@DigTV99 don't confuse a time out at the 8th hop with a disconnect issue. If you're finding that your service disconnects, the first place to look is the external cable that runs from your home to the local tap. In fact, to test for this correctly the first target in a ping test is the modem, the next target is the Cable Modem Termination System (hop #2). Any ping tests that you're running should be done via ethernet, not wifi.
The data path that you're testing is as follows:
1. PC or laptop to the modem via ethernet
2. modem to the external Network Interface Device (NID), which is the grey box mounted outside of your home. That is a copper cable path, usually RG-6 cabling.
3. NID to local tap, which is located in a nearby pedestal if you have underground cabling or up on a nearby utility pole if you have overhead cabling to your home. The pedestal is probably visible from your front door, if you have underground cabling in your neighbourhood. That is a copper cable path, usually RG-6 cabling.
4. Local tap to neighbourhood node, via hard cable
5. Neighbourhood node to the Cable Modem Termination System via fibre optic cable.
So, first test is to ping the modem to determine if there's an issue with the modem responding. its possible that if the cable feed to the modem goes down, that the ethernet output from the modem might go down as well. That is something that pingplotter would show, or, you could run two consecutive ping tests using a Windows ping command, one aimed at the modem and one aimed at hop #2. Assuming that you find that the modem always responds, no matter what's going on after the modem, then its time to move on to the CMTS as a target.
I'm assuming that you've switched over to one of the Ignite (read Comcast XBx) modem. It really doesn't matter what modem is in place as a disconnect caused by an external cable fault affects any modem that you might be running. The external cable is the Achilles heal of the cable system. It has a limited lifespan and will either degrade slowly, causing disconnects as you're experiencing or it will go the final end and simply fail, which is much easier to diagnose. That cable could last a few years, or it might be serviceable for 15 years or more. Each installation is unique.
Ok, so, assuming that you have a problem with the external cable and/or its connectors, the way to see that is by pinging the CMTS, hop #2 in a trace to anywhere.
Run a trace to anywhere: tracert -4 www.google.com
That runs an IPv4 trace to google. Use the IP address for hop #2 (assuming that the modem is running in Gateway mode) and use that as a target for Pingplotter. Pingplotter automatically places the target ping results in the bottom display area. That hides all of the intermediate hops between the modem and the end target. So, yes, you will see a disconnect from google when the cable that runs to the local tap disconnects, but, that's not a upstream Rogers network fault, its most likely its a local cable fault which you can't see due to Pingplotter's display of the end target. So, restricting your ping test to the CMTS will show when you have disconnects from the network. While problems like this are normally caused by the external cable, there is always the possibility of problems further upstream, including the local tap itself which is an upscaled splitter of sorts, the cable run to the neighbourhood node and the neighbourhood node itself. And there is always the possibility that someone in your neighbourhood has connected something to the cable system which shouldn't be connected, and as a result, the rest of the neighbourhood experiences problem with their cable system. This last one is a problem to determine and localize.
Personal opinion, don't use Pingplotter for long term testing. It generates a considerable amount of traffic on its own. At this point, if you want to, use it to visually confirm that the modem ping results are separate from the CMTS results (beyond the modem). That's what I would expect to happen, but, I've never run into a disconnect situation with the XB7 that we have, so, I can't say with any certainty that the modem will still respond properly when there is an external disconnect. Maybe Comcast designed the modem to stop responding entirely when there is an external disconnect. That possibility has to be entertained at this point.
So, you can use Pingplotter for short term testing if you prefer, but I recommend switching to a Windows ping test for longer term testing.
I have posted a procedure to use Windows Powershell which will run the ping test and capture the results in a text file.
By examining the text file you can quantify the number of disconnects that your experiencing in a day. Running the ping test, aimed at the CMTS will show that the fault is somewhere between the modem and the CMTS, most likely with your external cable.
If you have underground cabling, a tech can easily test the cable by running a Time Domain Reflectometry (TDR) test. He or she will disconnect the cable at both ends and fire a pulse down the cable using the TDR test device. The return pulse will come from the other end of the cable, or the point where there is a disconnect, most likely caused by water in the cable. If the cable length measures the same when tested from both ends then the question is whether or not there is a significant loss of signal power from one end to the other. In cases where the cable measures different lengths when tested from both ends, then the cable is not serviceable and requires replacement.
So, hope this helps. Fwiw, ask your immediate neighbours if they're on Rogers cable and whether or not they are also experiencing any disconnects. If so, that points to the local tap or beyond. That's an important point in troubleshooting as it moves the task from a contract tech to a Senior Tech (real Rogers tech) or possibly to a maintenance crew.
Note that if you reboot the modem and that temporarily resolves the problem, that is a sign that you have an external cable and/or connector issue.
Assuming that you have one of the Ignite modems (Comcast XB6, XB7 or XB8), when that modem was installed, the tech, or you should have disconnected any cable splitters in the cable system and connected the inbound cable to the modem cable using an F-81 connector which looks like this:
https://www.homedepot.ca/product/ideal-3ghz-f-splice-adapter-10-pack-/1000751479
Cable splitters drop the signal levels at the outbound ports, so, with the change to the single XBx modem in the house, any splitters in the cable system should have been removed.
One last item is to post your cable signal stats. Log into your modem and navigate to Gateway > Connection > Rogers Network. At the bottom of the page you'll see three tables, Downstream, Upstream and CM Error Codewords. To copy those tables place your curser in front of the first character in the table title, that is in front of Downstream, Upstream, and CM. Hold down the shift key and scroll down and to the right of the individual table until your curser sits just after the last character in the bottom right hand data cell. Release the shift key and right click ..... Copy. In a new post, right click .... Paste. That should paste in the table, as it appears in the modem's user interface. Do that for all three tables.
Copy the data after the modem has been running for a period of time. During that time period, the signal levels will degrade, to the point where the modem will reboot to re-establish coms with the Cable Modem Termination System. After the reboot, the signal levels will probably appear as they are expected to appear. The reboot brings them back to an operating level, so, seeing those levels after a reboot doesn't prove very much. But, if the external cable / connectors are almost dead, then even a reboot won't salvage the signal levels and that would show up in the signal levels. So, when you copy and post the signal levels, indicate (roughly) how long the modem has been running.
@DigTV99 wrote:
I don't know how to read these stats. Any input would be appreciated.
Your downstream power levels and SNR are all within norms.
On the upstream side, power levels are also okay. One thing of note is that you do not have an upstream (DOCSIS 3.1) OFDMA channel; my guess is that your neighbourhood is still being served by an old analog fibre node. Not catastrophic but is does cap upload speeds in your area to 100 Mbps.
The only question is, what is going on within the OFDM channel, which starts at 350 Mhz, and probably stops around 500 Mhz. That signal to noise ratio is an average of some type, same that is displayed to the Level I techs that you chat with over the phone. There can be a wide range of signal levels within that frequency range that aren't displayed on the table. The only Rogers staff that have access to the OFDM MIBs are the moderators and the Level II techs. That MIB data is a breakdown of the OFDM channel into smaller bands, each which its own signal to noise rations and pass/fail criteria.
Looking at your signal levels, there's nothing to suggest that you would suffer from momentary disconnects, so, its a definite mystery at this point. We're you able to read thru the post with the instructions to run a ping test using Powershell? Running a normal ping test with the Windows ping command will run the test, but, there's no timestamp. You can look thru the results, but, unless you're aware of the start and stop times, you don't have a good idea of when the disconnects occurred. That is why I suggest the Powershell route. You could leave that running for a considerable amount of time, days if you prefer. Only hiccup is looking at the results. Windows notepad chokes on large text files. You can use Notepad++ which is available from:
That opens large files without any problem. I don't remember the ping test result text when a disconnect occurs. Its a timeout of some type. When you see what the text indicates, you can search for the text and the search function within Notepad++ will indicate how many occurrences there are within the file. With that data on hand, you could copy the portions of the result file that indicate when the disconnects occur and send that to the moderators to look at the CMTS traffic to see what is happening on the CMTS end. Running a test for at least 24 hours should give you an idea of the number of disconnect occurrences that you're seeing.
For now send a message to the moderators asking them to look at the OFDM MIBs data for your modem, just to see if anything is beyond limits.
@CommunityHelps is the group address for the moderators here on the Rogers Forum. When you're logged into the forum, follow this link to the @CommunityHelps page. On that page will be a link on the right hand side to Send a Message. Follow that link to the message composition page. The address will fill in automatically. Fill in the subject and details, including your account number and when the message is complete, hit Send Message at the bottom.
When you're logged into the forum, look for a number overlaying the envelope symbol at the upper right hand corner. That will indicate that there's an inbound message for you. Follow that envelope symbol as it serves as a link to the message inbox and outbox. From the response in the inbox you can then message back and forth as required. There will be an authentication procedure that you will have to complete in order to service any change requests for your account.
To send anyone else on the forum a message, including @CommunityHelps, hover your mouse over their user name and a popup will appear with a link to send a Private Message. Follow that Private Message link to the message composition page and as before the message addressee will fill in automatically. Fill in the subject and details and hit Send Message when you're ready to send the message.
Just to note, the change in modems, from the previous generation modems results in a technology change, from a Quadrature Amplitude Modulation (QAM) to an Orthogonal Frequency Division Multiplex format. This is a change from 32 higher signal level QAM type carriers to thousands of lower signal level data Sub-carriers. That is a major change in signal levels and carrier type. So, we've seen many cases where the previous generation modems would run without any issue, but, now, with an OFDM modem in place, the customer experiences ongoing problems.
@DigTV99 wrote:
Index Unerrored Codewords Correctable CodewordsUncorrectable Codewords
CM Error Code words
Sorry, I missed this post with your error stats... and you are getting quite a large number of uncorrectable codeword errors. Ideally, you should have zero (or close to zero) uncorrectable errors. That is packet loss.
You should PM @CommunityHelps and ask them again to check on the health of your connection and that of your immediate neighbours. You should also ask them to check the construction schedule for your area to see if they plan to upgrade your fibre node anytime in the near future.
The frustrating thing is that even if your neighbourhood is plagued with longstanding issues and instability, if your node is due for an upgrade, Rogers likely will not schedule a maintenance team to fix anything until after that upgrade is complete.
@DigTV99 have a look at the junction point where the inbound cable meets the cable run to the modem. There should already be an F-81 connector installed. If you still have a splitter installed, how many ports are on that splitter? If you take out a splitter and install an F-81 connector, the inbound signal levels will rise and the outbound signal levels will fall. The question is, to they rise or fall beyond limits, ergo, the question regarding a possible splitter still in place?
-
6458 views
-
15 Likes
-
-
