User manual

Chapter 6. SNMP Operation
47 Version 1.2 Apr 2006
6.1 General
The Simple Network Management Protocol (SNMP) is one of many protocols in the Internet
Protocol (IP) suite. SNMP is the protocol recommended specifically for the exchange of
management information between hosts residing on IP networks. Network management allows you
to monitor and control network devices remotely using conventional computer network technology.
The SNMP management functions of the Fiber Multiplexer are provided by an internal
SNMP agent, which utilizes out-of-band communication over standard 10Base-T or 100Base-TX
Ethernet. The SNMP agent is compliant with the SNMPv1 standard. SNMP communications use
the User Datagram Protocol (UDP). UDP is a connectionless transport protocol, part of the TCP/IP
suite. The SNMP application uses an asynchronous command/response polling protocol and
operates at the OSI Layer 7 (Layer 7 is the Application Layer. Other IP applications that operate at
this layer are FTP, Telnet, HTTP, SMTP, etc.). All management traffic is initiated by the SNMP-
based network management station. Only the addressed managed entity (agent) answers the polling
of the management station (except for trap messages).
6.2 SNMP Operations
The SNMP protocol includes four types of operations:
getRequest Command for retrieving specific value of an "instance"
from the managed node. The managed node responds
with a getResponse message.
getNextRequest Command for retrieving sequentially specific
management information from the managed node.
The managed node responds with a getResponse
message.
setRequest Command for manipulating the value of an "instance"
within the managed node. The managed node responds
with a getResponse message.
trap Management message carrying unsolicited
information on extraordinary events (that is, events
which occurred not in response to a management
operation) reported by the managed node.