User`s manual

P-660 Series Support Notes
78
All contents copyright © 2005 ZyXEL Communications Corporation.
The current Internet-standard MIB, MIB-II, is defined in RFC 1213 and contains 171
objects. These objects are grouped by protocol (including TCP, IP, UDP, SNMP, and
other categories, including 'system' and 'interface.'
The Internet Management Model is as shown in figure 1. Interactions between the
NMS and managed devices can be any of four different types of commands:
Reads
Read is used to monitor the managed devices, NMSs read variables that are
maintained by the devices.
Writes
Write is used to control the managed devices, NMSs write variables that are
stored in the managed devices.
Traversal operations
NMSs use these operations to determine which variables a managed device
supports and to sequentially gather information from variable tables (such as
IP routing table) in managed devices.
Traps
The managed devices to asynchronously report certain events to NMSs use
trap.