DOCSIS Cable Modem Add-On v0.50 BETA

[JoeNetwork]

I think you need to form an SNMP-query and get the CATV/RF interface index #'s; the OIDs for SNR and other statistics are based off of that same index that you would use for Ethernet traffic if I am not mistaken.

I'm looking at doing a template for all DOCSIS CMTSes and you would simply check which upstreams to graph like you currently would w/Ethernet Bits In/Out in Cacti but just haven't gotten around to it yet.

[Scipio]

Try to use the SNR data template. Normally, there is nothing more to do than relax and enjoy...

[sx]

ac

[ItsNewToYou]

Awsome stuff guys and gals. I have been looking for this kind of stuff for awhile. I am very dumb when it comes to creating these myself and now can stop pounding my head on the desk. I have 9 VXR and 30,000 plus modems I monitor with Cacti.

ItsNewtoYou

[WillB]

These look awesome, and I'm trying to get them put together, but I'm having an issue with no results getting populated. When checking the cacti.log I'm getting "Warning: Result from SNMP not valid. partial result: 35.4 dB". The end value is obviously that of the device. This is occuring both with the OP's templates, and those of Scipio. This makes me think its a MIB issue, but I can't be sure. Could someone with a functional installation post the results of an snmpget to any of the variables used in these plugins? I'm particulary curious if yours returns the value appended with dBmV or dB. Since the log files report a value of U (out of range) my gut feeling is this may be part of the issue. of course, I could be crazy.

Thanks for any help.

[cort]

I'm just curious. What does the Microreflections tell you? If i.e a cablemodem has a bad value what may cause this?

I've searched for an answer but with no luck

[BSOD2600]

I'm just curious. What does the Microreflections tell you? If i.e a cablemodem has a bad value what may cause this?

Microreflections can destroy a cable-based signal, and they are a fact of life. Most existing cable plants suffer from impedance mismatches from unauthorized splitters, missing terminations, damaged or cut cabling, etc. In spite of this fact, there is often no means for correction on the network. In fact, this is one of the very few cases where a performance issue has been “promoted” to the level of the interoperability specification. Version 1.1 of the DOCSIS ATP calls out a test (PHY-20) that forces a system to perform pre-equalization so that the signal has a usable modulation error ratio (MER) in the presence of reflections.

It’s easy to say that impedance mismatches are the responsibility of the cable company and/or MSO, but successful products will account for this reality. Remember that subscribers don’t care about stub-matching or allowable tolerances. All they’ll remember is that one brand of one device works, and another doesn’t.

[cort]

Thanks for clearing this up BSOD2600

I assume a value: Microreflections=0 dBc is the best value (but impossible to gain?)

Do you know how high the value can be before it starts making trouble?

thanks in advance

[BSOD2600]

I'm not sure on whats too high of a value. Took me a good 10 min on google to actually find a decent description of what microreflections are.

Here are my modems stats for the past ~9 months for an idea of I guess, OK microreflection values.

[Scipio]

Hi !

About the microreflexions, I don't know what is a good value and a bad value. Maybe I'll do a lab test with crappy connectors if I found some time. But with our modems, I saw values from 20 to 40, and a few modems with a 0 value.

When I do a test for these values, I'll put a feed back here.

Regards from Switzerland !

[cort]

looking forward to see your results.

From what I have understood it's a value that is below the carrier signal

If the carrier signal is 40 dBmV (i assume the carrier signal is the upstream signal )

Then the Microreflection should be around 30dBc measured after 0.5 microsecond.

-10 dBc @ <= 0.5 microsecond
-15 dBc @ <= 1.0 microsecond
-20 dBc @ <= 1.5 microsecond
-30 dBc @ >1.5 microsecond

Maybe I'm way off here

Like Cisco says:

Total microreflections including in-channel response
as perceived on this interface, measured in dBc below
the signal level.
This object is not assumed to return an absolutely
accurate value, but should give a rough indication
of microreflections received on this interface.
It is up to the implementer to provide information
as accurate as possible.

[qwerty12345]

Hi, can some one give me templates to get errors from modem, atualy i need:
1)Descriptor: docsIfSigQUnerroreds
MIB Module: DOCS-IF-MIB
Identifier: 1.3.6.1.2.1.10.127.1.1.4.1.2
SMI Macro: OBJECT-TYPE
Max. Access: read-only
ASN.1 Syntax: Counter32

2)Descriptor: docsIfSigQCorrecteds
MIB Module: DOCS-IF-MIB
Identifier: 1.3.6.1.2.1.10.127.1.1.4.1.3
SMI Macro: OBJECT-TYPE
Max. Access: read-only
ASN.1 Syntax: Counter32

3)Descriptor: docsIfSigQUncorrectables
MIB Module: DOCS-IF-MIB
Identifier: 1.3.6.1.2.1.10.127.1.1.4.1.4
SMI Macro: OBJECT-TYPE
Max. Access: read-only
ASN.1 Syntax: Counter32

I try to do it by my self, but nothing work where is a problem i dont know, byt cacti-docsisCM-0[1].50 work fine, thx.

P.S Sorry for my bad english.

[hapklaar]

I can't get the graph with the 5 upstream S/N values to work. Getting 0.00 values.

Looking at the debug logs, something seems wrong:

11/04/2005 03:00:07 PM - CACTID: Poller[0] Host[21] WARNING: Result from SNMP not valid. Partial Result: U...
11/04/2005 03:00:07 PM - CACTID: Poller[0] Host[21] SNMP: v1: nv-cuda, dsname: snr, oid: .1.3.6.1.2.1.10.127.1.1.4.1.5., value: U
11/04/2005 03:00:07 PM - CACTID: Poller[0] DEBUG: SQLCMD: insert into poller_output (local_data_id,rrd_name,time,output) values (2055,'snr','2005-11-04 15:00:00','U')

The actual OID's should be revealed by a snmpwalk and queried. Think that is what's supposed to happen.

When i snmpwalk the OID, I get:

[root@vdtcache etc]# snmpwalk nv-cuda public .1.3.6.1.2.1.10.127.1.1.4.1.5
transmission.127.1.1.4.1.5.9043971 = 292
transmission.127.1.1.4.1.5.9043972 = 194
transmission.127.1.1.4.1.5.9043973 = 290
transmission.127.1.1.4.1.5.9043974 = 298
transmission.127.1.1.4.1.5.9043975 = 283
transmission.127.1.1.4.1.5.9043976 = 170
transmission.127.1.1.4.1.5.9044035 = 258
transmission.127.1.1.4.1.5.9044036 = 194
transmission.127.1.1.4.1.5.9044037 = 231
transmission.127.1.1.4.1.5.9044038 = 462
transmission.127.1.1.4.1.5.9044039 = 298
transmission.127.1.1.4.1.5.9044040 = 262


Did anyone get this to work or maybe see what's going wrong?

[dexter001]

great thing .. after a couple of months of tryin' to do it on my own ..I found your script .. it's just great :) I have a thomson tcm420 .. seems to be fine :) .. what's the status of your script !? still working on it ? .. how's the todo list with the cmts support ? :) it would be neat :) .. ( I have a 3com hiper cmts .. so if I can help with devel .. lemme know :) )

[dk10tlx]

Hello,

I've tried to get this template working, and it works now as expected. Really good work, many thanks.

There's only one thing that makes me a little bit "un-satisfied" ...

The downstream doesn't show up correctly.

Cacti shows me "nan", although when I do the following on the commandline, it seems to work:

Code: Select all

snmpwalk -v 2c 192.168.100.1 -c public .1.3.6.1.2.1.10.127.1.1.1.1.6.3
SNMPv2-SMI::transmission.127.1.1.1.1.6.3 = INTEGER: 120

Also the logs show up correctly:

Code: Select all

08/06/2007 11:29:04 AM - CACTID: Poller[0] Host[12] DS[159] SS[0] SERVER: /usr/share/cacti/site/scripts/ss_docsis_stats.php ss_docsis_stats 192.168.100.1 public 2 161 500 MyROGroup , output: docsIfDownChannelPower:120 docsIfSigQSignalNoise:310 docsIfSigQMicroreflections:17 docsIfCmRangingTimeout:20 docsIfCmStatusTxPower:487 docsIfCmStatusResets:3 docsIfCmStatusLostSyncs:11 docsIfCmStatusT1Timeouts:0 docsIfCmStatusT2Timeouts:0 docsIfCmStatusT3Timeouts:7 docsIfCmStatusT4Timeouts:1 

In the data source I use "divide by 10", so the result should be "12,0", am I right? Is there anything else I could try to modify to get it working correctly?


RRD and qury debug show OK.


The Modem is a Kathrein DCM52i (from my ISP) which the manufacturer says "supports MIB-II; Ethernet-like MIB, Bridge MIB, Cable Device MIB, Baseline Privacy Interface MIB, RF Interface MIB".

Any help is highly appreciated.

thanks & regards
Daniel