sub graph($$)
{
        my ($range, $file) = @_;
        my $step = $range*$points_per_sample/$xpoints;
        rrd_graph($range, $file, $ypoints,
                "DEF:sent=$rrd:sent:AVERAGE",
                "DEF:msent=$rrd:sent:MAX",
                "CDEF:rsent=sent,60,*",
                "CDEF:rmsent=msent,60,*",
                "CDEF:dsent=sent,UN,0,sent,IF,$step,*",
                "CDEF:ssent=PREV,UN,dsent,PREV,IF,dsent,+",
                "AREA:rsent#$color{sent}:Sent    ",
                'GPRINT:ssent:MAX:total\: %8.0lf msgs',
                'GPRINT:rsent:AVERAGE:avg\: %5.2lf msgs/min',
                'GPRINT:rmsent:MAX:max\: %4.0lf msgs/min\l',

                "DEF:recv=$rrd:recv:AVERAGE",
                "DEF:mrecv=$rrd:recv:MAX",
                "CDEF:rrecv=recv,60,*",
                "CDEF:rmrecv=mrecv,60,*",
                "CDEF:drecv=recv,UN,0,recv,IF,$step,*",
                "CDEF:srecv=PREV,UN,drecv,PREV,IF,drecv,+",
                "LINE2:rrecv#$color{received}:Received",
                'GPRINT:srecv:MAX:total\: %8.0lf msgs',
                'GPRINT:rrecv:AVERAGE:avg\: %5.2lf msgs/min',
                'GPRINT:rmrecv:MAX:max\: %4.0lf msgs/min\l',
        );
}