HEMS monitoring and control language (RFC1076)
Original Publication Date: 1988-Nov-01
Included in the Prior Art Database: 2019-Feb-15
Internet Society Requests For Comment (RFCs)
G. Trewitt: AUTHOR [+1]
This RFC specifies a query language for monitoring and control of network entities. This RFC supercedes RFC 1023, extending the query language and providing more discussion of the underlying issues. This language is a component of the High-Level Entity Monitoring System (HEMS) described in RFC 1021 and RFC 1022. Readers may wish to consult these RFCs when reading this memo. RFC 1024 contains detailed assignments of numbers and structures used in this system. Portions of RFC 1024 that define query language structures are superceded by definitions in this memo. This memo assumes a knowledge of the ISO data encoding standard, ASN.1.
Network Working Group G. Trewitt Request for Comments: 1076 Stanford University Obsoletes: RFC 1023 C. Partridge BBN/NNSC November 1988
HEMS Monitoring and Control Language
TABLE OF CONTENTS
1. Status of This Memo 1 Introduction 2 2. Overview and Scope 2 3. Overview of Query Processor Operation 4 4. Encoding of Queries and Responses 5 4.1 Notation Used in This Proposal 5 5. Data Organization 6 5.1 Example Data Tree 7 5.2 Arrays 8 6. Components of a Query 9 7. Reply to a Query 10 8. Query Language 12 8.1 Moving Around in the Data Tree 14 8.2 Retrieving Data 15 8.3 Data Attributes 16 8.4 Examining Memory 18 8.5 Control Operations: Modifying the Data Tree 19 8.6 Associative Data Access: Filters 21 8.7 Terminating a Query 26 9. Extending the Set of Values 27 10. Authorization 27 11. Errors 28 I. ASN.1 Descriptions of Query Language Components 29 I.1 Operation Codes 30 I.2 Error Returns 31 I.3 Filters 33 I.4 Attributes 34 I.5 VendorSpecific 36 II. Implementation Hints 36 III. Obtaining a Copy of the ASN.1 Specification 42
1. STATUS OF THIS MEMO
This RFC specifies a query language for monitoring and control of network entities. This RFC supercedes RFC-1023, extending the query language and providing more discussion of the underlying issues.
Trewitt & Partridge [Page 1]
RFC 1076 HEMS Monitoring and Control Language November 1988
This language is a component of the High-Level Entity Monitoring System (HEMS) described in RFC-1021 and RFC-1022. Readers may wish to consult these RFCs when reading this memo. RFC-1024 contains detailed assignments of numbers and structures used in this system. Portions of RFC-1024 that define query language structures are superceded by definitions in this memo. This memo assumes a knowledge of the ISO data encoding standard, ASN.1.
Distribution of this memo is unlimited.
This RFC specifies the design of a general-purpose, yet efficient, monitoring and control language for managing network entities. The data in the entity is modeled as a hierarchy and specific items are named by giving the path from the root of the tree. Most items are read-only, but some can be "set" in order to perform control operations. Both requests and responses are represented using the ISO ASN.1 data encoding rules.
2. OVERVIEW AND SCOPE
The basic model of monitoring and control used in this memo is that a query is sent to a monitored entity and the entity sends back a response. The term query is used in the database sense -- it may request information, modify data, or both. We will use gateway- oriented examples, but it should be understood that this query- response mechanism is applicable to any IP entity.
In particular, there is no notion of an interactive "conversation" as in SMTP [RFC-821] or FTP [RFC-959]. A query is a complete request that stands on its own and elicits a complete response.
In order to design the query language, we had to define a model for the data to be retrieved by the queries, which required some understandin...