Level 1: Cadet

Cable connection drop out issues



First, a disclaimer - this is my first post on this board and I have no prior knowledge of cable modems, so apologies if I have posted this to the wrong board and / or should have attached my comment to a different thread.



I live in Willoughby in Sydney.  I have had a CG3100D-2 cable modem and Telstra Bigpond Ultimate for about 12 months, and have had internet dropout issues since installation.   


Typically what happens is that the modem will lose its connection to internet (the "internet" led blinks) but the wifi connection remains stable.  As a result, devices connected via wifi think they have an internet connection but no data is transferred.


The modem appears to try to reconnect to the internet and is occasionaly successful, but the only reliable solution to reestablish the connection issue is to turn the modem off, unscrew the coax cable, wait 30 seconds, reattach the coax and turn the modem back on.  


Attempted fixes

The first fix I tried was to have an electrician install a new coax cable between the modem and the telstra cable junction box around 9 months ago.  This was done as part of a renovation, the electrician was certified, and I'm confident the job was of a good standard.


The next attempt was via a complaint lodged with Telstra around 3-4 months ago and a regular tech came out, reviewed my modem's power levels, noticed that the downstream power level wasn't ideal (~-7 dBmv from memory) and replaced the splitter.  


I think the second attempt helped reduce the regularity of the dropouts, but we still have days / weeks where the modem will dropout 3-4 times a day.  I haven't noticed if dropouts are related to weather.


Current status

As a result of the continued dropouts, I've tried to read a number of the complaints / comments on this forum and have taken a look at my modem power levels.


Last night, while connected, my modem downstream power (average across 6 bonded channels) was ~-1.5 dBmv and the SNR was ~40 dBmv, which apparently are within normal ranges.


My upstream power however was 57 dBmv (one bonded channel), which apparently is out of the normal range.


I don't have log data with me at this point in time.



- Is it likely my dropouts are related to the upstream power level of 57 dBmv?

- Noting that I have new coax cable and connections from the modem to the Telstra junction box, what are the possible causues of the 'out of range' upstream power level?

- Is it worth requesting that a L2 tech monitor my account for a couple of weeks to try to provide a better answer, or, are there any other recommendations as to how we might be able to improve the reliability of our upstream signal?

- I have read elsewhere that switching the CG3100D-2 into bridge mode and using an independent router may improve performance.  Is doing this likely to help improve the connection performance? 


Thanks in advance.


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Level 23: Superhero

Re: Cable connection drop out issues

Good morning


Firstly, I will offer some basics to check (again)

If you are using WiFi, compare using a good quality ethernet cable.

Have you tried on a completely different computer using ethernet.


High on my list ... the actual street pit and the  cabinet outside your house.

The pits are legendary for moisture and corrosion problems....even a loose or poor physical connection.

 The cabinet outside your house should be carefully checked.


Have a look at the link I have provided please


I think you should ensure you really get a Level 2 technician, after the history you have provided.

Many thanks


If I have helped you, a "Like" would be appreciated.

If my advice is a solution, please acknowledge it.

I'm not a Telstra employee.
50 + years exp. in radio comms., eg mobile phones since 1963, two-way radios, base stations, antennas & pagers. Expert in current Telstra Go repeaters & smart antennas.
"Being 75 years of age, entitles one to be an expert at everything!!"
Level 1: Cadet

Re: Cable connection drop out issues

Thanks for the quick response.  


To be honest I haven't actually tested connectivity over ethernet as my assumption was that it wasn't the wifi connection (which typically remains steady), but rather my modem connecting to the internet (which doesn't).  Next time I have a dropout, however, I'll give it a go.


Regarding speedtests, again I haven't tried over ethernet but I've run them over wifi before and - when the modem is connected to the internet - have been very happy with the results (~100mbps) and have no issues at all streaming HD quality video.


Do you, or any other forum contributers, have a view on 

- whether it is likely the dropouts are related to the poor (?) upstream power levels? and

- whether bridging the CG3100D-2 might help? 


Again, thanks for your help.



Level 2: Rookie

Re: Cable connection drop out issues

Hi, did you ever resolve this issue, as it is identical to the problem I am having myself.
Level 1: Cadet

Re: Cable connection drop out issues

I'm having the same problem in Illawong, Sydney.   


A Telstra tech visited, claimed to improve the situation and to let him know if it wasn't resolved.  Sadly I lost his number so now I have to go through the help desk again :-(


I work from home so it has a huge impact on me, not that I can push that case with telstra since i'm on a conventional consumer cable product.


Its frustrating because I am happy to pay to have this fixed.


I lost connectivity 20-30x today, each outage is perhaps ~20 seconds long.

Support Team
Support Team

Re: Cable connection drop out issues

Hi superbob, 


Not good to hear of the ongoing drop outs. 

You should never have to put up with ongoing issues, and if you find that this is not getting resolved, a formal complaint can be lodged via these methods: Lodging a complaint with Telstra including online here:

From there a Complaint Case Manager will be assigned to assist. 

Need help? Check out our Community Wiki or Support Portal || Looking for a new mobile? Order online today || Get help with any Tech at Home with Telstra Platinum || Don't forget to tag answers as Accepted Solutions and give a Like to the member(s) who helped you out.

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