So, intermittently, my CGN3 modem will reboot itself. All the lights, except the power light, shut off and it takes about 3 minutes to come back up. This evening, this happened about 5 or 6 times in the span of 90 minutes. This issue had occured to me before and after speaking with a Rogers tech, the modem was exchanged and no issues were had for about 3 weeks, until this evening. What are the odds of 2 defective modems? The last time this happened, a tech ended up coming after I replaced the modem and tested the signal and said it was very good.
I spoke with tech support again this evening and they're sending another tech but I am skeptical that they'll find anything wrong. Any ideas?
Solved! Solved! Go to Solution.
When you do a factory reset by pressing the button in the back of the modem does it need to reinstall the firmware which causes the modem to reset a few times after a few hours? Seems like every evening my modem is resetting and I am trying to figure out why.
Thank you for posting your query in the Community. The modem may look up for the latest firmware while coming back online; however, it should not reboot every evening. The CGN3 modem should be running 18.104.22.168T12 firmware version. Has the problem returned from last year?
Good morning @Geezup!
If your modem is stuck in a pattern of rebooting on its own, I can help. I know an intermittent connection can be frustrating so please work with us.
Seeing your modem reboot every few days is certainly indicative of an issue. Thanks for letting us know! Have you reached out to technical support yet to have your modem signals reviewed? If your familiar with how to access the modem's settings you can copy and past the signal level results from the WAN Status page and paste them for the community here. Just a couple of quick questions if I may as we'll need quite a bit more information to be helpful:
If the modem is dropping connection completely and rebooting it sounds like there may be an RF issue, so one or more channels to your modem may be out of spec. I definitely recommend reaching out to support at your earliest convenience if you haven't yet. You can reach them via phone, Live Chat, twitter or Facebook. Information for each can be found here. Alternatively you can reach out to us @CommunityHelps. For more information on our PM system you can check out our blog.
Modem rebooting while streaming videos on an Android device
Just checking if anyone has encountered this problem, out of all my wired computers and wireless devices only when I stream a video from my Samsung S9 device it triggers the modem to reboot. Does not do that when I stream from any other devices. I have the CGN3 just the rocket modem. I could probably make a video if someone else has this problem. It's the weirdest thing. I checked my mibs from the modem firmware and they are good.
Thanks for participating in the Rogers Community Forums, it's great to have you here!
I must admit, I've personally never heard of such a strange occurrence before! How odd!! 🤔 A few questions for you...does this issue of your modem rebooting while streaming on your S9 happen every single time? Or is it intermittent? And just to clarify, this ONLY happens while streaming and not during any other tasks?
We look forward to your response! 🙂
Poor upstream signal modem reboots
I ended up changing the location of my modem to a different room. This resulted in poor upstream signal at 57 dB. The line for this cable comes from the green box, connected to a 4 way splitter -7dB in the garage, that line then is connected to a coupler in the garage because it is too short then it goes upstairs, next it travels to the master bedroom and is connected to another splitter this time -3.5dB, then travels to another room about 15 feet away and is connected to another splitter -3.5dB and then finally connects to the modem.
Tech came out and gave me an antronix amp. He also stated all the lines outside the house were good. I tried using the amp and these were the results
4 channels around 50dB. I woke up and checked the docsis event logs and there was a t3 timeout at around 3am. Why is this? Is there nothing else I can do a part from removing splitters to prevent the modem from rebooting? I'm looking to get a new line to this room but because of covid the techs aren't allowed inside
@Theguy45 the CGN3xxxx model modems typically run with a 36 to 40 dBmV output level for the upstream channels. Each splitter that the cable runs through will drop the downstream level by the amount indicated on the splitter port, but, it also drives up the required upsteam output of the modem. So, if you add the splitter drops, 7.5 + 3.5 + 3.5, that gives you 14.5 dB. So, the downstream level drops by 14.5 dBmV and the upstream output will increase by the same 14.5 dBmV.
The 36 to 40 dBmV upsteam output level that I indicated doesn't take into account the signal levels on the incoming cable when it enters your home. From the splitter configuration that you indicated, you have very little room, perhaps none at all, until the modem exceeds its upstream output levels, which according to the DOCSIS specs is 51 dbmV for three or four upstream channels. Rogers uses 52 dBmV for some reason. At that 51/52 dBmV level, the modem will automatically shut down one channel and use the total output power available for the remaining channels. If that doesn't meet the required signal levels at the Cable Modem Termination System (CMTS), the modem will shut down another channel, and will keep doing so until it can maintain comms with the CMTS. That is totally automatic. So, the starting point would be to connect the modem to the incoming cable to determine the baseline numbers, downstream and upstream. With the upstream power levels, you would know exactly how much room you have between those numbers and the 51/52 dBmV failure point.
The amp that the tech supplied won't help. That amp should have a Voip port marked on the front. That port is the port that should be used for the modem. That port is not amplified. The remaining ports will be amplified. The internal configuration is essentially like a two port splitter, one port to the VOIP port, the other to the amplifier and its ports. The amped ports should not be used for the modem as you can run into packet loss issues. That's why the VOIP port should be used. So, given that info, that really negates any potential gain from using the amp, at least when it comes to amplifying the cable output to the modem. For any thing else connected to the amp such as a Nextbox or Home phone, you should be ok with those ports. If you're using the amp in that configuration, that's the best you can do with the amp.
One test or series of tests I would recommend is to use the modem as test tool, connecting it point by point, starting with the incoming cable, then the amp or splitter port, then the end of the next cable section, then at the output port of the splitter connected to that cable end, etc, etc. Collect the data as you go along, looking for any excessive losses in the cable sections or splitter outputs. As I indicated above, you don't have much signal level slack to play with, so, every db counts.
The last suggestion that comes to mind is to determine if there is any way you can run cables from some point in the house that would allow you to run long RG-6 cable sections and not use any splitters, thus avoiding any signal losses from the splitters. That might be difficult to do, and you may have to call in an electrician to snake cables thru the walls. In the long term, that would probably be the best solution. It definitely has a cost to it, but, would provide simplest solution if it can be done.
Would you happen to know if the cables in the house are RG-59, which would be pretty old, or are they RG-6 cables. The RG-59 cables have a higher signal loss at higher frequencies.
@Theguy45 the packet loss is from the amplification process itself, but, in your case, you can certainly try using any of the amped ports. If you do, I would definitely keep an eye open for any signs of packet loss. Rogers switched to the current model of amps which have that VOIP port and amped ports a few years ago, as the previous amps, which amplified everthing caused packet loss for the internet modems. So, my recommendation to date has been to use the VOIP port for the modem. The only problem that arises is when a customer has both internet modem and a VOIP phone.
If you look at the cable jacket, you should see the specs printed on the jacket. It will indicate RG-59 or RG-6. I suspect that you will have RG-59, but, I might be wrong. Only way to really be sure is to check the individual sections. If you take a wallplate off of the wall and gently pull the wallplate and cable out, you will hopefully be able to see what cable type it is. If you happen to have a section of RG-6 cable on hand, take note of the size of the cable. Its slightly bigger than the RG-59 cable, so in the absence of specs on the cable jacket, hopefully you will hopefully be able to determine what cable you have based on the cable size.
@Theguy45 that cable appears to be RG-6 cabling. Its possible to damage the cable if its bent too sharply. I can't find the specs for that specific cable but modern RG-6 cable typically uses the following;
Minimum Bend Radius, loaded, times 20 times
Minimum Bend Radius, unloaded, times 10 times
So, with a little google-foo,
1. the loaded figure is 20x the outside radius of the cable when its under a tensile load, as in its stretched from point to point;
2. the unloaded figure is 10x the outside radius of the cable when there is no load on the cable.
An easier figure to look at is from the following page: https://en.wikipedia.org/wiki/Bend_radius
Basically that 7 cm minimum figure equates to a 2.75 inch radius for bending purposes. So, in theory you don't want to bend the cable any smaller than that.
For the packet loss testing, ping the Cable Modem Termination System. The path to the CMTS is as follows:
1. modem to demarcation point at the side of the house via house RG-6 cable:
2. demarcation point to local tap, either at a local pedestal or nearby utility pole via RG-6 cable:
3. local tap to neighbourhood node via hard cable:
4. neighbourhood node to CMTS via fibre optic cabling
Running a ping test to the CMTS keeps any network issues beyond the CMTS out of the picture. To do this, run an IPV4 trace to anywhere:
tracert -4 www.google.ca
If the modem is running in Gateway mode, with a direct connection to the modem, the first hop IP address will be the modem, the 2nd hop will be the CMTS IP address. Ping the CMTS IP address.
Its your choice to run a short term ping test, ie: an hour or more, or run a continuous test for several hours. If you can, I'd let it run for several hours.
ping -t xxx.xxx.xxx.xxx where xxx.xxx.xxx.xxx is the CMTS IP address.
When that test is done, consider posting the results. To do that, right click on the top title bar of the command box. Select Edit .... Select All. Right click again .... Select .... Copy. Then paste that into a text editor of some type so that you can copy the bottom results and paste them into a post.