Very slow internet speeds (CGN3)

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I Plan to Stick Around
Posts: 16

Re: Very slow internet speeds (CGN3)

Thanks for the explanations. As far as lights are concerned i have As far as light are concerned link to my desktop and external drive are orange, and the link to my media device (WD TV Live) is green. As you said Wi-Fi printer does not work when connected to the CGN3.I use power bar, but in order to plug modem directrly to the outlet on the wall I have to do some serious rearangements and will try later when I get time.


Do you suggest that I plug another Wi-Fi router and use that one for switch and Wi-Fi connection and use CGN3 ONLY as a modem?


It boggles my mind that the company of the size and market share like Rogers would put such a faulty product without even advising customers about all these issues and still inacurately advertise and charge top dollar for it. .


Thanks again for all your help



Here are my tables:

Downstream Overview
Port ID     Frequency (MHz)     Modulation     Signal strength (dBmV)     Signal noise ratio (dB)     Channel ID
1    651000000     256QAM     -6.100    37.356    82
2    591000000     256QAM     -6.400    37.636    73
3    597000000     256QAM     -6.700    37.356    74
4    603000000     256QAM     -5.700    37.636    75
5    609000000     256QAM     -5.800    37.356    76
6    615000000     256QAM     -7.200    36.387    77
7    621000000     256QAM     -7.500    36.387    78
8    633000000     256QAM     -5.700    36.387    79
9    639000000     256QAM     -6.900    36.610    80
10    645000000     256QAM     -6.900    36.610    81
11    657000000     256QAM     -5.800    37.356    83
12    663000000     256QAM     -6.500    37.636    84
13    669000000     256QAM     -6.700    37.356    85
14    675000000     256QAM     -6.600    37.356    86
15    681000000     256QAM     -6.900    37.356    87
16    687000000     256QAM     -6.900    37.356    88
17    693000000     256QAM     -6.000    37.356    89
18    699000000     256QAM     -5.300    37.636    90
19    705000000     256QAM     -5.100    37.636    91
20    711000000     256QAM     -4.700    37.636    92
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    43.250    3
3    30596000    6400000    ATDMA    44.750    2


Resident Expert
Resident Expert
Posts: 7,368

Re: Very slow internet speeds (CGN3)

Ok, this is going to be a long post……to do list is at the end.


Your Downstream power levels while still in spec are low and your Upstream levels, also still in spec, are elevated. That usually translates into a cable or connector problem of some type. The target levels are 0 dBmV on the Downstream side, with Signal to Noise ratios in the 36 to 40 dB range and 36 to 40 dBmV on the Upstream side. So, still in spec but not where they should be. I would call tech support with the aim of getting a tech out to your home to check the cable and connectors.


What you could do temporarily is use an extension cord with a number of outlets on it. Hopefully that will provide enough plug-in points for test purposes to run your computers, monitors and modem. The point about the power bar is to be able to unplug it completely in case it turns out to be an RF noise source. At the same time, if your RG6 feed cable or your ethernet cable runs through it, unplug them and go direct, wall RG6 outlet to modem and modem to devices for the ethernet. There can be problems with impedance matching and signal losses for the RG6 cable and problems with signal losses for the ethernet cable when you use a surge suppresser. So, with direct connections, one can establish a baseline set of signal power and speedtest results. With those numbers on hand, you can tell if connecting through anything results in a drop from the original results. Having said all of that, note that I indicate this is for power bars, and not for an Uninterruptible Power Supply (UPS) in terms of power only. If you do connect the RG6 through the power bar or UPS to use its surge suppression capabilities, unplug it and go direct and have a look at the power levels and run a speedtest to look for any differences before deciding to call tech support.  If you did bring in tech support and the issue turned out to be with a power bar or surge suppresser, you would most likely end up paying for the call as it was a customer equipment fault.


Your WD TV Live is an interesting case. There is no doubt that it will probably only draw about 35 Mb/s maximum due to the throttling effect of the bug within the CGN3. Does that cause any issues for your streaming media? Only you can tell. Do you happen to notice any stuttering on video or audio for any device? There are two ways to deal with this. The first is to buy and connect a gigabit switch to the CGN3 and then connect any 10/100 Mb/s devices to the switch. The fact that the Port LED for the WD TV Live is Green tells you that this device has a 10/100 Mb/s port on it, or possibly that the connecting cable is faulty and only using 2 out of the 4 wire pairs in the ethernet cable. The Port can’t distinguish between either case. Reading online in the WD Community, it would seem that the spec is not clear and that the device, if it has a gigabit port is not utilizing that capability and is limited to 10/100 Mb/s. A quick scan through the manual doesn’t find any mention of the port.


The second way to deal with this is to buy a gigabit port equipped router. That will accomplish the same thing and it will also give you much better wifi capability. To be fair, a modem / router combo with internal antenna will not match the wifi transmit / receive performance of a good wifi router with external antenna. There are a couple exceptions of course for enterprise equipment, but personal opinion, external antenna is the way to go. There a couple of ways to connect to a third party router, one is to run the CGN3 in Bridge mode and use the router for everything. Two: run the CGN3 in Gateway mode and turn off the wifi and use the wifi on the router. This gives you access to the CGN3 ports as well as the ports on the router. If you had structured wiring in your house, that would also allow you to park the router somewhere else in the house where you might normally use your wireless devices.


Ok, on to the devices. Your desktop download rate is really low, to the point of looking like a throttled rate. Can you drill down in to the devices listing on your pc and find out what ethernet controller you have on the motherboard? Its strange that you reported a higher rate earlier and now it has dropped.  It might the result of a combination of issues, including the Downstream & Upstream signal power. Does your laptop have a gigabit ethernet port, and if so, can you run a speedtest with it? The CGN3 port LED colour will let you know if its gigabit capable.


Your Iphone download rate is also very low. So, here’s a couple of questions:


1. What networks are you running for those devices and which network supports which device?


2. If you run both 2.4 and 5 Ghz networks and use the same SSID for both, rename one of them so that you know which one is the 2.4 and which one is the 5 Ghz networks. If they have the same name, you can end up with connections to one of them while you believe that the other network is in use. Same SSIDs can cause confusion for the device and the user. Keep in mind that the 2.4 Ghz network will be better for range, while the 5 Ghz can deliver a higher data rate at a shorter range. What network you choose to support the devices will depend on where the modem is located and where these devices are typically used.  Looking at the Apple site, it looks like all of the Ipads support both 2.4 and 5 Ghz. You would have to check the specs for your Iphone and laptop to see what frequency they support for wifi networks.


3. Did you by any chance use the USB setup drive that came with the CGN3, and if so, did you use it to setup a guest account? If so, please read through this thread. The problems caused by the USB setup key will make themselves clear as you read through it. This applies to both the CGN2 and CGN3.


Ok, so, here’s the list:

1. Disconnect the power bar, for both power and cable and go direct for the cable

2. Look at the power levels and speedtest results again.

3. No improvement, call tech support. Please post tables, speedtest results again as well

    as motherboard ethernet controller manufacturer and model.

4. Run a wired speedtest with your laptop if possible.

5. Look at your network SSIDs for same names

6. Look at the issues caused by the USB setup key

7. If you fall into the category of #6, exchange your CGN3 and do not use the USB setup

    key on the next modem. And, if you are in this category and you happen to use the 2.4

    Ghz network for your devices, setup the next modem, and monitor the wireless network

    with inSSIDer an indicated in the other thread. When and if you are satisfied that the

    network(s) are running as they should, run some speedtests to see where you are at.

8.  Consider a gigabit switch or new wifi router, depending on #6 and #7



I Plan to Stick Around
Posts: 16

Re: Very slow internet speeds (CGN3)

I cannot say enough thanks for your efforts helping!


It is qite a list and i have to take whole day to do it and I will.


Will post results!


Again thanks a Million!




Resident Expert
Resident Expert
Posts: 7,368

Re: Very slow internet speeds (CGN3)

Here's one possible shortcut.  If you have ever, at any time, set up a guest wireless network using the Setup USB Drive that comes with the CGN3, return the CGN3 and exchange it for a new one.  Even if you had turned off the guest network, there is most likely a ghost 2.4 Ghz network being transmitted by the CGN3 as well as your real network.  That cuts your transmitted power for your intended network in two even if the guest network was turned off, and cuts the power in three if in fact your guest network is still running.  No amount of factory resets will turn off the ghost network.  That is one additional reason for poor wifi performance, on top of only having internal antenna, wifi interfererence from neighbours and the fact that handheld devices themselves might not be great when it comes to wifi performance.  So, if you are in that position, return the CGN3 and setup the next one without using the Setup USB Drive.  If you really require a guest network capability, you will have to bite the bullet and buy a wifi router to do the job. 


As an example of handheld performance, using the 5 Ghz wifi on the CGN3 with a 250 Mb/s plan, the best I've ever seen is 200 Mb/s down, 20 Mb/s up with a very capable gaming laptop, compared to 50 Mb/s down and 20 Mb/s up with a Windows RT tablet.  So, although the CGN3 can run much faster, (not as fast as a good wifi router) the tablet can't support higher rates.  Keep that in mind in looking at your Iphone, Ipad and laptop rates.  I would expect your laptop to run at wireless rates as high as 200 Mb/s which is where the Rogers Speedboost will probably max out at with your plan.  The laptop we have is 802.11ac capable, so it will run much faster, but the CGN3 doesn't appear to able to run any faster from what I can see so far.

I Plan to Stick Around
Posts: 16

Re: Very slow internet speeds (CGN3)

Yeah I can do that. And I will tomorrow. I did try USB settup (which did not work anyways). Let's see if that fixes the problem


As usual Thank you again.


I'm Here A Lot
Posts: 5

Re: Very slow internet speeds (CGN3)

Intermittency Issue/Super Slow Speed (Tech Support Couldn't Fix It)


Hey guys. You guys are my last resort. Please bare with me because I have to explain everything that's happening.

I am currently directly connected to the modem. Both wired and wireless devices are having the same issue. My modem is called Hitron CGN3ACR. 

So about a month or so ago I moved from a 30mbps connection to a 100mbps (new modem) and everything was working perfectly for about a week. Then started having connection issues. Some times the internet connection would get disconnected and then come back after half an hour. And most of the time, I would get about 5 mbps out of 100.

I called my Rogers like 10 times and every-time they would make me reset the modem or they would reset it remotely but nothing worked. They sent a technical support guy who looked at the Rogers box at my backyard and said he removed the filter (when he came, the connection was fine..). Things worked for a day and same thing started happening.

After calling Rogers, they said they will send a team to my area. After a day or 2, I get a text from the team that gave me a ticket number and said to talk to customer support. Still no solution.

So I was gonna cancel the service. When I called technical support, they said the last thing I should try is get a new modem. So I did.

Now here's the weird part, now the internet connection stays connected but the speed issue is worse. Yesterday, for almost the whole day I got about 40 kbps download speed. When I called customer support, they said the signal from the modem looks good (they said the same thing the last 10 times too). They asked me to give them another chance. They sent another tech guy to my house but just my luck, the internet connection was working perfectly. He said he would not be able to identify the issue if he can't see it when its happening.

Now I honestly don't know what to do. The other provider in my area offers only 10mbps max so moving to them isn't an option. I would really appreciate your help. The tech guy just left and things are working perfectly. I'm making this post using the internet but I know it will slow down soon. You guys are my last hope.

More Info:

Operating systems: Windows 7, Ios, OSX Yosemite
Connection type: Both wired and wireless having the issue
Modem: Hitron CGN3ACR
Router: None

Thank you in advance!

Resident Expert
Resident Expert
Posts: 7,368

Re: Very slow internet speeds (CGN3)

Ok, just for starters, can you log into the modem, navigate to STATUS,..... DOCSIS WAN, copy the downstream and upstream tables and paste them into this thread.  Those are the cable signal levels which are usually worth examining.  Can you also describe in general, your LAN, ie:  Modem....Router....2 Wired PCs + wireless laptop + etc. etc, in general what you have and how it connects to each other.  Please indicate whether you use commercial Cat 5e cables for example or house ethernet cabling, which can make a difference in how its installed.


Can you also indicate if you have other Rogers services such as Home phone or one or more NB2s / NB3s, as that would require one or more splitter or an amplifier.

I'm Here A Lot
Posts: 5

Re: Very slow internet speeds (CGN3)

Thanks for your reply. 


I currently only have internet with Rogers. I forgot to mention one thing though. When everything is working perfectly, even though the speed tests are showing full speed, most of the time when I actually download a file I only get 15-20mbps speed (i tried reliable sites so not a host issue).




No router.


Wired Devices: 2 PCs using windows 7, 1 iptv (Ethernet cables)


Wireless Devices: 2 iPhone 5, 1 Macbook pro (using Yosemite), 1 iPad 2 and 1 iPad 4, another iptv 


By Cat 5e, do you mean the ethernet cables? If so, I'm using 1 that came with the rogers modem and 2 from stores. 


Here is the table data you requested (copied when the speed test was "normal" but downloading was only 15-20mbps using mutiple browsers; chrome and IE). Thank you.


Downstream Overview
Port IDFrequency (MHz)ModulationSignal strength (dBmV)Channel IDSignal noise ratio (dB)
Upstream Overview
Port IDFrequency (MHz)ModulationSignal strength (dBmV)Channel IDBandWidth
130596000ATDMA - 64QAM44.75026400000
223700000ATDMA - 64QAM44.75036400000
338596000ATDMA - 64QAM44.75013200000
Resident Expert
Resident Expert
Posts: 7,368

Re: Very slow internet speeds (CGN3)

Your Downstream levels and signal to noise ratios are really good.  The upstream levels are a little above their 36 to 40 dBmV range, but with those levels I wouldn't expect you to have any problems with connection rates, down or up.  When you run a speed test, do you use wired or wireless connections?  Unless you have a good third party router, and know that your wifi devices support data rates that are above the wired speeds, you really can't trust speedtests via wifi to judge whether or not the modem is functioning correctly from a cable data rate perspective.   Can you run a couple of wired speedtests using and using the Toronto Telus server and post the peak results that you see during the tests?  With that info, I'll have a better idea of what you are seeing from your modem and what the modem will deliver via wired connection.  On a 100/10 Mb/s service I'd expect to see something like ~130 Mb/s down with Speedboost kicking in, 10 to 11 Mb/s up.  Ping times will probably be in the 12 ms or less range.


When you indicated that you are seeing slower download rates from websites, are those downloads via wired or wireless connection?  If those are thru a wifi connection, that brings a number of variables into the equation, starting with wifi performance of the modem, which works, but isn't great.  There is also the issue of download rates available from websites, whether it be via direct download or ftp.  I don't think I know of any site that will give you sustained downloads at something like 100 Mb/s or more throughout a large download.  I'm just wondering how you are running the downloads, wired or wireless, and possibly if you're expecting the download rates to match speedtest rates that you see?

I'm Here A Lot
Posts: 5

Re: Very slow internet speeds (CGN3)

Sorry about the late reply. We went on vacation and still having the same issues.

I always do speedtests using wired connection. I also used wired while downloading.

I  tried Steam and The game clients (they are very reliable). 

The speed tests are showing 100+ mbps but guess what, in reality even this forum isn't even loading. It doesn't matter what the speedtests are showing, I don't even get 5mbps when I actually use it.

The technicians came to my house twice and even they said, Rogers won't even do anything to fix the issue as long as the speetests are showing "High Speed". They kept saying the signal looks good from their end.. like then why am I calling you? I called them 20 times (i'm not even joking lol)

I finally called bell and switching to them next week. I'll be paying the same price but only get 15mbps. At least it's better than 5mbps and tech guys treating me like a kid by resetting the modem 10 times.
Hopefully this message doesn't get deleted..

But I do appreciate your help. Thanks for taking the time to help me.