Specifications

2. SNMP for RACOM RipEX

2.1. Simple Network Management Protocol

SNMP is a simple, widespread and useful standardised protocol used to read values from devices or

to set them. Values can be obtained at regular intervals, saved to a database and then displayed as a

graph. It allows you to, for instance, monitor activity on the radio channel, temperature history or data

flow through ports.

SNMP also enables you to generate and receive alarms (SNMP traps).

2.1.1. How does SNMP work?

SNMP protocol requires two parties for communication.

One of them is manager – you could use commercial as well as free software such as Zeenos, Nagios,

Cacti, etc.

The other is SNMP agent which is part of RipEX firmware. It does two things:

• Agent responds to manager's queries. Several managers may read values at once and they can

send their queries at any time.

• Agent sends its manager notifications (traps) in defined situations (when a value is exceeded or at

regular intervals). These traps are only sent to one manager.

For more information on SNMP and its installation and usage go to Simple Network Management

Protocol

on MSDN website.

2.1.2. SNMP communication

In SNMP each value is uniquely identified using OID (Object IDentifier) code.

Normal communication, in which first query and then response are sent, works as follows:

• A query is sent – manager sets message type to GET, includes OID for the required value and sets

the value to NULL

• Response is returned – agent sets message type to RESPONSE and sends the requested value

along with its OID

Basic query types are:

SNMP GET – returns a single value

GET-NEXT – returns next value (using the next OID)

GET-BULK – as of SNMPv2. Returns several values in a single packet (for example, the temperature,

voltage, number of transmitted messages or bytes per second, etc.).

SNMP allows you to not only receive but also set values using SET type message (unsupported by

RipEX).

Another message type is TRAP which sends spontaneous messages (values) from agent to manager.

http://go.microsoft.com/fwlink/?LinkId=45736

SNMP for RACOM RipEX