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Possible CGN3 issue - need the pro's to look at the stats

netwrks
I Plan to Stick Around

I've been dealing with what looks to be either a Rogers Internet issue, or  CGN3 issue. (Hybrid 60 package - 60 down 10 up).

 

The CGN3 runs fine for a while, meaning speed test are consistently good. getting the 60+ down 10 up. Then out fo the blue, I will either get ZERO up, or maybe 3 mbps.  It happens wirelessly, or wired. I was running the CGN3 in bridge mode, but swithed it to router mode, so that I could connect to it and gather info. It's acting as a router, with all wifi disabled, etc.

 

Yesterday after experiencing crappy speed tests, I brought the CGN3 back to Rogers for a new one. Plugged it in, made some config changes and was off to the races.. For about 12 hours.. I was running the speed test on wireless throughout the evening, yesterday, and for a while this morning, and it was running like a champ.. BUT, then it started it's really crappy upload times, (at one point ZERO up - the UPLOAD timed out). so I went to the router, plugged into it with a LAN cable (wifi to laptop turned off) and recorded more crappy times.. Below are the DOCSIS stats before and after reboot. At the bottom of the DOCSIS Stats is the sytem info. Let me know your thoughts. Thanks!

 

-------------------------------------------------

Feb 19 before reboot  ~ SpeedTest (Rogers) - 78.29mbps down 3mbps up

Downstream Overview
Port ID Frequency (MHz) Modulation Signal strength (dBmV) Signal noise ratio (dB) Channel ID
1 663000000 256QAM -2.300 38.605 11
2 591000000 256QAM -2.700 38.605 13
3 597000000 256QAM -2.400 38.983 1
4 603000000 256QAM -2.200 38.605 2
5 609000000 256QAM -2.700 38.605 3
6 615000000 256QAM -2.600 37.636 4
7 621000000 256QAM -2.100 38.605 5
8 633000000 256QAM -3.000 37.636 6
9 639000000 256QAM -2.700 37.636 7
10 645000000 256QAM -2.400 37.636 8
11 651000000 256QAM -2.600 37.356 9
12 657000000 256QAM -2.700 37.636 10
13 669000000 256QAM -2.400 37.636 12
14 675000000 256QAM -2.900 37.636 14
15 681000000 256QAM 4.200 40.366 15
16 687000000 256QAM 4.200 40.946 16
17 693000000 256QAM 4.200 40.946 17
18 699000000 256QAM 4.000 40.946 18
19 705000000 256QAM 4.300 40.366 19
20 711000000 256QAM 4.300 40.946 20
Upstream Overview
Port ID Frequency (MHz) BandWidth Modulation Type Signal Strength (dBmV) Channel ID
1 30596000 6400000 ATDMA 45.750 2
2 23700000 6400000 ATDMA 45.750 3
3 38596000 3200000 ATDMA 47.250 1

© 2013 Hitron Technologies Inc.. All rights reserved.


--------------------------------------------------

 

After reboot

Downstream Overview  ~ Speedtest (Rogers) 78.29mbps down 7.98mbps up
Port ID Frequency (MHz) Modulation Signal strength (dBmV) Signal noise ratio (dB) Channel ID
1 663000000 256QAM -2.200 38.605 11
2 591000000 256QAM -2.700 38.605 13
3 597000000 256QAM -2.400 38.605 1
4 603000000 256QAM -2.200 38.605 2
5 609000000 256QAM -2.600 38.605 3
6 615000000 256QAM -2.600 37.636 4
7 621000000 256QAM -2.100 38.983 5
8 633000000 256QAM -2.900 37.636 6
9 639000000 256QAM -2.600 37.636 7
10 645000000 256QAM -2.400 37.636 8
11 651000000 256QAM -2.500 37.636 9
12 657000000 256QAM -2.700 37.636 10
13 669000000 256QAM -2.300 37.636 12
14 675000000 256QAM -2.800 37.356 14
15 681000000 256QAM 4.300 40.946 15
16 687000000 256QAM 4.300 40.946 16
17 693000000 256QAM 4.200 40.946 17
18 699000000 256QAM 4.100 40.366 18
19 705000000 256QAM 4.300 40.366 19
20 711000000 256QAM 4.400 40.366 20
Upstream Overview
Port ID Frequency (MHz) BandWidth Modulation Type Signal Strength (dBmV) Channel ID
1 38596000 3200000 ATDMA 46.250 1
2 23700000 6400000 ATDMA 46.000 3
3 30596000 6400000 ATDMA 46.250 2

 

CGN3 is a rental!
--------------------------------

Antron 2 way splitter ~ -3.5db

-------------------------------

HW Version 1A
SW Version 4.2.4.3
WAN Receiving 138.27M Bytes
WAN Sending 4.69M Bytes
LAN Receiving 4.98M Bytes
LAN Sending 141.33M Bytes

 

 

***edited labels***

1 ACCEPTED SOLUTION

Accepted Solutions

Re: Possible CGN3 issue - need the pro's to look at the stats

@netwrks, just to be sure I have this correct, you were running your own router with the CGN3 in bridge mode when you noticed the slowdowns, so, based on that, you have some type of cable or data feed issue. After bringing home a second CGN3, I’d say that you have ruled out the possibility that it’s the modem that is at fault.   Did you change the power brick as well? There has been the odd case where it was overheating, causing the modem to shut down and restart. So, if you changed the modem, you should have also changed the power brick.

 

As RogersMoin indicated, your signal levels and signal to noise ratios are all within spec, but I would raise the issue of the jump in power levels for the final 6 channels. There is a 7.2 dBmV jump, upwards from the previous channels, which is unusual to see. The output from the node is normally ramped up, as the signal frequencies go up, so does the output level. This is to counteract the drop in cable signal levels which go the other way, as you go up in frequency, the losses increase, so between the two of those, by the time the signal reaches your home, the levels should be flat or possibly have a very very small ramp up or down depending on the distance to the node and the condition of the cabling. That is one issue that I would raise with tech support.

 

When your internet speed drops to nothing, does the modem stay online or does it decide to reboot at any time? A reboot would indicate a potential cable problem, with the modem attempting a reboot to re-establish comms with the node. When the modem speed drops to zero and stays there, do you have enough time at that point to call tech support? That is probably the most ideal time to call, when there is an issue in progress, so that the CSR can check the modem and the neighbourhood node to look for the source of the problem. Put tech support on speed dial and call in when this occurs. I suspect that your neighbours might be experiencing the same issue, unless this is solely due to a cable problem between your home and the local tap.

 

If you are new to the CGN3, here is some background info on the CGN3 that you should know for your troubleshooting.

 

If you have firmware version 4.2.4.3 loaded, you can run into throttling problems. There is a bug in that CGN3 firmware version which throttles the download rates for directly connected devices, where those devices are 10/100 Mb/s only.  You can confirm this by looking at the back of the CGN3 to determine what colour the port LED indicates.  If its amber, the interconnect rate with the device is 1 Gb/s and you should not have any issues with throttled download rates.  If the LED is green, the interconnect rate is 10/100 Mb/s and you will end up with throttled download rates.  That can be the result of either the device port that is connected or/and the ethernet cable that is used, as is might not support higher data rates as well. While the port will be running at 100 Mb/s, the maximum data rate through the modem will be limited to 35 Mb/s. Firmware version 4.2.4.5, which is already out, resolves this issue. That version should be uploaded to your modem within 48 hours, although I would give it three to four days for it to show up. After that, you can call tech support to raise a ticket to have it pushed out to the modem.

 

The CGN3 does not support mixed 20 Mhz / 40 Mhz environments on its 2.4 Ghz networks. To run higher data rates, routers and devices use channel bonding on 2.4 Ghz networks to run two 20 Mhz wide channels together and push more data. Most but not all routers support mixed environments where you have some devices that can do that and some that can’t. The CGN3 does not support a mixed environment and it will throttle down to the slowest device on the network. So if that happens to be a single channel device, then your dual channel laptops and tablets will only be able to use a single channel and as a result will appear to be running slower than what you would expect. The same can be said for single data stream versus dual data stream devices. Laptops are typically dual antenna, dual data stream devices. Some devices only have a single antenna, therefore only support a single data stream. The CGN3 will lock down to single antenna, single data stream data rates if there happens to be a single antenna device operating on the network. Also note, the CGN3 is not certified for concurrent 2.4 and 5 Ghz networks. The Wifi Alliance certificate only shows one or the other. Take that into consideration when you are looking at wifi issues with the CGN3. I can attest that it runs really well with just the 5 Ghz network running. 

 

If you suspect that you are encountering wifi issues, the way to check your wifi environment is by loading inSSIDer on a laptop and checking the network display. That display will show you how many other routers are running nearby and whether or not any of them are running on the same channel and causing problems for you. If you can post a screen capture somewhere, that really helps when it comes to diagnosing wifi issues. Here is the link to the last freebie version of inSSIDer. It does not do 802.11ac, which is becoming more prevalent these days, so my advice to anyone who really wants to continue using inSSIDer is to spend the $20 to buy the latest version. You might be amazed to see how many people are using 802.11ac nearby. You don’t need an 802.11ac laptop as the header data shows the transmission type, and that can be read and displayed by a non 802.11ac laptop.

 

http://www.techspot.com/downloads/5936-inssider.html

 



View solution in original post

9 REPLIES 9

Re: Possible CGN3 issue - need the pro's to look at the stats

RogersMoin
Moderator
Moderator

Hello @netwrks, Welcome to the Rogers Community Forum! Sorry for the inconvenience you are facing with the speed. The Signal Strength and Signal to Noise Ratio is ok, within acceptable range.

 

In order to fully understand the issue, would you please clarify the following questions:

 

  • Speed drops to almost zero at certain times, and then comes back to normal?
  • Or once it drops it stays there?
  • Is the splitter mentioned installed by Rogers’s tech?
  • Do you use a surge protected power bar for Coax and to power up CGN3 or any power bar to power up the modem?

Firmware is not the issue; however it will get updated to 4.2.4.5

 

Thanks,

RogersMoin

Re: Possible CGN3 issue - need the pro's to look at the stats

netwrks
I Plan to Stick Around
  • Speed drops to almost zero at certain times, and then comes back to normal? I  was describing the upload speed using ookla or Rogers speed test.
  • Or once it drops it stays there? Yes once the upload drops it stays there.
  • Is the splitter mentioned installed by Rogers’s tech? The spliter is an Antron splitter supplied and installed by Rogers.
  • Do you use a surge protected power bar for Coax and to power up CGN3 or any power bar to power up the modem? No surge protector with coax and no power bar for router.

 

Re: Possible CGN3 issue - need the pro's to look at the stats

netwrks
I Plan to Stick Around

For giggles I thought I would run speed test using Rogers Speedtest and it's ok, once again. This time I ran it over wireless. Just in case anyone might ask.. this morning's test were done directly connected to the router via a 10'  CAT6 cable.

 

download - 75.55 mbps

upload - 11.5mbps.

 

DOCSIS stats are the same as the second stats I copied. So.. is it the connection or the CGN3?

 

Re: Possible CGN3 issue - need the pro's to look at the stats

The connection is a little on the low side signal wise (should be as close to 0 as you can) but not horrible.. not enough that it should be causing that issue.

Re: Possible CGN3 issue - need the pro's to look at the stats

@netwrks, just to be sure I have this correct, you were running your own router with the CGN3 in bridge mode when you noticed the slowdowns, so, based on that, you have some type of cable or data feed issue. After bringing home a second CGN3, I’d say that you have ruled out the possibility that it’s the modem that is at fault.   Did you change the power brick as well? There has been the odd case where it was overheating, causing the modem to shut down and restart. So, if you changed the modem, you should have also changed the power brick.

 

As RogersMoin indicated, your signal levels and signal to noise ratios are all within spec, but I would raise the issue of the jump in power levels for the final 6 channels. There is a 7.2 dBmV jump, upwards from the previous channels, which is unusual to see. The output from the node is normally ramped up, as the signal frequencies go up, so does the output level. This is to counteract the drop in cable signal levels which go the other way, as you go up in frequency, the losses increase, so between the two of those, by the time the signal reaches your home, the levels should be flat or possibly have a very very small ramp up or down depending on the distance to the node and the condition of the cabling. That is one issue that I would raise with tech support.

 

When your internet speed drops to nothing, does the modem stay online or does it decide to reboot at any time? A reboot would indicate a potential cable problem, with the modem attempting a reboot to re-establish comms with the node. When the modem speed drops to zero and stays there, do you have enough time at that point to call tech support? That is probably the most ideal time to call, when there is an issue in progress, so that the CSR can check the modem and the neighbourhood node to look for the source of the problem. Put tech support on speed dial and call in when this occurs. I suspect that your neighbours might be experiencing the same issue, unless this is solely due to a cable problem between your home and the local tap.

 

If you are new to the CGN3, here is some background info on the CGN3 that you should know for your troubleshooting.

 

If you have firmware version 4.2.4.3 loaded, you can run into throttling problems. There is a bug in that CGN3 firmware version which throttles the download rates for directly connected devices, where those devices are 10/100 Mb/s only.  You can confirm this by looking at the back of the CGN3 to determine what colour the port LED indicates.  If its amber, the interconnect rate with the device is 1 Gb/s and you should not have any issues with throttled download rates.  If the LED is green, the interconnect rate is 10/100 Mb/s and you will end up with throttled download rates.  That can be the result of either the device port that is connected or/and the ethernet cable that is used, as is might not support higher data rates as well. While the port will be running at 100 Mb/s, the maximum data rate through the modem will be limited to 35 Mb/s. Firmware version 4.2.4.5, which is already out, resolves this issue. That version should be uploaded to your modem within 48 hours, although I would give it three to four days for it to show up. After that, you can call tech support to raise a ticket to have it pushed out to the modem.

 

The CGN3 does not support mixed 20 Mhz / 40 Mhz environments on its 2.4 Ghz networks. To run higher data rates, routers and devices use channel bonding on 2.4 Ghz networks to run two 20 Mhz wide channels together and push more data. Most but not all routers support mixed environments where you have some devices that can do that and some that can’t. The CGN3 does not support a mixed environment and it will throttle down to the slowest device on the network. So if that happens to be a single channel device, then your dual channel laptops and tablets will only be able to use a single channel and as a result will appear to be running slower than what you would expect. The same can be said for single data stream versus dual data stream devices. Laptops are typically dual antenna, dual data stream devices. Some devices only have a single antenna, therefore only support a single data stream. The CGN3 will lock down to single antenna, single data stream data rates if there happens to be a single antenna device operating on the network. Also note, the CGN3 is not certified for concurrent 2.4 and 5 Ghz networks. The Wifi Alliance certificate only shows one or the other. Take that into consideration when you are looking at wifi issues with the CGN3. I can attest that it runs really well with just the 5 Ghz network running. 

 

If you suspect that you are encountering wifi issues, the way to check your wifi environment is by loading inSSIDer on a laptop and checking the network display. That display will show you how many other routers are running nearby and whether or not any of them are running on the same channel and causing problems for you. If you can post a screen capture somewhere, that really helps when it comes to diagnosing wifi issues. Here is the link to the last freebie version of inSSIDer. It does not do 802.11ac, which is becoming more prevalent these days, so my advice to anyone who really wants to continue using inSSIDer is to spend the $20 to buy the latest version. You might be amazed to see how many people are using 802.11ac nearby. You don’t need an 802.11ac laptop as the header data shows the transmission type, and that can be read and displayed by a non 802.11ac laptop.

 

http://www.techspot.com/downloads/5936-inssider.html

 



Re: Possible CGN3 issue - need the pro's to look at the stats

netwrks
I Plan to Stick Around

@Datalinks In my current set up I am running the CGN3 in router mode - all wireless on the CGN3 is configured off. The only thing I am running on the CGN3 is DHCP. It is serving IP's to my environment.

 

I run a CAT6 uplink from the CGN3 to a Netgear R7000. Uplink is at 1000mbps (amber). Netgear is in AP mode.  Both devices are about 40 feet apart.  In either bridged or router mode on the CGN3 I can create the symptom.

 

Like I mentioned yesterday, when I did the original test's wirelessly, I disabled wifi on my laptop and plugged directly into the CGN3's ethernet port, with a 10 foot CAT6 RJ45 cable and ran the speedtest's. The two tests I posted were conducted wired.

 

When running the speedtest, and, when the upload stalls, the CGN3 is up and running! This morning the speedtest's are working fine. I am going to try swapping the power brick, as the original brick is still plugged in..

Just swapped out the power brick. WAN Stats below. I will open a ticket with Rogers and keep an eye out for the new firmware release..

 

Downstream Overview
Port ID     Frequency (MHz)     Modulation     Signal strength (dBmV)     Signal noise ratio (dB)     Channel ID
1    603000000     256QAM     -2.200    38.983    2
2    591000000     256QAM     -2.700    38.605    13
3    597000000     256QAM     -2.400    38.605    1
4    609000000     256QAM     -2.700    38.983    3
5    615000000     256QAM     -2.600    37.356    4
6    621000000     256QAM     -2.100    38.605    5
7    633000000     256QAM     -2.900    37.356    6
8    639000000     256QAM     -2.700    37.356    7
9    645000000     256QAM     -2.500    37.636    8
10    651000000     256QAM     -2.600    37.636    9
11    657000000     256QAM     -2.800    37.636    10
12    663000000     256QAM     -2.300    38.605    11
13    669000000     256QAM     -2.400    37.356    12
14    675000000     256QAM     -2.900    37.636    14
15    681000000     256QAM     4.200    40.946    15
16    687000000     256QAM     4.200    40.946    16
17    693000000     256QAM     4.100    40.946    17
18    699000000     256QAM     3.900    40.366    18
19    705000000     256QAM     4.200    40.946    19
20    711000000     256QAM     4.200    40.366    20
Upstream Overview
Port ID    Frequency (MHz)    BandWidth    Modulation Type    Signal Strength (dBmV)    Channel ID
1    38596000    3200000    ATDMA    46.250    1
2    23700000    6400000    ATDMA    46.250    3
3    30596000    6400000    ATDMA    46.250    2

 

 

Re: Possible CGN3 issue - need the pro's to look at the stats

Good eyes datalink.. i missed that in the original signal posting.

I agree.. while within spec... normally the signal strength is overall in the same range.. you would have -2ish across the board... that you have +4 on the last 6 channels or so.. is VERY odd.

I would likely think.. that there is a signal issue in some way.. its allowing (or not allowing) all the proper signal through evenly across the board.  Some frequencies might be and some not.

 

Overall, i would PUSH to see if you can get a tech out.. get them to look at thing, swap out most of the connectors/splitters, to see if the signal will ballance out.

Re: Possible CGN3 issue - need the pro's to look at the stats

netwrks
I Plan to Stick Around

Hi again - last Thursday it was suggested that I woud see a FW upgrade (to 4.2.4.5) withing 48 hours, on the CGN3. As of this morning, I am still running on 4.2.4.3, Is Rogers still pushing out this update?

Re: Possible CGN3 issue - need the pro's to look at the stats

Call tech support and ask them to have it pushed out to your modem.  Have you already asked tech support about the discontinuity in your downstream signal levels?



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