User manual

Appendix A. SNMP
A-2 TDU 120e User Manual 61202156L1-1
manager to retrieve or modify a particular piece of
information about a network device, the network manager
transmits the request to that network device. The agent in
that device interprets the incoming request, performs the
requested task, and sends its response to the network
manager. The network manager collects all the data from the
various network devices and presents it in a consistent form.
Network Manager Commands
Using SNMP Version 1, the network manager can issue three
types of commands:
GetRequest
Retrieves a single item or the first in a series from a network
device.
GetNextRequest
Retrieves the next item in a series from a network device.
SetRequest
Writes information to a network device.
Network Messages
The network device issues two types of messages:
GetResponse
The response to a network manager GetRequest or
GetNextRequest command.
Trap
An unsolicited message issued by a network device to report
an operational anomaly or an alarm condition to the network
manager.
These messages are typically encased within informational
packets and transported over the LAN or WAN (wide area
network).