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Method for the automated negotiation of SNMP encoding rules

IP.com Disclosure Number: IPCOM000008305D
Publication Date: 2002-Jun-04
Document File: 5 page(s) / 132K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for the automated negotiation of simple network management protocol (SNMP) encoding rules. Benefits include improved performance, improved flexability, and improved reliability.

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Method for the automated negotiation of SNMP encoding rules

Disclosed is a method for the automated negotiation of simple network management protocol (SNMP) encoding rules. Benefits include improved performance, improved flexability, and improved reliability.

Background

Terminology

(See Figure 1.)

Term

Description

Management Information Base (MIB)

Database of all manageable objects contained by an SNMP-managed entity. Each managed object is identified by an OID

Network Management Station (NMS)

Network device running SNMP management software capable of sending SNMP requests and receiving SNMP responses. The NMS communicates with SNMP agents residing on SNMP-managed entities and exchanges management information (using SNMP requests and responses) with them.

Object Identifier (OID)

Identifier of a managed object in the MIB

Simple Network Management Protocol (SNMP)

Protocol used to communicate management information between the network management stations and the SNMP agents (see RFC 1157).

SNMP agent

Application residing on every SNMP-managed entity performing all SNMP protocol operations

SNMP-managed entity

Network device that can be managed using SNMP

SNMP manager

Management application residing on the NMS capable of exchanging management information with the SNMP agent via SNMP

SNMP message encoding rules

ISO-defined rules used to encode data in SNMP messages

Varbind (Variable Binding)

Structure consisting of the OID and value of the managed object

      Conventionally, SNMP messages exchanged between the NMS and the SNMP agent are encoded using BER (Basic Encoding Rules). The use of BER is implied by the SNMP standard and no other encoding rules can be used to maintain interoperability of SNMP managers and agents of different vendors. However, BER is quite inefficient. Messages encoded using BER are often unnecessarily long because BER does not support any kind of OID compression. For example, when many variables are retrieved from one MIB table, the request and response messages often contain multiple repetitions of the same OID, differing only by one or a few OID-nodes.

      Other encoding rules are defined by ISO that do not have the disadvantages of BER, including:

·        PER (Packed Encoding Rules)

·        LER (Lightweight Encoding Rules)

·        DER (Distinguished Encoding Rules)

·        CER (Canonical Encoding Rules)

              Other proprietary solutions may also exist. However, they cannot be used with SNMP because the standard permits only use of BER. To enable the use of other encoding rules, a manager would have to automatically detect which encoding rules does the agent support and both parties would have to negotiate an agreement on the encoding rules they will be using.

General description

              The disclosed method enables the SNMP manager and the SNMP agent to automatically negotiate the message encoding rules they will be using in further message exchange.

Advantages

      The advantages of the disclosed method include:

·        Enabling the usage of SNMP message encoding rules in addit...