CM500V with Comcast - other Comcast landline callers cannot hear me when calling landline phone

[sferrell615]

I am one of a large number of people having a Comcast phone issue (caller cannot hear me) and the issue appears to be Netgear modem related so I would imagine that Netgear would help to resolve this issue.

The issue is 

1) Based on this site the Netgear CM500V modem (internet and phone) just works with Comcast.

https://kb.netgear.com/000036375/What-s-the-latest-firmware-version-of-my-NETGEAR-cable-modem-or-mod...

2) I have a Netgear CM500V modem with Comcast service.

3) The Netgear CM500V modem has worked for me (internet and phone) for almost 2 years.

4) For the last 2 months when another Comcast caller from a landline phone calls my Comcast landline phone that caller cannot hear me.  I do not have issues when a non-Comcast caller calls me, I am able to be heard on most of the outgoing calls (including to other Comcast callers), and the internet continues to work well.  

5) A Comcast technician came to where I live and troubleshot the issue.  He replaced the coax, phone, phone line, and (last) modem.  When he replaced the Netgear CM500V modem with an Arris TG1682G modem the issue was resolved. 

6) I shared this info with others on a Comcast forum.  Others with this issue are sharing that they've got the Netgear CM500V as well.  One person shared their Netgear CM500V modem's event logs which included several critical TFTP and SYNC Timing Synchronization failures.  

https://forums.xfinity.com/t5/Home-Phone-Service-Equipment/Caller-cannot-hear-me-but-I-can-hear-the-...  

7) I have firmware version V1.01.10 - which is the latest (according to the 1st site above) - installed on the Netgear CM500V modem.  I have reset the Netgear CM500V modem to factory default and the firmware version has not changed.  I am curious when firmware version V1.01.10 was released to Comcast... because if it was released to Comcast within the past 6 months then perhaps it is the cause of the issues; however, if it was released a long time ago then perhaps Comcast is the cause of the issues (even though the issue is not occuring on the Arris TG1682G modem).

😎 I purchased another 'new' Netgear CM500V modem from Walmart online and I'm waiting for it to arrive.  I expect this 'new' Netgear CM500V modem to have this issue.    

Please help

Thanks in advance

SF

[sferrell615 · Accepted solution]

The steps below resolved the problem for me. 

The problem has been resolved for several months and has not returned.

1. browse to https://connect.xfinity.com/voice/settings/callforwarding 
2. login (if needed; perhaps re-browse to the address above thereafter)
3. remove all numbers except 'home phone' 
4. disable 'home phone'
5. enable 'home phone'
6. perhaps remove 'selective call forwarding' numbers (?) 

I did not test right-after doing this... I tested 1-2 weeks later (at which point it worked as expected).  Therefore I am not certain that this is the fix but I have had a ticket open with Netgear for several months (nothing has been done) and no one has offered other solutions.  

[FURRYe38]

Contact the ISP to have them help you on this. Be sure all phone lines and phone line cabling is fully working correctly. The ISP should be able to help here. 

[sferrell615]

I do not disagree with the word "should" in "should be able to help"; however, we have reached out to the ISP (Comcast) and had the ISP send a tech to where we live to no avail... so if Netgear could provide 'an ounce' of support then it would be appreciated.  

1) Does performing a Factory Reset restore the original firmware version that was installed on the Netgear modem when I purchased it?  If so then the Netgear firmware version has not changed over the 2 years that I have owned the Netgear modem.  If that is the case then is it true that nothing has changed on the Netgear modem and becaues a large number of people are having this issue then it is likely that Comcast changed something on their network to cause the Netgreat modem this issue (despite not causing other modems e.g. Arris) the same issue.

2) Is it possible to find out when Netgear firmware versions for Netgear modems were released?  I do not trust that if I asked Comcast this question I would receive an accurate result. 

3) Is it possible to install an older version of a firmware on a Netgear modem?  

4) Has this issue ever occured with a modem and ISP before and if it did then what was the solution?   

Thanks in advance

SF

[FURRYe38]

"3) The Netgear CM500V modem has worked for me (internet and phone) for almost 2 years.

4) For the last 2 months when another Comcast caller from a landline phone calls my Comcast landline phone that caller cannot hear me. "

This being mentioned, if this has been working, then them modem would be probably fine. Something else has change, i.e. ISP service, phone line cabling or junction boxes may have got changes or possible water got into the box(s). Something the ISP needs to look closer into. Check the phone system, have the ISP ensure the configuration of the modem is set correctly. Check the phone devices connected to the modem as well. Swap out for different phone devices to test. 

[sferrell615]

I edited the original response via adding question 1.  

1) Does performing a Factory Reset restore the original firmware version that was installed on the Netgear modem when I purchased it?  If so then the Netgear firmware version has not changed over the 2 years that I have owned the Netgear modem.  If that is the case then is it true that nothing has changed on the Netgear modem and becaues a large number of people are having this issue then it is likely that Comcast changed something on their network to cause the Netgear modem this issue (despite not causing other modems e.g. Arris) the same issue.

We swapped coax lines from the Comcast junction box, we swapped phone-lines, we swapped phones (connected direct to the Netgear modem), we reprovisioned the Netgear modem, we rebuilt the Netgear modem on the 2nd phone line, and we reset the Netgear modem to factory default.  None of these changes resolved the issue.  Once we replaced the Netgear modem with the Arris modem the issue was resolved.  So IMO it is either 1) a change to the Netgear modem (e.g. firmware) or a change to the Comcast network which appears to 'just' cause the Netgear modem the issue (because the Arris modem does not have the issue).

Hence the reason that I am interested in determining if something has changed on the Netgear modem (e.g. firmware).   

Thanks in advance

SF

[FURRYe38]

---

@sferrell615 wrote:

I edited the original response via adding question 1.  

1) Does performing a Factory Reset restore the original firmware version that was installed on the Netgear modem when I purchased it? No.

If so then the Netgear firmware version has not changed over the 2 years that I have owned the Netgear modem.  If that is the case then is it true that nothing has changed on the Netgear modem and becaues a large number of people are having this issue then it is likely that Comcast changed something on their network to cause the Netgear modem this issue (despite not causing other modems e.g. Arris) the same issue. Anything is possible when it comes to ISPs. 

We swapped coax lines from the Comcast junction box, we swapped phone-lines, we swapped phones (connected direct to the Netgear modem), we reprovisioned the Netgear modem, we rebuilt the Netgear modem on the 2nd phone line, and we reset the Netgear modem to factory default.  None of these changes resolved the issue.  Once we replaced the Netgear modem with the Arris modem the issue was resolved.  So IMO it is either 1) a change to the Netgear modem (e.g. firmware) or a change to the Comcast network which appears to 'just' cause the Netgear modem the issue (because the Arris modem does not have the issue).

Hence the reason that I am interested in determining if something has changed on the Netgear modem (e.g. firmware).   

I would have the ISP look at the FW update history. Again, if the modem had been working up till recently, a FW update may have changed that...

---

[sferrell615]

Ok. Will do.

No clue how often issues occur with modems and ISPs but it'd be nice (for troubleshooting purposes) if the Netgear modem at the least listed when it's firmware was last updated and even better if it listed it's firmware install history.

Thanks for your quick responses.
SF

[FURRYe38]

FW updates are something that all cable modem ISPs control. Modem mfrs don't have much control if any over this. 

[sferrell615]

Again while I appreciate your response and I'm OK with accepting that the ISPs are responsible for deploying the firmware releases, the ISPs do not create the firmware releases. Netgear creates the firmware releases for the Netgear CM500V modem including the latest firmware version V1.01.10 release. Netgear "should" be able to look at their firmware version releases and determine if it was within the last 6 (or so) months.

I received the new CM500V modem and it's having the same exact issues as the old CM500V modem.
As a reminder, in between these 2 CM500V modems (which both had this issue) I was using an Arris TG1682G modem which did not have this issue. Do you see a pattern?
I called Netgear last night at 10pm EST. The 1st call took 1.5 hours to speak to the right dept (CM500V voice) then the call dropped on the other end and I was not called back. I called Netgear again and after another hour I got thru to the right dept. The tech said he did not know when the last CM500V firmware version was released to Comcast but others were reporting this problem and he'd get back to me within 1 or 2 days via email and/or phone.
TBC

[FURRYe38]

You'll have to work with NG support on this then. This is something the forums can't help with. Good Luck. 

[sferrell615]

Does anyone know how long it usually takes for Netgear support to get back to them?

I waited a total of 3 hours to speak to someone at Netgear support.  I spoke to him for 5 minutes (tops).  He recognized that other people have reported the problem.  He said that he'd call and/or email me within 1-2 days.  It's now been 11 days and 'nothing'. 

I've followed up on the Netgear support ticket twice.

I recognize that this is a fairly complex problem; however, if Netgear support could at least let me know that they've contacted the ISP (Comcast) or begun reviewing the firmware release history or 'anything' it would be appreciated.  

I always thought that Netgear was a premium brand... I'm starting to question that.  

BTW please do not close this ticket as I fully intend to provide the solution once a solution has been achieved.  

[sferrell615]

It took 20 days but I received a response in my Netgear support ticket... asking me for basic info that I provided in the past... along with event logs. 

I reset the modem, re-created the issue, captured the logs, reset the modem, performed a similar task that does not cause the issue, captured the logs.  Explained what I did in the Netgear support ticket and attached the requested screenshots and logs in a zip.  

I hope to respond again with news in less than 20 days 🙄

[sferrell615]

just a status update... 

a couple of days later the netgear support re-asked for the modem's log messages which i re-provided.  

today i was informed that the netgear engineering team is investigating the issue.  

[sferrell615]

netgear customer support at it's finest...

NETGEAR Support

2020-12-29 0:40:58

Dear Scott, Good day! We are still looking into this issue. We hope to fix this issue in our next update. We really appreciate your patience and co-operation. Thank you again for your letting us know about this issue, as this will help us improve our products. Have a great day! Regards, Praveen Netgear

then 1-2 days later...

This case has already been closed, please log a new support request if you require further help.

in total, i provided 8 responses to the netgear customer support rep over 1.5 months and out of nowhere the ticket was closed.

now, the problem has been resolved for 2 weeks; however, since it appears that netgear has done nothing to resolve the problem and i did perform a change on comcast's end (the ISP) i wanted netgear to continue to investigate for others that have this problem (again, according to the comcast forum [mentioned in a previous post above]).  

the change that i made on comcast's end was to log into my comcast account and remove all numbers being forwarded to including disabling the home number, saving, re-enabling the home number, saving.  i did not test to see if this issue was resolved right after i made this change, so when i realized that this problem was resolved i didn't know if it was resolved because of a netgear change or the comcast change.  

one person on the comcast forum said that this comcast change resolved the problem for a local comcast number but not a long-distance comcast number.  

i don't plan to re-open a ticket with netgear... unless people think that i should.  let me know.

[FURRYe38]

it would be wise to keep in contact with NG support. Theres nothing we can do to help you out here in the forums. 

Good Luck. 

[sferrell615]

understood. 

i opened a new case with netgear customer support and referenced the old case number.  

the latest info from the comcast forum is that someone said that they had this modem (cm500v) for 2 years (as i did), started having this problem in the past couple of months (as i did), called comcast but the problem remained (i.e. nothing was done to resolve the problem), and now the problem is gone.  so i believe it is possible that something changed on this modem (from netgear thru comcast) or on the comcast network / accounts; however, i don't know what yet.   

please keep this thread open and i'll continue to provide updates.  

[sferrell615 · Accepted solution]

The steps below resolved the problem for me. 

The problem has been resolved for several months and has not returned.

1. browse to https://connect.xfinity.com/voice/settings/callforwarding 
2. login (if needed; perhaps re-browse to the address above thereafter)
3. remove all numbers except 'home phone' 
4. disable 'home phone'
5. enable 'home phone'
6. perhaps remove 'selective call forwarding' numbers (?) 

I did not test right-after doing this... I tested 1-2 weeks later (at which point it worked as expected).  Therefore I am not certain that this is the fix but I have had a ticket open with Netgear for several months (nothing has been done) and no one has offered other solutions.