http://www.paessler.com/prtg/download
http://download-eu.paessler.com/download/prtgtrial.zip
When asked for an email address enter anything you want.
When asked for a License key click “Skip this” below the text boxes.
SNMP OIDs
Known to work with Draytek 2830
ADSL WAN1 Up Sync 1.3.6.1.2.1.10.94.1.1.5.1.2.4
ADSL WAN1 Down Sync 1.3.6.1.2.1.10.94.1.1.3.1.8.4
ADSL WAN1 SnR 1.3.6.1.2.1.10.94.1.1.3.1.4.4
ADSL WAN1 Loop Att 1.3.6.1.2.1.10.94.1.1.3.1.5.4
ADSL WAN1 InOctals 1.3.6.1.2.1.2.2.1.10.4 (DELTA!!)
ADSL WAN1 OutOctals 1.3.6.1.2.1.2.2.1.16.4 (DELTA!!)
FYI
1.3.6.1.2.1.10 = .iso.org.dod.internet.mgmt.mib-2