1.Intro

The opennms-pmacct project aim to be a generic Netflow collector.
It collects data from the pmacct tool (http://www.pmacct.net).
Collected data are stored in the <rrd_base>/snmp/<nodeid>/<host_address> directory. 

2.Installation

2.1.PMacct installation/configuration

Install pmacct/nfacct on your OpenNMS server.
To collect netflow flows from an existing equipement (Switch, router, firewall,...), 
copy the opennms-pmacct/conf/pmacct/nfacctd.conf to the /etc/pmacct directory 
Change <YOUR-IP> with you OpenNMS Ip and <LISTEN-PORT> with the port.   
Launch the nfacct daemon.
Configure your network equipement to send netflows to your OpenNMS server.
Verify that pmacct collect flows from your equipements using the followin command :
 # pmacct -p /var/lib/pmacct/out.pipe -s

2.2.Opennms-pmacct installation

Compile this project using maven (with the "mvn package" command).
Copy the opennms-pmacct/target/opennms-pmacct-<VERSION>.jar file in the $OPENNMS_HOME/lib directory
(/usr/share/opennms/lib under Debian Lenny).  

2.3.Opennms-pmacct bandwidth sample

Copy the opennms-pmacct/conf/opennms/pmacct-datacollection-config.xml to the $OPENNMS_HOME/etc directory

Edit $OPENNMS_HOME/etc/collectd-configuration.xml and add the following configuration : 

<service name="PMACCT-BW" interval="300000" user-defined="false" status="on">
    <parameter key="collection" value="pmacct-bandwidth"/>
    <parameter key="thresholding-enabled" value="false"/>
</service>

<collector service="PMACCT-BW" class-name="org.opennms.netmgt.collectd.PmacctCollector"/>

In snmp-graph.properties add the value "pmacct.bandwidth" to the property "reports" 
and add the following graph definition :  

report.pmacct.bandwidth.name=PMACCT Bandwidth
report.pmacct.bandwidth.columns=pmacctOutbound,pmacctInbound
report.pmacct.bandwidth.type=interfaceSnmp
report.pmacct.bandwidth.command=--title="Bandwidth" \
 --vertical-label="Bits Per Second" \
 DEF:out={rrd1}:pmacctOutbound:AVERAGE \
 DEF:outMin={rrd1}:pmacctOutbound:MIN \
 DEF:outMax={rrd1}:pmacctOutbound:MAX \
 DEF:in={rrd2}:pmacctInbound:AVERAGE \
 DEF:inMin={rrd2}:pmacctInbound:MIN \
 DEF:inMax={rrd2}:pmacctInbound:MAX \
 CDEF:outNeg=0,out,- \
 AREA:outNeg#0000ff:"Out" \
 GPRINT:out:AVERAGE:" Avg \\: %8.2lf %s" \
 GPRINT:out:MIN:"Min  \\: %8.2lf %s" \
 GPRINT:out:MAX:"Max  \\: %8.2lf %s\\n" \
 AREA:in#00ff00:"In" \
 GPRINT:in:AVERAGE:" Avg \\: %8.2lf %s" \
 GPRINT:in:MIN:"Min  \\: %8.2lf %s" \
 GPRINT:in:MAX:"Max  \\: %8.2lf %s\\n"

Restart your Opennms server.
Add the service "PMACCT-BW" to the hosts you want monitor the bandwidth. 
Wait 5 minutes and enjoy.