CGN3ACSMR Lan port

[huh666]

The modem was replaced with another CGN3ACMSR. Firmware is 4.5.8.16. Unable to copy and paste upstream and downstream as I am at work right now. When I checked they appeared similar with the upstream number around 43. Still randomly losing connection even when the modem is hooked up directly to the cable feed coming into my house. I am suspecting that it is outdoor wiring. Because it began when the thaw began and it has been raining today. Will post the up and downstream numbers when I get home. Thanks

[huh666]

As requested Datalink:

Downstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Signal noise ratio (dB)
1	693000000	256QAM	-0.200	23	40.366
2	561000000	256QAM	-1.900	2	40.366
3	567000000	256QAM	-1.700	3	40.946
4	573000000	256QAM	-1.500	4	40.946
5	579000000	256QAM	-1.400	5	40.366
6	585000000	256QAM	-1.100	6	40.366
7	591000000	256QAM	-1.500	7	40.946
8	597000000	256QAM	-0.900	8	40.946
9	603000000	256QAM	-0.900	9	40.366
10	609000000	256QAM	-0.200	10	40.946
11	615000000	256QAM	-0.500	11	40.946
12	621000000	256QAM	-0.300	12	40.366
13	633000000	256QAM	-0.200	13	40.946
14	639000000	256QAM	-0.600	14	40.946
15	645000000	256QAM	-0.500	15	40.366
16	651000000	256QAM	-0.700	16	40.946
17	657000000	256QAM	-0.200	17	40.946
18	663000000	256QAM	-0.500	18	40.946
19	669000000	256QAM	-0.300	19	40.366
20	675000000	256QAM	-0.300	20	40.946
21	681000000	256QAM	-0.400	21	40.946
22	687000000	256QAM	-0.400	22	40.366
23	555000000	256QAM	-2.200	1	40.366
24	699000000	256QAM	-0.200	24	40.946

Upstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	BandWidth
1	23700000	ATDMA - 64QAM	46.750	5	6400000
2	38596000	ATDMA - 64QAM	47.000	6	3200000
3	30596000	ATDMA - 64QAM	46.750	4	6400000

 This is a photo of the modem. 

Thanks again

[huh666]

I have Rogers Whole Home PVR so my main cable feed into the house runs into an Antronix MVRA501B integrated MoCA PoE filter.  Now I appear to be having problems with my whole home pvr setup too.  Is it possible that the filter could be causing the issues?

[huh666]

Just to update everyone I think I have found what causes the LAN ports to "power off". I have been able to replicate this 100% of the time no matter what the modem is connected to.  It seems that if the modem loses sync while in bridge mode it "turns off" and they do not get reset.  The power must be cycled for the lan ports to be reactivated.  I have replicated this while connected to a Netgear Nighthawk R7000 router, DLINK Dir-615 router, my pc and a laptop.  I am on my third modem now and still have the same issue.  I don't know if this is a hardware or firmware issue with the CGN3ACSMR modems.  .  Who should I contact about this, because I know tech support would be useless.  Anyone else willing to see if they can replicate this?

Thanks

[Datalink]

The only people able to test for this, or examine their DOCSIS LOGS and come to the same conclusion are those who are experiencing a synchronization failure.  In one of your previous posts is the following from the DOCSIS LOG:

SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xxxxxx;CMTS-MAC=xxxxxxxx;CM-QOS=1.1;CM-VER=3.0;

The fact that the ports shut down makes sense as the modem has lost its synchronization with the Cable Modem Termination System (CMTS) and therefore is unaware of the transmission time slots that are assigned and available to the modem for the purpose of sending any type of data back to the CMTS.  Those transmission time slots are determined by the CMTS.  So, there is either a signals issue, or a neighborhood node issue going on.  I would suspect that anyone tied to the same cable tap would suffer the same issue.  If your cabling is underground, you would have a cable tap within sight of your house, small green box, about waist high that distributes the cable signals to a small group of homes, usually four homes I believe. 

When you see this occur, call Tech Support asap, and after explaining what you have just experienced ask him or her to check the other modems tied to your specific tap to determine if they are offline as well, as that would point to a problem with the neighborhood node, and not with your cabling.  Don't reset the modem, let the tech see the failure.  Hopefully your call will beat your neighbors to the punch, and the tech will see the same issue with their modems before they have a chance to reset their modems. 

Are you seeing the loss of SYNC show up in the logs whenever you have a port failure?  I'm assuming that you have to reset the modem to log back in, or are you able to log into the modem via wifi connection when the LAN ports shut down?  I had thought that a modem reset would wipe the DOCSIS log and restart it, losing all of the previous entries.  Maybe not ??

Have a look at the first page of the following document regarding the DOCSIS synchronization.  That provides a brief overview on the subject, with a diagram on the following page.

http://www.scientific-devices.com.au/pdfs/WeTransfer-NZvJB6Cw/Telecommunication%20Synchronization/Sy...

[huh666]

Thanks for the advice.    Resetting does clear any existing logs.  This issue does not occur when the modem is in gateway mode.  Another thing that I failed to mention is that the modem will regain sync but the LAN ports remain dead.  Thanks again for everything

[sm30]

I believe I am having the same issue as you. I have been having this issue since February 23rd. My modem loses internet connectivity and the LAN lights on the front and back stop working. All the other lights are on and active.

The only way to regain an internet connection is to reset the modem. I also have the CGN3ACSMR modem with firmware 4.5.8.16 and in bridge mode. I have had this modem for the past year and did not have any issues before.

I have been noticing that it loses connection every night. Sometimes it even cuts off more than once during the day. I have spoken to tech support many times and I have had tickets open for a node issue and neighbourhood/signal problem. They came back and said the issue has been fixed but I am still having the same problem. On Monday I had the modem swapped out but this issue continued. I had a tech supervisor come out on Friday and he said the connection and signals were good. He replaced my splitter and changed all the cable connectors as a precaution. The last thing he wanted to do was replace my modem with the CGN3, the one without the AC wireless feature. I told him no because I had replaced the modem already that week and the problem is still happening.

Your conclusion about the modem LAN ports going into "sleep mode" makes sense. How are you able to test that without waiting for it to go down?

This is frustrating and I don't know what to do next.

[huh666]

Hi sm30, I'm glad to hear that I am not the only one having this problem!  I jusst got off the phone with tech support again and they checked my connection and my neighbours and said they saw something. I have a tech coming out for the second time on Tuesday the 15th and I hope that they can resolve it.  Once the modem goes down there is no way to test or check logs.  Out of curiosity where are you located.  I am in Brampton.  Just trying to determine if it is a regional issue.  I remember at one point late last year parts of Brampton were unable to connect to www1.shoppersdrugmart.ca and it took Rogers 3 or 4 months to resolve that issue.

[sm30]

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@huh666 wrote:

Hi sm30, I'm glad to hear that I am not the only one having this problem!  I jusst got off the phone with tech support again and they checked my connection and my neighbours and said they saw something. I have a tech coming out for the second time on Tuesday the 15th and I hope that they can resolve it.  Once the modem goes down there is no way to test or check logs.  Out of curiosity where are you located.  I am in Brampton.  Just trying to determine if it is a regional issue.  I remember at one point late last year parts of Brampton were unable to connect to www1.shoppersdrugmart.ca and it took Rogers 3 or 4 months to resolve that issue.

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I am also located in Brampton. I am near Torbram and Sandalwood, how about you? Please let me know what happens on Tuesday. I will also keep you updated if I hear anything on my end.

[huh666]

I'm in the "b" section of Bramalea at Dixie and Orenda. Ironically right by Rogers HQ on Dixie Road. A way I have found to "test" the LAN ports going to sleep is by unplugging the cable from the modem and waiting for it to lose sync. At that point the LAN light goes off. The Rogers tech also tried to swap out my modem forba CGN3 and I said no way. Maybe Rogers knows something and they aren't letting us know. Let's hope this info helps Rogers solve our problem.