitEntry 4 }-
-
frCircuitReceivedBECNs OBJECT-TYPE
-
SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "Number of frames received from the network in- dicating backward congestion since the virtual circuit was created." REFERENCE "Draft American National Standard T1.618-1991, Section 3.3.4" ::= { frCircuitEntry 5 }-
-
frCircuitSentFrames OBJECT-TYPE
-
SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of frames sent from this virtual circuit since it was created." ::= { frCircuitEntry 6 }-
-
frCircuitSentOctets OBJECT-TYPE
-
SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of octets sent from this virtual circuit since it was created." ::= { frCircuitEntry 7 }-
-
frCircuitReceivedFrames OBJECT-TYPE
-
SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "Number of frames received over this virtual circuit since it was created." ::= { frCircuitEntry 8 }-
-
frCircuitReceivedOctets OBJECT-TYPE
-
SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "Number of octets received over this virtual circuit since it was created." ::= { frCircuitEntry 9 }-
-
frCircuitCreationTime OBJECT-TYPE
-
SYNTAX TimeTicks ACCESS read-only STATUS mandatory DESCRIPTION "The value of sysUpTime when the virtual cir- cuit was created, whether by the Data Link Con- nection Management Interface or by a SetRe- quest." ::= { frCircuitEntry 10 }-
-
frCircuitLastTimeChange OBJECT-TYPE
-
SYNTAX TimeTicks ACCESS read-only STATUS mandatory DESCRIPTION "The value of sysUpTime when last there was a change in the virtual circuit state" ::= { frCircuitEntry 11 }-
-
frCircuitCommittedBurst OBJECT-TYPE
-
SYNTAX INTEGER ACCESS read-write STATUS mandatory DESCRIPTION "This variable indicates the maximum amount of data, in bits, that the network agrees to transfer under normal conditions, during the measurement interval." REFERENCE "Draft American National Standard T1.617-1991, Section 6.5.19" DEFVAL { 0 } -- the default indicates no commitment ::= { frCircuitEntry 12 }-
-
frCircuitExcessBurst OBJECT-TYPE
-
SYNTAX INTEGER ACCESS read-write STATUS mandatory DESCRIPTION "This variable indicates the maximum amount of uncommitted data bits that the network will at- -
tempt to deliver over the measurement interval.
-
By default, if not configured when creating the entry, the Excess Information Burst Size is set to the value of ifSpeed." REFERENCE "Draft American National Standard T1.617-1991, Section 6.5.19" ::= { frCircuitEntry 13 }-
-
frCircuitThroughput OBJECT-TYPE
-
SYNTAX INTEGER ACCESS read-write STATUS mandatory DESCRIPTION "Throughput is the average number of 'Frame Re- lay Information Field' bits transferred per second across a user network interface in one direction, measured over the measurement inter- val. If the configured committed burst rate and throughput are both non-zero, the measurement interval T=frCircuitCommittedBurst/frCircuitThroughput. If the configured committed burst rate and throughput are both zero, the measurement in- terval T=frCircuitExcessBurst/ifSpeed." REFERENCE "Draft American National Standard T1.617-1991, Section 6.5.19" DEFVAL {0} -- the default value of Throughput is -- "no commitment". ::= { frCircuitEntry 14 }-
-- Error Table
-- The table describing errors encountered on each Frame
-- Relay Interface.frErrTable OBJECT-TYPE
SYNTAX SEQUENCE OF FrErrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A table containing information about Errors on the Frame Relay interface." ::= { frame-relay 3 }-
-
frErrEntry OBJECT-TYPE
-
SYNTAX FrErrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The error information for a single frame relay interface." INDEX { frErrIfIndex } ::= { frErrTable 1 } FrErrEntry ::= SEQUENCE { frErrIfIndex Index, frErrType INTEGER, frErrData OCTET STRING, frErrTime TimeTicks }-
-
frErrIfIndex OBJECT-TYPE
-
SYNTAX Index ACCESS read-only STATUS mandatory DESCRIPTION "The ifIndex Value of the corresponding ifEn- try." ::= { frErrEntry 1 }-
-
frErrType OBJECT-TYPE
-
SYNTAX INTEGER { unknownError(1), receiveShort(2), receiveLong(3), illegalDLCI(4), unknownDLCI(5), dlcmiProtoErr(6), dlcmiUnknownIE(7), dlcmiSequenceErr(8), dlcmiUnknownRpt(9), noErrorSinceReset(10) } ACCESS read-only STATUS mandatory DESCRIPTION "The type of error that was last seen on this interface." ::= { frErrEntry 2 }-
-
frErrData OBJECT-TYPE
-
SYNTAX OCTET STRING ACCESS read-only STATUS mandatory DESCRIPTION "An octet string containing as much of the er- ror packet as possible. As a minimum, it must contain the Q.922 Address or as much as was delivered. It is desirable to include all in- formation up to the PDU." ::= { frErrEntry 3 }-
-
frErrTime OBJECT-TYPE
-
SYNTAX TimeTicks ACCESS read-only STATUS mandatory DESCRIPTION "The value of sysUpTime at which the error was detected." ::= { frErrEntry 4 }-
-
-- Frame Relay Globals
-
-
frame-relay-globals OBJECT IDENTIFIER ::= { frame-relay 4 }
-
-
-
frTrapState OBJECT-TYPE
-
SYNTAX INTEGER { enabled(1), disabled(2) } ACCESS read-write STATUS mandatory DESCRIPTION "This variable indicates whether the system produces the frDLCIStatusChange trap." DEFVAL { disabled } ::= { frame-relay-globals 1 } -
-- Data Link Connection Management Interface Related Traps
-
-
-
frDLCIStatusChange TRAP-TYPE
-
ENTERPRISE frame-relay VARIABLES { frCircuitIfIndex, frCircuitDlci, frCircuitState } DESCRIPTION "This trap indicates that the indicated Virtual Circuit has changed state. It has either been created or invalidated, or has toggled between the active and inactive states." ::= 1 END -
5. Acknowledgements
-
This document was produced by the IP Over Large Public Data Networks (IPLPDN) Working Group.
The following people provided additional comments and suggestions: Art Berggreen of Advanced Computer Communications, and Jim Philippou of Xyplex Communications.
6. 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.
7. Security Considerations
-
Security issues are not discussed in this memo.
8. Authors' Addresses
-
Caralyn Brown Wellfleet Communications, Inc. 15 Crosby Drive Bedford, Massachusetts 01730 Phone: (617) 275-2400 EMail: cbrown@wellfleet.com Fred Baker Advanced Computer Communications 315 Bollay Drive Sannta Barbara, California 93117 Phone: (805) 685-4455 EMail: fbaker@acc.com Charles Carvalho Advanced Computer Communications 315 Bollay Drive Sannta Barbara, California 93117 Phone: (805) 685-4455 EMail: charles@acc.com