1 ACCEPTED SOLUTION
Accepted Solutions
@phucnb1 your signal levels are noticeably better with that temporary repair. When the tech arrives, ask him or her to install new connectors on that repaired section and a new F-81 connector. I'm assuming that is the location where the incoming cable connects to the internal cable that runs up to the wallplate, which in turn connects to the modem.
If I'm correct, the ideal situation would be to replace that repaired inbound cable with a new section of RG-6 cable.
Typically the cable path inbound to a house is as follows:
1. Inbound cable from the local tap, either on a utility pole, or located in a green pedestal near your home runs into an external grey coloured enclosure. That enclosure is called a Network Interface Device, for some reason.
2. Within that NID, there is typically a cable ground block. The inbound cable from the local tap connects to the ground block as does the next cable which runs from the other side of the ground block to the basement location where that inbound cable connects to the cable run that heads upstairs to the modem. There is a ground point on that ground block to which the techs connect a copper ground cable. The other side of that ground cable usually connects to a clamp, which is clamped to the external house electrical box. Usually the electrical box that contains the electrical meter and the NID are co-located.
3. In the basement, that inbound cable from the ground block connects to an F-81 connector which then connects to the cable run that heads upstairs towards the modem.
4. At the wallplate upstairs, there is usually a single cable that connects to the wallplate and the modem. If you need a longer cable to replace the existing two cable configuration, ask the tech to cut an RG-6 cable for you and install connectors on it. At the same time, replace the F-81 connector in the wallplate. I'm assuming that the tech will have F-81 connectors with him or her.
Each one of those cable runs is one individual cable. If you have a cable section that is comprised of two or more sections, they should be replaced by one single cable run.
So, what you should have is:
1. Local tap to external NID: one cable run
2. NID to basement connector location: one cable run
3. Basement connector location to the upstairs wallplate: one cable run
4. Wallplate to modem: one cable run
Each cable run is a single piece section of RG-6 cable.
Ask the tech to:
1. Replace the external cable ground block and install new connectors on all of the outside cables. If you have underground cabling, that will also include the cable end that connects to the local tap. Since that is on the ground, the tech won't have any problems reaching it. Climbing a utility pole is another matter.
2. Ask the tech about that cable section with the temporary repair to it. My personal opinion is that it should be replaced. You'll have to ask the tech to look at that cable run to determine if it needs replacement.
3. Cut the required length of cable to connect the modem to the wallplate and install connectors on it. Also ask the tech for an F-81 connector to replace the connector that sits in the wallplate. I'd go ahead and pull the wallplate off of the wall prior to his or her arrival. If there's enough cable slack behind the wallplate, I'd ask the tech to replace the connector that is on that cable.
If the tech is willing to do all of that to clean up the installation, that might just bring the upstream signal levels down once again. Their not bad where they are now, but, cleaning up the cable ends and replacing the connectors and cable ground block should improve your signal levels. Hopefully that might just resolve the IPV6 issues as a side benefit.
@phucnb1 ignoring the DHCPv6 log entries at this point, the more pressing problem is the cable problem. Your downstream signal levels and upstream signal levels are both elevated beyond their normal levels, which is an odd combination. The target for the downstream QAM levels is 0 dBmV. Yours are sitting in a range of 3.6 to 6 dBmV, which I don't expect to cause issues on the downstream side. The Signal to Noise ratios for the downstream QAM channels are all ok, including the one value sitting at 36.4 dB.
The upstream QAM levels are a problem. They should all be running in a 36 to 40 dBmV range. The DOCSIS spec calls for a maximum of 51 dBmV for three or four channel upstream ops. Rogers uses a maximum of 52 dBmV for some reason. At that point, I'd expect to see one of the upstream channels shut down in order for the modem to operate within its maximum power output level. I wonder if your suffering from short upstream channel disabling? That might manifest itself as a DHCP6 issue of some type, although I'd expect to see different log entries if that was happening.
Its possible that Rogers has decided to use the upstream power level extensions which have been added to the DOCSIS spec. That allows upstream channel operation up to 57 or 58 dBmV, but, I'm not sure how many channels are allowed to run at that power level. That might be a last ditch single channel power level. If you're losing upstream channels, your downstream and upstream data rates will suffer, so, you'll know that something is amiss.
What I don't understand is why the tech didn't tackle the issue of the high upstream signal levels. No amount of modem swaps will solve that issue. Either the tech didn't bother checking the upstream signal levels, or he ignored them. So, you're going to have to chat with tech support once again, or simply send a message to @CommunityHelps, seeking assistance with the signal levels and potential DHCPv6 issue.
If the DHCPv6 issue is a real IPV6 issue with the Cable Modem Termination System (CMTS), you're going to have a problem convincing Rogers tech support that there's an ongoing DHCPv6 issue with the CMTS. You're going to have to chat with a Level II tech who will understand what you're talking about. First line tech support and the field techs won't be able to help you with this. At the end of the day, if this is a real issue, then it will have to go to the Network Operations Center or to a Network Engineer for resolution.
Fwiw .....
Edit: 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.
@Datalink thank you so much for taking the time to write a useful response for me. I think you are correct about the cable problem.
First when I chatted with support, they mentioned that my signals have problems too that why they sent a tech come to help me.
When the tech came, maybe I confused him by mentioned the DHCP v6 errors so we think it was software's problems but not hardware then he just swapped the modem for me.
This morning I check the location where external cable connect to internal cable and I think that is the root of my problem. The external cable's center core almost fail out of the F-81 connector and they used the old connector removed from the wall before (drywall was in the connector). I plug it back to the connector again (temporary) and I notice that the up/down stream levels are closes to the numbers you mentioned.
IndexLock StatusFrequencySNRPower LevelModulation
Downstream | Channel Bonding Value | ||||||||||||||||||||||||||||||||
23 | 7 | 8 | 9 | 2 | 3 | 4 | 5 | 6 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 1 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 0 | 33 |
Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | |
693000000 | 591000000 | 597000000 | 603000000 | 849000000 | 855000000 | 861000000 | 579000000 | 585000000 | 609000000 | 615000000 | 621000000 | 633000000 | 639000000 | 645000000 | 651000000 | 657000000 | 663000000 | 669000000 | 675000000 | 681000000 | 687000000 | 279000000 | 699000000 | 705000000 | 711000000 | 717000000 | 723000000 | 825000000 | 831000000 | 837000000 | 843000000 | 352800000 | |
40.946209 | 40.366287 | 40.946209 | 40.946209 | 38.983261 | 38.983261 | 38.605377 | 40.366287 | 40.946209 | 40.366287 | 40.366287 | 40.366287 | 38.983261 | 40.946209 | 40.366287 | 40.946209 | 40.366287 | 40.366287 | 40.366287 | 40.946209 | 40.946209 | 40.366287 | 31.915308 | 40.946209 | 40.366287 | 40.366287 | 40.366287 | 38.983261 | 40.366287 | 40.366287 | 40.946209 | 38.605377 | 40.13 dB | |
1.799999 | 1.900002 | 1.799999 | 1.900002 | 1.500000 | 0.400002 | 0.500000 | 2.299999 | 2.099998 | 1.900002 | 2.099998 | 2.099998 | 2.400002 | 3.000000 | 2.799999 | 2.599998 | 2.500000 | 2.200001 | 2.000000 | 1.599998 | 1.599998 | 1.599998 | 2.000000 | 1.700001 | 1.900002 | 1.599998 | 1.900002 | 1.799999 | 3.200001 | 3.299999 | 3.200001 | 2.500000 | 1.599998 dBmV | |
QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | OFDM |
IndexLock StatusFrequencySymbol RatePower LevelModulationChannel Type
Upstream | Channel Bonding Value | ||
1 | 2 | 3 | 4 |
Locked | Locked | Not Locked | Not Locked |
32300000 | 38700000 | 21100000 | 25900000 |
5120 KSym/sec | 5120 KSym/sec | 2560 KSym/sec | 5120 KSym/sec |
44.020599 | 43.020599 | 40.010300 | 43.020599 |
64QAM | 64QAM | 64QAM | 64QAM |
US_TYPE_ATDMA | US_TYPE_ATDMA | US_TYPE_TDMA_ATDMA | US_TYPE_ATDMA |
I have an appointment with a tech this afternoon so he may help me to fix the cable then we will see whether it solve the problem.
My modem is not connect directly to the white cable in the image above but to another cable came in the box with the modem (image below), then that cable connect to the white cable. Is it better to connect the modem directly to the white one?
@phucnb1 your signal levels are noticeably better with that temporary repair. When the tech arrives, ask him or her to install new connectors on that repaired section and a new F-81 connector. I'm assuming that is the location where the incoming cable connects to the internal cable that runs up to the wallplate, which in turn connects to the modem.
If I'm correct, the ideal situation would be to replace that repaired inbound cable with a new section of RG-6 cable.
Typically the cable path inbound to a house is as follows:
1. Inbound cable from the local tap, either on a utility pole, or located in a green pedestal near your home runs into an external grey coloured enclosure. That enclosure is called a Network Interface Device, for some reason.
2. Within that NID, there is typically a cable ground block. The inbound cable from the local tap connects to the ground block as does the next cable which runs from the other side of the ground block to the basement location where that inbound cable connects to the cable run that heads upstairs to the modem. There is a ground point on that ground block to which the techs connect a copper ground cable. The other side of that ground cable usually connects to a clamp, which is clamped to the external house electrical box. Usually the electrical box that contains the electrical meter and the NID are co-located.
3. In the basement, that inbound cable from the ground block connects to an F-81 connector which then connects to the cable run that heads upstairs towards the modem.
4. At the wallplate upstairs, there is usually a single cable that connects to the wallplate and the modem. If you need a longer cable to replace the existing two cable configuration, ask the tech to cut an RG-6 cable for you and install connectors on it. At the same time, replace the F-81 connector in the wallplate. I'm assuming that the tech will have F-81 connectors with him or her.
Each one of those cable runs is one individual cable. If you have a cable section that is comprised of two or more sections, they should be replaced by one single cable run.
So, what you should have is:
1. Local tap to external NID: one cable run
2. NID to basement connector location: one cable run
3. Basement connector location to the upstairs wallplate: one cable run
4. Wallplate to modem: one cable run
Each cable run is a single piece section of RG-6 cable.
Ask the tech to:
1. Replace the external cable ground block and install new connectors on all of the outside cables. If you have underground cabling, that will also include the cable end that connects to the local tap. Since that is on the ground, the tech won't have any problems reaching it. Climbing a utility pole is another matter.
2. Ask the tech about that cable section with the temporary repair to it. My personal opinion is that it should be replaced. You'll have to ask the tech to look at that cable run to determine if it needs replacement.
3. Cut the required length of cable to connect the modem to the wallplate and install connectors on it. Also ask the tech for an F-81 connector to replace the connector that sits in the wallplate. I'd go ahead and pull the wallplate off of the wall prior to his or her arrival. If there's enough cable slack behind the wallplate, I'd ask the tech to replace the connector that is on that cable.
If the tech is willing to do all of that to clean up the installation, that might just bring the upstream signal levels down once again. Their not bad where they are now, but, cleaning up the cable ends and replacing the connectors and cable ground block should improve your signal levels. Hopefully that might just resolve the IPV6 issues as a side benefit.
@Vocalicacorn187 it looks like @RogersMoin has moved your post to this thread, based on the similar problems that you outlined. Please have a read thru this thread, from top to bottom. Hopefully you will see the reasons for the following signal level request and inspection:
Part 1.
Please log into your modem and have a look for the data tables that are shown above. They include the downstream table, upstream table and the codeword table. To copy those tables, one at a time, place your curser just in front of the first character in the top left hand corner of the table. Hold the shift key down and scroll down and to the right, to just after the last character in the bottom right hand corner of the table. You can use your mouse to scroll, or the keyboard arrow keys to scroll down and to the right. Release the shift key and use Ctrl c to copy the highlighted or selected data. In a new post, use Ctrl v to paste that data into a post. When the data pastes in, a horizontal scroll bar will be created automatically to allow readers of the post to scroll thru the data to the right.
Please repeat the procedure for all of the tables and paste the copied data into a post.
The normal signal level range for the downstream QAM channels (1 to 32) is 0 dBmV with a Signal to Noise Ratio of 36 to 40 dBmV. The normal signal level output for the upstream QAM channels is 36 to 40 dBmV. There isn't enough data presented within the user interface to judge to health of the downstream Orthogonal Frequency Division Multiplex (OFDM) channels or the upstream Orthogonal Frequency Division Multiple Access (OFDMA) channels. That requires inspection by the moderators or Level II Tech Support. Level I techs don't have access to the OFDM and OFDMA channel internal frequency band data. They have a single amalgamated data line that doesn't show the detail that the moderators or Level II techs can access.
Part 2:
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 house RG-6 cables should be disconnected and moved out of the way. Any in place amplifier should be removed, and any splitter, for now, should also be removed (see below for further explanation).
Any time a cable signal runs thru a splitter, there is a signal drop, from the input port to the output port, so, the object of the exercise at this point is to remove any splitters from the cable system that can cause a signal drop on the downstream path and signal increase on the upstream side. If there is an issue with the external cable that runs to the home which also causes a signal drop along that cable, that signal drop will combine with the splitter signal drop to cause large signal drops leading to the modem. This results in internet outages that can last a few seconds to a few minutes, That will usually depend on the condition of the external cable and its connectors. Rebooting/restarting the modem can temporarily resolve the problem, but, that doesn't resolve the underlying external cable problem. That requires an onsite tech to determine and repair.
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 not be any splitters anywhere along the path, from the inbound cable connection point, point that the cable disappears into the floor or wall. And where the modem is located, there should not be any splitters in the cable path from the wallplate to the modem.
Now, having said that, sometimes, during an installation by a tech, if the inbound signal levels are too high, the tech will install a splitter to drop the signal levels to an appropriate level. The unused ports of the splitter should have been covered with 75 ohm terminators which looks like this:
https://www.homedepot.ca/product/ideal-f-twist-on-terminator/1001046721
The problem with this approach is that the splitter will drop the signal levels in both directions, downstream and upstream. The Cable Modem Termination System (CMTS), which controls the modems and provides the modem's data services will react to the drop in the upstream signal levels by commanding the modem to increase its upstream power level output to meet the signal level requirements at the CMTS. Sometimes the required power output levels are at, or above the point of failure, where the modem cannot provide the required power to run three or four upstream channels at a power level over 52 dBmV as commanded by the CMTS. At that point the modem will shut down upstream channels one by one to remain within its maximum allowable power output. If you were there you would probably know it, as the downstream data rates will drop when there is a loss of one or more upstream channels.
The real solution in cases where the downstream signal levels are too high is a Forward Path Attenuator such as the following:
https://www.multicominc.com/product/multicom-mul-fpa85-forward-path-attenuator/
That attenuator drops the downstream signal levels and leaves the upstream signal levels alone, without any attenuation. That should allow the upstream signal levels to run within in their normal range depending on the condition of the external cable.
For now, lets concentrate on the signal levels and inspection for any amplifiers or splitters within the house cable system.
Please let me know what you find.
I will have to look again tomorrow at the connection between the external and internal to see what the exact part is. There are no splitters. I have a photo attached below though.
These results are right after the internet had gone out and come back.
IndexLock StatusFrequencySNRPower LevelModulation
Downstream | Channel Bonding Value | ||||||||||||||||||||||||||||||||
19 | 7 | 8 | 9 | 2 | 3 | 4 | 5 | 6 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 1 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 0 | 33 |
Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | Locked | |
669000000 | 591000000 | 597000000 | 603000000 | 849000000 | 855000000 | 861000000 | 579000000 | 585000000 | 609000000 | 615000000 | 621000000 | 633000000 | 639000000 | 645000000 | 651000000 | 657000000 | 663000000 | 279000000 | 675000000 | 681000000 | 687000000 | 693000000 | 699000000 | 705000000 | 711000000 | 717000000 | 723000000 | 825000000 | 831000000 | 837000000 | 843000000 | 352800000 | |
38.605377 | 38.605377 | 38.605377 | 38.605377 | 40.946209 | 40.366287 | 40.366287 | 38.983261 | 38.983261 | 38.605377 | 38.605377 | 38.983261 | 38.605377 | 38.605377 | 38.983261 | 38.983261 | 38.983261 | 38.983261 | 38.605377 | 38.605377 | 38.983261 | 38.983261 | 38.983261 | 38.983261 | 38.983261 | 38.983261 | 38.983261 | 38.983261 | 40.366287 | 40.366287 | 40.366287 | 40.366287 | 40.74 dB | |
-5.900002 | -5.500000 | -5.400002 | -5.400002 | -2.000000 | -2.000000 | -1.700001 | -5.299999 | -5.400002 | -5.500000 | -5.799999 | -6.200001 | -5.900002 | -5.700001 | -5.700001 | -5.900002 | -5.700001 | -6.000000 | -5.900002 | -5.299999 | -4.900002 | -4.700001 | -5.099998 | -5.200001 | -5.400002 | -4.900002 | -4.799999 | -4.700001 | -2.599998 | -2.799999 | -2.700001 | -2.500000 | -4.799999 dBmV | |
QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | QAM256 | OFDM |
IndexLock StatusFrequencySymbol RatePower LevelModulationChannel Type
Upstream | Channel Bonding Value | ||
1 | 2 | 3 | 4 |
Locked | Locked | Locked | Locked |
38700000 | 21100000 | 32300000 | 25900000 |
5120 KSym/sec | 2560 KSym/sec | 5120 KSym/sec | 5120 KSym/sec |
49.020599 | 47.260300 | 47.270599 | 47.520599 |
64QAM | 64QAM | 64QAM | 64QAM |
US_TYPE_ATDMA | US_TYPE_TDMA_ATDMA | US_TYPE_ATDMA | US_TYPE_ATDMA |
| CM Error Codewords | |||||||||||||||||||||||||||||||||
Index | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 |
Unerrored Codewords | 18718 | 18602 | 18326 | 18051 | 17932 | 17770 | 17575 | 17424 | 17132 | 16999 | 16870 | 16663 | 16551 | 16420 | 16235 | 16118 | 15990 | 15857 | 15589 | 15453 | 15332 | 15219 | 14998 | 14875 | 14762 | 14573 | 14323 | 14194 | 14063 | 13943 | 11582 | 11434 | 48 |
Correctable Codewords | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Uncorrectable Codewords | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
@Vocalicacorn187 in that picture there are a couple of components. The first is a cable ground block. That has the green copper ground block that runs off to a ground point on your house electrical system. Then there is a filter or attenuator. I can't tell from the picture. At this point I'd remove it and then reboot/restart the modem to see what change there is in the downstream and upstream signal levels. If you run into problems with it removed, you can always reinstall it. If you can post the ID of the component, that would help.
Your signal levels are all low. As that's a snapshot taken right after the modem restarted, that's the best that they can get to at this point. Considering that they will degrade from there isn't a good sign. Can you log into the modem later in the day, hopefully before it or you reboot/restart the modem and post the signal levels again. Where those signal levels are sitting, the downstream is at the lowest point that I'd like to see, and I wouldn't necessarily want to see the upstream signal levels increase at all.
When you switched from Start, was the modem a self install, or did a Rogers tech install the modem?
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