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ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

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Frequent Visitor

ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Greetings:

 

If you are using an ARRIS SB8200 moden, be advised that there is a "Known Issue" and ARTICLE in the COMCAST "System Notifications" (aka: Daily Updates).  If your modem cannot connect (but is still getting signal), it is NOT your modem; it is COMCAST / XFINITY Programming.

 

After three (3) days of MISERY calling from the USA to Technical Support though the Philippines and India with the promise of being "fixed within 3-4 hours, and the numerous Technicians who had no clue what the issue was, the "Known Issue" article and a "ticket" was created with no expected time of resolution.  👍

 

I contacted Arris and here is the cut-and-paste reply from them:

 

"ARRIS Customer Care (saascustomer.care@arris.com):

 

We apologize for the inconvenience you are experiencing being unable to receive internet service through your modem. We are glad to inform you that per our previous troubleshooting, we were able to identify that issues do not relate to the cable modem operation, the device itself shows a stable connection with your ISP. However, the results we got indicate that modem is having trouble to transmit service due to a misconfiguration on the internet provider end. As far as we know, Xfinity is currently working on those outages and it might take some hours for the service to be reestablished, we recommend you to stay tuned for updates from them.
 
If you need immediate assistance or information on ARRIS products, please contact ARRIS Technical Support Center at 1-877-466-8646. We are open 7 days a week 7am - 12am CST.  For information on ARRIS products, we invite you to visit our website at: http://www.arris.com"
 
Good Luck!
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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Apparently I've been impacted by this problem.    Do you have a link to the "Known Issue" article that you could share here?    I ask b/c during my three calls w/ Comcast not a single tech mentioned this as a known issue; apparently they either did not get the memo or failed to read the memo.    I ended up getting the details about the problem from Arris.

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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

I'd like to suggest you post your experience here: https://support.xfinity.com/svp-contact-form

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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

I did a little more digging into this problem and here's what I've found.   In my circumstances it appears that the upsteam power levels have dropped below the acceptable range for the SB8200.   The specs for the SB8200 can be found here.   Look for the power for upstream channels described near the bottom.   The SB8200 has a minimum requirement of 45 dBmV regardless of the number of channels and the maximum is dependent on the number of channels used.

 

I happen to have an old SB6121 which I am currently using.   The specs for the SB6121 are here.   Again, looking at the upstream power requirements near the bottom, I see the minimum power is 45dBmV and the maximum varies according to the number of channels used.     My readings are reporting 41dBmV on four channels.

 

I spoke with Arris support and asked if it is true that even though the modulation is different between the SB6121 and the SB8200, is it safe to assume that the power levels are not and therefore, if I see 41dBmV on the SB6121 I'll see 41dBmV on the SB8200.   The tech said 'yep'.   Therefore, my connection is out of spec for the SB8200 and likely explains my problem.    I note that according to the SB6121 sheet, it is also out of spec there as well but perhaps the SB6121 is more tolerant of low power conditions than the SB8200 is.    Regardless, the fix is to get Comcast to boost the power.

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Diamond Problem Solver

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

That’s incorrect, it doesn’t matter what the specs Arris states. It’s the range that Comcast uses that matters (between 25-51, 45 is nice middle ground).

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Expert

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE


@cxrider wrote:

 

I spoke with Arris support and asked if it is true that even though the modulation is different between the SB6121 and the SB8200, is it safe to assume that the power levels are not and therefore, if I see 41dBmV on the SB6121 I'll see 41dBmV on the SB8200.   The tech said 'yep'.   Therefore, my connection is out of spec for the SB8200 and likely explains my problem.    I note that according to the SB6121 sheet, it is also out of spec there as well but perhaps the SB6121 is more tolerant of low power conditions than the SB8200 is.    Regardless, the fix is to get Comcast to boost the power.


That's not how it works. They can't just "boost the power". The upstream power is controlled automatically by the CMTS (Cable Modem Termination System). The system varies the upstream power to a level to which it can hear the modem with no difficulty.



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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Okay, that's fine.   I don't know how it works and I'm not intimate with the equipment, sadly, this is not my area of experise.   However, I can read specs provided by the manufacturer and that are publicly available, and I can read the values that my modem is reporting.    Based on that information power is out of spec for both of my modems.   I'm about to research whether or not they are out of spec for Comcast modems just to bolster my case;   I suspect that they are given that we work in a world of protocols and standards, but perhaps it is the case that the SB modems are clipping the lower end of power and the Comcast modems work fine with low power; clearly my SB6121 handles it despite being out of spec.

 

Regardless of whether or not it is the case that the power is in spec for Comcast modems, Comcast says it supports the SB8200 modem, the manufacturer says that the minimum power for the upstream channel is 45 dBmV, and my modem is reporting 40-41 dBmV; either the CMTS is not supplying the necessary power or there is a loss in the line, neither of which is my problem to fix.  🙂

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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Huh?   You need to explain yourself and hopefully educate me because it sounds like you're saying this:

I have a tire.   The tire manufacturer says that the tire must be used with a minimum tire pressure of 45 psi and no more than 51 psi otherwise the tire may fail.  My mechanic fills the tire to 40 psi because they want to.   The tire fails and somehow it's the fault of the tire manufacturer?  

If you have info like a link to the signal spec which says that the power must be supported at a value less than 45 dBmV, then I'd like to see it; that would be an indication that Arris has clipped the lower end of the spec; it 's doesn't change the fact that their posted spec says a minimum of 45 dBmV, and it doesn't change the fact that Comcast says they support SB8200 modems, but at least it allows us poor owners of their equipment to understand why things aren't working and it allows us to make better choices about the equipment we purchase. 

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Expert

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE


@cxrider wrote:

Okay, that's fine.   I don't know how it works and I'm not intimate with the equipment, sadly, this is not my area of experise.   However, I can read specs provided by the manufacturer and that are publicly available, and I can read the values that my modem is reporting.    Based on that information power is out of spec for both of my modems.   I'm about to research whether or not they are out of spec for Comcast modems just to bolster my case;   I suspect that they are given that we work in a world of protocols and standards, but perhaps it is the case that the SB modems are clipping the lower end of power and the Comcast modems work fine with low power; clearly my SB6121 handles it despite being out of spec.

 

Regardless of whether or not it is the case that the power is in spec for Comcast modems, Comcast says it supports the SB8200 modem, the manufacturer says that the minimum power for the upstream channel is 45 dBmV, and my modem is reporting 40-41 dBmV; either the CMTS is not supplying the necessary power or there is a loss in the line, neither of which is my problem to fix.  🙂


These are the Comcast system / cable plant spec from the troubleshooting tips sticky topic at the top of this board. Again, they are the only ones that really matter;

 

Downstream Power Levels: -8dBmV to  +10dBmV

Downstream Signal to Noise Ratio (SNR):  >35dB 

Upstream Power Level:  +25dBmV to +54dBmV

Upstream Signal to Noise Ratio (uSNR): >31dB  

Upstream Receive Power: -2dBmV to +2dBmV

 



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Expert

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE


@cxrider wrote:

Huh?   You need to explain yourself and hopefully educate me because it sounds like you're saying this:

I have a tire.   The tire manufacturer says that the tire must be used with a minimum tire pressure of 45 psi and no more than 51 psi otherwise the tire may fail.  My mechanic fills the tire to 40 psi because they want to.   The tire fails and somehow it's the fault of the tire manufacturer?  

If you have info like a link to the signal spec which says that the power must be supported at a value less than 45 dBmV, then I'd like to see it; that would be an indication that Arris has clipped the lower end of the spec; it 's doesn't change the fact that their posted spec says a minimum of 45 dBmV, and it doesn't change the fact that Comcast says they support SB8200 modems, but at least it allows us poor owners of their equipment to understand why things aren't working and it allows us to make better choices about the equipment we purchase. 


Nope. Not at all. Comparing that example with the way that DOCSIS / RF modem's signals work is like compairing apples and oranges. It is beyond the scope of these help forums to educate / train anyone, sorry. Suggest that you do research into they way that DOCSIS / RF system works.



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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Great!   Thanks for those numbers.   I joined the forum yesterday and had not noticed the sticky post of troubleshooting my connection; not that it would have mattered because my SB8200 modem is not responding on its IP address so I would not have be able to determine there's a signal problem.

 

Since my downstream channels on the SB6121 are reporting 33 to 34 dBmV, it's out of spec even by Comcast standards.    Going back through my logs I discovered that my downstream power for my SB8200 dropped below 35 dBmV around 29 Nov and have been below Comcast acceptable levels since that time;  I guess I've been lucky to this point it's been working at all.  

After contacting ComcastCares on twitter, I was able to learn that my downstream power is 33.4 dBmV; I'm guessing this is measured at the CMTS, but it's out of spec and I now have an appointment for a line check; the third one in six months and the first two resulted in line 'fixes'.   I also asked the ComcastCares rep whether or not they can read values from my modem.  The answer I got was 'no', that only I can see them.    This doesn't jive with what's reported in the troubleshooting guide; that's fine, I know how to read my values but it seems really problematic to me that:

 

  1 - Comcast help line doesn't seem able to actually read the power levels for the Comcast side of the connection given that there have been many, many calls where the answer was 'there's no line problem, it must be your modem'.

  2 - Comcast help line doesn't seem know that just because power values on one side of the connection are okay that doesn't mean they are okay on the other; or they don't care what they are on the other as long as it's good on the CMTS side, I don't know which it is.

 

Regardless, I now know what SNR/power levels are acceptable, I'll be monitoring them, and I'll generate a line check call each time they drop below the approved levels.  

 

 

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Gold Problem Solver

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE


@cxrider wrote: ... downstream channels on the SB6121 are reporting 33 to 34 dBmV ... downstream power for my SB8200 dropped below 35 dBmV ... my downstream power is 33.4 dBmV ...

Those numbers can't be correct for downstream power levels. Perhaps they are upstream levels, or SNR? Note that SNR should be reported in "dB", not "dBmV".

 


... downstream power is 33.4 dBmV; I'm guessing this is measured at the CMTS ...

No, downstream power is the signal strenth received by the modem, so that's where it's measured.

 


... I also asked the ComcastCares rep whether or not they can read values from my modem.  The answer I got was 'no', that only I can see them. ...

That's incorrect. Comcast can see all the modem stats you can, as well as a few more you can't see because they are measured at the CMTS and not communicated back to the modem. Sadly, asking Comcast phone and chat reps for technical info is fraught with peril. Some have a basic understanding of modem signals and can do it, but many do not and cannot.

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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

You're correct, I misspoke when I said SNR had units of dBmV; apologies.    The values are still consistent and out of spec.

 

Here's the latest values my modem is reporting:

 

 

 

SB6121-19Jan2020.png
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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

And for what it's worth, here are the values I logged back in Nov.    Some time around Sep 2019 I started hourly logs of downstream values.    I did this because I've had months of problems.  Time format is YYYYDoYHH where:

  -YYYY is four digit year

  - DoY is a three digit day of year; Jan 01 is 001

  - HH is a two digit hour; range is 00 - 23

 

There was a an outage of less than four hours after which the SNR levels had dropped:

 

 

30Nov2019UTC00.png
30Nov2019UTC01-03.png
30Nov2019UTC04.png
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Expert

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

On your latest values, the SNR's are on the low side. Perhaps there is noise ingress leaking into the line(s) somewhere.



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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Yep, and unless I experienced a double failure (modem died + line problem) I'm thinking that the SB8200 can't establish a connection with SNRs in the 33-34 dB range whereas, the SB6121 can and the only problem out there is a line problem.  

 

FWIW, box to modem is a single cable, no splitters, no extenders, just two F connectors and wire.  🙂

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Expert

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.

Good luck with this !



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Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

That's what I want.   I want them to measure signal at the box; I already know the signal is low at the modem so no need to start there.   If the signal is out of spec at my box the problem is between the box and the CMTS; if it's solid at the box it's between the box and my modem and is my problem to fix.    I have a compression tool, compression F connectors, and RG6 cable so I should be able to fix my end in short order.   🙂

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Frequent Visitor

UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

So, after ALLLLLL of this discussion and time everyone has taken to share these amazing and wonderful technical details expressing the same issue: 

 

Can anyone confirm that Comcast / XFINITY stated that they are actually working on the problem?  (and, if so, share equal parts of technical detail)

 

I have called and called but not a single person from Comcast / XFINITY can confirm that it is being immediately resolved....

 

NOTE:  I did get my Comcast / XFINITY bill on time and I bet if I dsay I am having "technical issues" paying my bill they would be acting VERY quickly to.....  DISCONNECT.

 

UGGGG!!!!

 

 

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Frequent Visitor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

I apologize:  there is no "link" to the Comcast / XFINITY issue - it's all lip-service.  I asked for the Article, Notes, the Tech Ticket, etc.  They gave me nothing..... 

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Regular Contributor

Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

I spoke with the tech regarding the problem with the 8200 while he was inspecting my line.    He mentioned that Comcast has made changes to support new packages and his thought was that Comcast may have messed up a setting which affects the 8200 but he couldn't say for certain.   Comcast will be back out today (hopefully) to check the main line.   I'll try to ask the tech  how I go about talking to someone at Comcast that would be able to determine what if anything is being done about the 8200.

 

Here are a few other points that came out of that conversation:

 

  - When a tech 'provisions' your modem that means they push configuration information to your modem so that your modem may operate on the network.      If the phone tech tells you that they *never* push anything to your modem then they do not know what they are talking about; it might be worth asking for a different tech.  

 

  - Techs can read the stats from your modem, if it is up (and this makes sense).    If they tell you that there are no problems with the line and you suspect there is (and honestly any more, I'm *always* going to suspect there is a problem with the line as the first order of business), have them tell you the SNR/power readings from your modem and the CMTS.   Ask for error counts (correctable and uncorrectable).    According to the tech I talked with Comcast can access up to two weeks of line info if it exists; my tech from last night said he pulled two weeks of data about my line before he came out to inspect it, and sure enough, low signal.  He also said there may be less than two weeks of data if the modem was recently added.  If the phone tech continues to insist they can not read your modem, ask for a different tech because they don't know what they are talking about (my words, he never suggested not using the phone techs).

 

  - Provisioning does not necessarily mean a firmware update.   If your modem needs a firmware update, and if Comcast enables it, your modem will download new firmware, most likely from the manufacturer web site, and reboot.  

 

In the mean time have you posted your experience to Tom?    If not please do.   Comcast claims they will respond within a business day; it's another avenue to pursue in getting this resolved.  I can't work on modem issue with Comcast until my line is fixed as I can not prove that the only reason my 8200 isn't working is due to a Comcast change; as much as I believe it to be the case.   Regardless, *if* I actually get a response I intend to use it as a means to figure out how to get answers to the 8200 problem.    Once I know more I'll post it here.

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Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Thank you for the information you have provided.

In the interim, I have gone to an older modem which is working just fine. I have sent a direct message to Tom using the available link and it has only been a few hours. So far, no response but they did say to wait about a day.

I have since followed up with Comcast and Aaris and they have both told me that Comcast is working on it. To be very candid, I do not have faith it will be resolved timely which is very disappointing considering that the unit is posted as an acceptable device and in further consideration that they are charging me for speeds that I cannot access at this time.

From what I have reported and from what you have reported, we are both correct and on the right track. The only thing we can do is hope and pray that Comcast actually is doing something about it and does it soon. I will continually check to see if my modem works and if so, will post accordingly. I have been advised that Comcast will not send me a message, email or any other style of communication once it is corrected, if ever.
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Expert

Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE


@cxrider wrote:

 

 - When a tech 'provisions' your modem that means they push configuration information to your modem so that your modem may operate on the network.      If the phone tech tells you that they *never* push anything to your modem then they do not know what they are talking about; it might be worth asking for a different tech.  

 

  - Techs can read the stats from your modem, if it is up (and this makes sense).    If they tell you that there are no problems with the line and you suspect there is (and honestly any more, I'm *always* going to suspect there is a problem with the line as the first order of business), have them tell you the SNR/power readings from your modem and the CMTS.   Ask for error counts (correctable and uncorrectable).    According to the tech I talked with Comcast can access up to two weeks of line info if it exists; my tech from last night said he pulled two weeks of data about my line before he came out to inspect it, and sure enough, low signal.  He also said there may be less than two weeks of data if the modem was recently added.  If the phone tech continues to insist they can not read your modem, ask for a different tech because they don't know what they are talking about (my words, he never suggested not using the phone techs).

 

FWIW, the phone people are NOT cable "techs". They are merely CSR's with limited amounts of training. Just sayin'.

 

  - Provisioning does not necessarily mean a firmware update.   If your modem needs a firmware update, and if Comcast enables it, your modem will download new firmware, most likely from the manufacturer web site, and reboot.  

 

The firmware loads come from Comcast's own in house servers via TFTP.


 



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New Poster

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

I’m not sure where to jump in on this. About a week ago, I could no longer get internet connectivity through my SB8200 modem. I could not connect to the modem, using the default 192.168.100.1 IP address. My Asus router reported a DHCP problem with the ISP. Comcast said it was a problem with my modem. They made an appointment for a technician to come out the next evening. No one showed! When I inquired, they said the appointment had been cancelled! In desperation, I hooked up an old SB6121 modem. It worked fine, and my router reported a good connection. I purchased a new Netgear CM1000 DOCSis 3.1 modem. It has the same connection problems as the SB8200, so the problem has to be with Comcast

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Frequent Visitor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Greetings and welcome to the wonderful world of Comcast!

Your equipment is working fine and there is no need to buy another unit. You can go ahead and return the replacement unit. The problem is entirely with Comcast. On or about January 5th or 10th or 15th, 2020, Comcast updated their systems. In doing so, they blew out equipment running on settings such as your AARIS.

I have submitted a direct message to Tom, the CEO of Comcast, and obviously a third-party responded. Other than lip service, I have no more information. My only suggestion is that you contact Comcast and ask for it to be escalated as many of us already have so that the problem can get large enough for them to finally do something.

Again, the equipment is correct and it is an approved device with Comcast. You can search the available and approve devices on their website.

In summary: it’s not your equipment. It’s Comcast. Good luck.
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New Poster

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

I have just tried my new Netgear modem, and it is now working. I will go back to the Arris modem soon, as I like it better. I assume the problem with it is fixed, also. Thanks!

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New Poster

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

I had an outage on 1/5/20. And I have an Arris SB8200 modem. At first I called Comcast and I got someone with an accent that did state they had multiple complaints from people with the SB8200 modems. They stated to reset, which I already did several times with no luck so I contacted service to come out to my home.

 

A service tech came out, to which he connected his green lighted (word redacted) box (just lights, no real measurement of readings) and said everything was o.k. on their end. He disconnected my modem and connected one of his which worked and he condemned my modem stating that it was bad. I called Arris because this was a brand new modem that I just purchased a couple months ago and they stated that Comcast was in fact having a problem with the SB8200 modems.

 

Called back to Comcast again but this time I got someone who spoke english with no accent. He said he checked my connection and it was going in and out and can have another tech out tomorrow. That evening in my frustration I unplugged my modem for about an hour and then reconnected and everything has been up and running fine (must be some kinda comcast magic) I called Comcast and cancelled the scheduled service call for the next day and everything has been just peachy since.

Side note: The first tech did remove my PPC EVO 1-5-U/U splitter and installed a couple little splitters but it made no difference after he left because I still did not have service

 

I do not kow why Comcast never admitted that they did something to my modem. I did suspect a bad update but they would not say they did that when I asked the second time I called.

 

I would like to thank those that posted the links to the specs of my modem, and I will check those power readings tomorrow to see if Comcast is within spec of this modem, if not I will request a line check with a tech that actually uses a real meter

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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Gotta love it!   I assume the Netgear CM1000 is a "supported" modem?

 

Please be sure to post your experience here     'Someone from Tom's office will get back to you in one business day'.   You'll even get an official looking number to make you think someone is actually tracking it.   I posted Friday night; it's now Wednesday and I've not had a response. I'll be interested to hear whether or not you get an actual reply.  

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Frequent Visitor

Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

I just bought a new SB8200 and installed it to replace my SB6121 last evening.  I cannot get to 192.168.100.1 IP address with web browser (tried 4 of them) and yet I could with the older modem immediately prior to install of SB8200.  I self provisioned using xfinity.com/activate.  Are you saying I still need to call Comcast to get this fixed?  Thanks.

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Regular Contributor

Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Yes and good luck because Comcast has not recognized, and will not acknowledge, that there is an issue. 

 

Have fun!   I'd like to hear how it goes for you.   

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Frequent Visitor

Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

...you can try as we all have BUT nothing is going to change until COMCAST fixes the issue on their side.  For the right information to share with the COMCAST Agent, use the above intel above; it speeds-up the process.

 

FYI:  The Arris SB8200 works GREAT (...only if your internet provider did first).

 

Good luck!

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Regular Contributor

Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Hey, just curious.   You said that you have an old SB6121 and tried upgrading to the SB8200 (FYI, I did the same thing 10 months ago b/c Comcast said the six months of problems I had were due to my modem; turned out it was a line issue).   I had to fall back to the 6121 after the "change" last week.    I am assuming that you've dropped the 6121 back in while you try to debug this problem.   What do you see on your signal page for the 'Signal to Noise Ratio' for the Downstream bonding channels and what are you seeing for the 'Power Level' on the upstream Bonding channels?

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Regular Contributor

Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

So.....

 

The main has been repaired and the SNR levels are back to where they were before the outage.    No behaviour change from my SB8200.....sadly, it appears that my modem is dead.     I grabbed a new one from Best Buy and it's working like a champ.

 

The kicker for me was my conversation with the phone rep while trying to get my old SB8200 online after the end of the maintenance; he said he had a SB8200 and he's not having problems.... but his SNR are in the 40s for downstream and he wasn't sure for upstream.   He also said that he can access the modem ethernet interface from his LAN even if his service is out; I could not do that with my old SB8200 post outage and since the SNR levels were back to normal for here I was out of options for the modem not working.

 

YMMV

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Frequent Visitor

Re: UPDATE (?) : ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

FYI - No change here.  My "Comcast Approved" Arris SB8200 remains a decoration.

 

Upon further investigating, the "changes" that have been made (which I beleive they rolled-back to the original settings) are not "active".

 

...I foresee a MAX EXODUS coming from Comcast.

 

Good Luck Everyone!

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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Are you able to see your hardware/software revision on your 8200?     I ask because I think the version is different on the new 8200 vs my old 8200.   I believe this is the case because I wrote a python script to harvest the values for downstream channels.   It ran for months without an error collecting data.   Since starting the new modem it now complains about invalid data in all columns, namely the column headers:  "Channel ID", "Lock Status", "Modulation", "Frequency", "Power", "SNR/MER", "Corrected", and "Uncorrectables".    

 

FWIW, I see this for hardware/software versions:

  Hardware Version: 6

  Software Version: D31CM-PEREGRINE-1.1.1.0-GA-11-NOSH

 

 

Lol... and I *just* looked at the log.... perhaps this is why it is working:

 

1-24-2020, 17:11:22 Error(4) "SW upgrade Failed after download - Incompatible SW file"
1-24-2020, 17:11:22 Notice(6) "SW Download INIT - Via Config file d11_m_sbg8300_performance2_c01.cm"
1-24-2020, 17:11:18 Warning(5) "Dynamic Range Window violation"
1-24-2020, 17:11:18 Warning(5) "RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=14:c0:3e:01:a4:55;CMTS-MAC=00:01:5c:65:24:4d;CM-QOS=1.1;CM-VER=3.1;"
1-24-2020, 17:11:17 Warning(5) "Dynamic Range Window violation"
1-24-2020, 17:11:17 Warning(5) "RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=14:c0:3e:01:a4:55;CMTS-MAC=00:01:5c:65:24:4d;CM-QOS=1.1;CM-VER=3.1;"
1-24-2020, 17:11:17 Warning(5) "Dynamic Range Window violation"

 

Notice the config file name - SBG8300 but I have an SB8200.   Maybe I lucked out b/c the tech fat-fingered the boot file, the upgrade fails, and I'm running the stock boot file.......

 

Here you go... if you have time.

 

  - Factory reset your 8200 - hopefully this gets you back to the stock 8200 boot file

  - Call comcast and have them provision your "new" modem as a SBG8300

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Frequent Visitor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Inasmuch as I would enjoy going through the process to get answers as to why my SB8200 isn't working, it does not change the "COMCAST Effect".

 

For the record:  I have had my SB8200 for approximately 6 / 7 months.

 

Thank you for the intel.

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Regular Contributor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Just curious, is this still and outstanding issue or did you get resolution? 

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New Poster

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

After several days, the problem cleared up. I assumed Comcast had fixed the problem on their end. I then requested an upgrade for my internet speed. The original symptems again appeared. After much testing, I found a computer plugged directly into the Arris modem, worked fine. However nothing would work through my router. Eventuly, I found and changed a setting in my router. I now have much greater speeds. I think what I changed, was the DNS setting.

 

My problem is solved!

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Regular Visitor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Hello,

I have SB8200 on the Comcast Network. Looking at the status info

 Upstream Bonded Channels: 1 2 3

 power levels 50, 51, 50 dbmv.    Meet Specs.

 

Downstream Bonded Channels: 9-40, 159

Power and SNR levels for channels 9-40 - Meet specs.

 

Channel 159 

 

159 Locked Other 690000000 Hz -2.2 dBmV 20.8 dB 709192998 385

 

Modulation labled as "Other'  with huge number of corrected (709192998) and Uncorrectables 385 

 

Does this info for channel 159 look OK to you all? Thanks.

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Expert

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

 

The "Other" channel is the DOCSIS 3.1 / OFDM downstream that is used to transport their Gigabit speed tier and there is a known firmware issue with some makes / models of modems that read this channel incorrectly.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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Regular Visitor

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

Hello EG,

 

I greatly appreciate your comments and recommendations.

 

  1. As you observed, the power values for the Upstream channels are at the upper range. I do have speed fluctuation issues, buffering delays, and momentarily outages (getting “hostname is not resolved” message since the DNS access fails). I have done numerous power cycles and resets (through Comcast App) on the modem but the problem persists. I have yet to do the factory reset on modem.
  2. The setup consists of an SB8200 paired with a Nighthawk X6 R8000 router. Both are about 18 months old. The line consists of the original cable that is extended by about 6 feet using a connector and was snaked through the wall to a RiteAV 1 Gang Wall Plate 2 Port - Cat6 (Shielded) Coax. A short coax cable connects the SB8200 (sitting on a shelf) to the Wall Plate’s Coax port.
  3.  There are no splitters in the line but the signal goes through a connector, Wall Plate coax port,  a short cable to the SB8200. Do you see any issue with this line configuration that may be causing the behavior that I am observing and the high Upstream channels’ powers?
  4.  Regarding the Downstream Channel 159, I presume the firmware that you are referring to is the one on SB8200. I checked the Arris website and there is no updated firmware available for SB8200 listed. Therefore a large number of corrected and uncorrectable bits mentioned on the Status are due to SB8200 firmware issues and can be safely be ignored. Is that correct? I do not have the Comcast Gigabit plan.
  5. Looking at the Modem’s event log, I noticed some events’ timestamp (year, day, time)  refer to the1970 01 01 while the majority was 2020 correct days and times. Is that normal? When I refreshed the event log, the 1970 timestamps disappeared. I am a bit puzzled on the significant of 1970 01 01 timestamped  events
  6. I plan to do the modem factory reset, reconfigure the line to the basics depending on your feedback and then getting Comcast involved if the problem insists. I am sure you are aware that Comcast treats those customers who insist to have their own modems rather than renting the Comcast refurbished inferior ones like the second class citizens. Their first line support always refers the customers to the Modem Manufacturer Support if they see an acceptable signal level at the modem from their end.  

 

Thank you again for your valuable contribution to this forum and the members.

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Expert

Re: ARRIS SB8200 and COMCAST / XFINITY - MISCONFIGURATION ISSUE

It's my pleasure !  😊



I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!