@Qubit personal opinion, your downstream signal levels are too high. The target level is 0 dBmV with a signal to noise ratio typically in the 36 to 40 dB range. The one unanswered question is how much data, if any is transmitted by the QAM channels (1 to 32) compared to the three OFDM channels that are running. If there's no useful data transmitted by the QAM channels, then your signal levels might be ok for sake of running the OFDM channels. If these levels were showing up on my modem I'd be looking to drop them back down to 0 dBmV.
It appears that Rogers has widened its definition of acceptable signal levels. Your signal levels, in the past would have failed an automated signal level check, and as a result, you would have seen a tech arrive to sort out the issue. I suspect that Rogers, today, won't do anything to address those levels. Historically, on the Rogers network, customers with downstream signal levels outside of +/- 6/7 dBmV would typically seen problems with their internet service. The modems have an operating range of +/- 15 dBmV, but, customers usually see problems long before those limits are ever reached.
Can you have a look at the location where the external cable enters your house. I'm assuming that you're in a house, but, please correct me if I'm wrong. Where the external cable connects with the internal cable running to your modem, you should see an F-81 connector which looks like this:
https://www.homedepot.ca/product/ideal-3ghz-f-splice-adapter-10-pack-/1000751479
There should not be a powered amplifier or a splitter of any type that connects the external cable to the internal cable, and, there should not be any of the other house RG-6 cables connected to either the amplifier or splitter. What you should see is the inbound external RG-6 cable connecting to the F-81 connector, which connects to the internal RG-6 cable leading up to the modem. That's it. Any of the other RG-6 cables should disconnected and moved out of the way.
Please let me know what you find.
Can you also post the upstream signal levels and the word correctable/uncorrectable table as well.
@TECHHEAD great post! Removing those splitters would have increased the downstream signal levels by 7 dB, and dropped the upstream signal levels by 7 dB. Both of those are good, but, the question now is whether or not the downstream signal levels are too high?
When you have time, can you post the downstream and upstream signal levels and Word table?
The external Network Interface Device (grey enclosure) typically holds a ground block which is connected to the inbound cable from the local tap and the outbound cable which runs to the house cable entry point. The local tap is either mounted on a nearby utility pole or within a green coloured pedestal which should be visible from your front door if you happen to have underground cabling. The NID requires a tool to open, however it is possible to back the enclosure screw off, to the point that it will open. Its a long screw that secures the case of the NID. I'm not advocating opening the NID.
If you simply look at the bottom and back of the NID, you should see two RG-6 cables as described above plus a copper ground cable that is usually connected to a clamp which attaches to the hydro meter box. If you have a newer home with installed cabling, there shouldn't be any splitter within the NID, as there is only one cable required to run from the ground block to the internal cable drop point. If you see other cables exiting the NID, then there is most likely a splitter within the NID. That would happen with older homes which don't have an internal cable system. The techs would run the cables on the outside of the house and drill thru the external walls to bring the cable indoors. If you're running the Ignite TV system, with the XB6, XB7, or XB8 modem, and the system was installed by a tech, any splitter within the NID should have been removed and replaced with an F-81 connector to connect the inbound cable from the local tap to the outbound cable which runs into the home. Only way to find out however is to open the NID and check the contents. There should be a cable ground block, connected cables and no splitter.
So, as I indicated above, great post. Its nice to see that every once in a while I manage to post something that appears to have a positive impact on a troublesome internet system 🙂 Guess I'll have to amend those statements to include an inspection for any splitters that might be found anywhere along the cable run, from the basement connector location, up to the point that the cable disappears into the floor or wall. There should be no splitters anywhere along the path, from the inbound cable connection point, up to the modem.
@Qubit sorry to get back to you so late. Obviously I missed your post. Your upstream signal levels look ok. The codeword table for the most part is very good. There's no uncorrected Codewords which is good to see. There are correctable Codewords showing for Channel 1 which is a QAM channel. I wonder if that's due to the OFDM channel which is running within that same bandwidth. The only odd item is the corrected codewords for channel 33 which is a low powered OFDM channel. The corrected codewords are about half of the total number of codewords. Thats rather unusual. Its good that there isn't any uncorrected codewords, but, its a little unusual to see the codeword number as high as its showing.
Can you have a look at the location where the inbound external cable enters the home. Where the external cable connects with the internal cable running to your modem, you should see an F-81 connector which looks like this:
https://www.homedepot.ca/product/ideal-3ghz-f-splice-adapter-10-pack-/1000751479
There should not be a powered amplifier or a splitter of any type that connects the external cable to the internal cable, and, there should not be any of the other house RG-6 cables connected to either the amplifier or splitter. What you should see is the inbound external RG-6 cable connecting to the F-81 connector, which connects to the internal RG-6 cable leading up to the modem. That's it. Any of the other RG-6 cables should disconnected and moved out of the way. I'm thinking in your case that there might be a powered amplifier at that connection point.
Also, have a look for any splitters that might be found anywhere along the cable run, from the basement connector location, up to the point that the cable disappears into the floor or wall. There should be no splitters anywhere along the path, from the inbound cable connection point, up to the modem.
Please let me know what you find.
Have you contacted any of the moderators at @CommunityHelps regarding the problems that you're experiencing?
@Datalink wrote:
@Qubit sorry to get back to you so late. Obviously I missed your post. Your upstream signal levels look ok. The codeword table for the most part is very good. There's no uncorrected Codewords which is good to see. There are correctable Codewords showing for Channel 1 which is a QAM channel. I wonder if that's due to the OFDM channel which is running within that same bandwidth.
On the Ignite gateways, the error stats shown on Index 1 are the same as those shown on Index 34. I never looked into why but it has always been this way with every Ignite gateway that I have had. (Back when we were provisioned with only one downstream OFDM channel, there was never any need to scroll to the end of the table to see the error stats.)
@Qubit Your upstream power levels are a bit high but your signal levels are otherwise okay.
We usually recommend removing splitters to keep the installation clean. However, in your case, the tech probably needed a 3 dB attenuator to bring your signal levels to acceptable levels... but they don't carry any such thing in their truck... so what they do is install a splitter, terminate the unused output(s) and voilà; problem solved.
@Datalink wrote:@TECHHEAD great post! Removing those splitters would have increased the downstream signal levels by 7 dB, and dropped the upstream signal levels by 7 dB. Both of those are good, but, the question now is whether or not the downstream signal levels are too high?
When you have time, can you post the downstream and upstream signal levels and Word table?
The external Network Interface Device (grey enclosure) typically holds a ground block which is connected to the inbound cable from the local tap and the outbound cable which runs to the house cable entry point. The local tap is either mounted on a nearby utility pole or within a green coloured pedestal which should be visible from your front door if you happen to have underground cabling. The NID requires a tool to open, however it is possible to back the enclosure screw off, to the point that it will open. Its a long screw that secures the case of the NID. I'm not advocating opening the NID.
This will have to wait as my passwords that I have written down from day 1 do not work and I cannot login to the router. Will have to see if it can be remotely reset.
As for the grey enclosure on the outside appears to be no splitter or copper ground
@TECHHEAD as I've said to many others, there's no such thing as a stupid question when it comes to these modems 🙂
I believe that you're using an XB6, XB7 or XB8 modem. In that case, as far as I know, those modems maintain 10.0.0.1 as the LAN address, whether the modem is in Gateway mode or Bridge mode. You should be able to access 10.0.0.1 thru your router.
If you don't remember the password, its usually your wifi password that was set up when the modem was first installed. You might have changed the wifi password since then and I don't know if the modem password follows the wifi password automatically with the XBx modems. I wouldn't think that would happen, but, anything's possible.
If you can't remember the modem password, you can always call tech support to have the modem password set to a temporary password. That would allow you to log into the modem and reset the password to one of your choosing.
Fwiw, that ground block in the NID should have a copper ground wire running from the ground point on the ground block, to the house electrical meter box. At the meter box, Rogers uses a clamp to attach the ground wire to the meter box. That's a minimal effort installation and I often wonder if its really effective. The ground on the cable ground block should help with noise issues introduced by nearby RF transmissions and leakage into the external cable.
I'd recommend one of two ways to ground that ground block. If the house electrical meter box is nearby, that's probably the easiest method of providing a ground point. If you see a Rogers tech as your walking or driving in your neighbouhood, stop and ask him or her for a ground clamp for the meter box and an appropriate length of ground wire. The techs should have some on hand.
If the meter box isn't nearby, ask the tech for a ground block and install that in place of the F-81 connector downstairs that connects the inbound external cable to the cable run the heads up to the modem. Run a copper ground cable from the ground point on the ground block to a nearby house ground point. That could be the electrical panel ground cable, which probably attaches to the incoming copper water line from the street, or you could attach the ground cable to a copper pipe, assuming that you have copper piping that connects all the way to the incoming water line from the street. Do not open the electrical panel. You might see the panel's ground cable running out the bottom of the panel or you might see the other end of that ground cable attached to the incoming water line. If its a simple matter of clamping the cable ground line to that main electrical ground, that would work. If not, clamp the cable ground to a nearby copper water pipe. A hose clamp such as the following would do the job:
That cable ground should do two things, protect the modem and connected systems from nearby lightning strikes and hopefully, shunt any external Electromagnetic Interference to ground, resulting in a reduced error component in the codeword table. Keeping any external noise out of the cable system should result in less codeword errors and need to correct those errors.
@TECHHEAD your signal levels look pretty good. I wouldn't expect you to have any issues based on those signal levels. The question is, do those signal levels degrade over time, as in hours or a few days? Keep track of them over the next week to see what happens.
If and when you have time, can I ask a favour. Can you send a message to @CommunityHelps and ask Tony or Moin to have a look at the OFDM MIBS for the OFDM downstream channel that starts at 920 Mhz. If Tony or Moin can send you a screen capture of the 920 Mhz OFDM MIBS, that would be ideal. The question of the day is "what's the highest frequency band within that OFDM channel". The OFDM MIBS is a breakdown of the OFDM channel into a dozen or so smaller frequency bands. I'm interested in knowing if Rogers has actually started to use the DOCSIS frequency extensions above 1002 Mhz, and your 920 Mhz OFDM channel might show whether or not that's happening.
Follow this link to the @CommunityHelps page when you're logged into the forum. On the right will be a link to Send a Message. Follow that link to the composition page. The address will fill in automatically. Fill in the subject line and details. Include your account number and if you can grab it from the modem, the modem's MAC address. Ask Tony or Moin to look at the 920 Mhz OFDM MIBS and ask for a screen shot of the MIBS display. Hit Send when your ready to send the message to the moderators.
When you're logged into the forum, look for a number overlaying the envelope symbol at the upper right which will indicate a message waiting for you in your message inbox. Follow that envelope link to your message inbox to see the response.
I'm interested in seeing that MIBS display. More importantly, I'm interested in knowing what the highest frequency band happens to be for that OFDM channel.
Thanks very much in advance 🙂
-
4851 views
-
7 Likes
-
-
