Alstom DS Agile H38 Series, Инструкция по установке и эксплуатации

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Global Documentation H38x/EN GL/D11
DS Agile H38x Page 15/53
This product supports the store and forward mechanism of the IEEE 802.3 standard. It
forwards messages with known addresses to the appropriate port. Messages with unknown
addresses, broadcast messages, and multicast messages are forwarded out to all ports
except the source port. It does not forward error packets or 802.3x pause frames.
3.3 SNMP Management
Simple Network Management Protocol (SNMP) is the network protocol developed to manage
devices on an IP network. SNMP is based on a model consisting of a manager, an agent, a
database of management information, managed objects and the network protocol. The
manager provides the interface between the human network manager and the management
system. The agent provides the interface between the manager and the physical device(s)
being managed according to the figure below.
Board
SNMP Agent
Manager
(MIB Browser software)
Management
Database
Network protocol
Messages
Management
Database
HMI
S1032ENa
FIGURE 3: SNMP MANAGEMENT
The manager and agent use a Management Information Base (MIB) and a relatively small
set of commands to exchange information. The MIB is organised in a tree structure with
individual variables, such as point status or description, being represented as leaves on the
branches. A long numeric tag known as an Object IDentifier (OID) is used to distinguish each
variable uniquely in the MIB and in the SNMP messages. The Manager is an MIB Browser
Software. SNMP versions 1, 2, and 3 are supported.
Each SNMP element manages specific objects with each object having specific
characteristics. Each object/characteristic has a unique object identifier (OID) consisting of
numbers separated by decimal points (for example: 1.3.6.1.4.1.2682.1). The MIB associates
each OID with a readable label (for example: dpsRTUAState) and various other parameters
related to the object. The MIB then serves as a data dictionary or codebook that is used to
assemble and interpret SNMP messages.
For this product, the Alstom management information bases (MIB) use the following types of
object identifiers (OID):
−
System
−
Interface
−
Remote network monitoring (RMON)
−
Parallel redundancy protocol (PRP)
These are defined in the tables below.