HEMS variable definitions (RFC1024)
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
C. Partridge: AUTHOR [+2]
notions that are frequently used in other definitions.
Network Working Group C.Partridge
Request For Comment: 1024 BBN/NNSC
HEMS VARIABLE DEFINITIONS
STATUS OF THIS MEMO
This memo assigns instruction codes, defines object formats and
object semantics for use with the High-Level Monitoring and Control
Language, defined in RFC-1023.
This memo is provisional and the definitions are subject to change.
Readers should confirm that they have the most recent version of the
The authors assume a working knowledge of the ISO data encoding
standard, ASN.1, and a general understanding of the IP protocol
Distribution of this memo is unlimited.
In other memos [RFC-1021, RFC-1022] the authors have described a
general system for monitoring and controlling network entities; this
system is called the High-Level Entity Management System (HEMS).
This system permits applications to read and write values in remote
entities which support a simple query processor.
In this memo we standardize the language instruction codes, the
objects which can be read or written, and the meanings of any
constants stored in the objects. There are three parts to this
standardization: (1) the assignment of an ASN.1 tag to each value,
(2) the definition of the external representation of the value (e.g.,
INTEGER, OCTETSTRING, etc.), and (3) the definition of the meaning,
or semantics of a value (e.g., what types of packets a particular
packet counter actually tracks).
This definition is provisional, and the authors hope that it will be
expanded and improved as the community becomes more experienced with
HEMS. Readers with suggestions for additional object definitions, or
improved definitions are encouraged to contact the authors.
All HEMS values are conveyed between applications and entities using
the High-Level Entity Management Protocol (HEMP) specified in RFC-
1022. All values specified in this memo are passed in the data
sections of HEMP messages. For all message types, the data section
is a SEQUENCE of objects. For requests, these objects are operations
and their operands. Replies contain a sequence of objects retrieved
by a request. Events contain an initial event object followed by an
optional number of objects related to the event.
Messages conforming to this memo should set the link field in the
HEMP CommonHeader to 1, to indicate version 1 of HEMS. The
resourceId field should be set to NULL.
CONTROL LANGUAGE INSTRUCTIONS
The HEMS Monitoring and Control Language defines a suite of
operations which the query processor must be able to perform. These
operations and their operands are ASN.1 objects which a...