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by JoeNetwork (joe@engops.net)
ChangeLog
v0.50 - September 20, 2004
Initial BETA release, provides graphing for basic DOCSIS RF performance SNMP OIDs:
- Downstream Power
- Downstream SNR
- Upstream Power
- T3 Timeouts
- T4 Timeouts
- Lost SYNCs
- Interface Resets
Introduction
Part of the difficulty with DOCSIS CM OIDs is that, unless it's in the DOCSIS CM Event Log, you have no idea when errors actually occurred. Using cacti, especially with the graph zoom feature, you can now tell exactly when they came in and look for trends.
This is intended to be used as a reactive tool for areas in which you want to monitor specific (but not ALL) of your cable modems, i.e. an area in which you might be trying to troubleshoot an intermittent problem with the cable plant.
Requirements
o A working cacti v0.8.6 *RELEASE* installation.
o DOCSIS Cable Modem device(s) to test on.
Installation
Simple. Select "Import Templates" under "Import/Export" within your cacti console.
First, import all Data Templates, followed by the Graph Templates. You'll probably want to do Host Template last. You can import by browsing to a local file on your web client, or by pasting the content of each XML file into the box -- either way should work.
You should now have "DOCSIS Cable Modem" as a selectable device type when you add a new device. The DOCSIS graphs should be selected by default. If you want to also graph interface bandwidth, select that also. Then click "Create Graphs for This Host" and place checkmarks by
the values that you would like graphed, and choose Create.
After one or two polling intervals, you should be in business, just like with any other graph.
ToDo
Things I would like to do, but don't have the know-how or resources to do just yet:
- DOCSIS CMTS templates -- it's coming, but will require a Data Query. Don't expect the modem table though. This will likely be used for graphing the DS/US ports, and Upstream SNRs.
- Have Downstream Power start at -30dBmV instead of 0, so the graph always forms from the bottom.
- Figure out a way to make the Downstream SNR a line over the top of the Downstream Power graph, and perhaps rename it to "Downstream Signal". Some math calculations will need to be done to determine where the noise floor lies.
- A way to display Codeword values from the DOCSIS MIB. I'm hoping to have a single graph perhaps display the total Codewords with Unerroreds, Correcteds, and Uncorrectables displayed as overlays or stacks -- problem is, I am not yet familiar enough with RRDs/GPRINTs/CDEFs to do it.
- An automatic way to import device descriptions/IP addresses, based on CSV or tabular input.
- EuroDOCSIS. Not sure if it uses the same MIBs, and if things are measured the same way.
- PacketCable MTA support. I don't have all the necessary test gear yet.
Screenshot:
