Community Forum

Only 1 Upstream Channel Bonded

Frequent Visitor

Only 1 Upstream Channel Bonded

Hello

 

I recently moved to the upstiars unit in the same building and transferred my internet service accordingly. 

 

At first, I was having connectivity issues with a steady blinking u/s light with all other green & solid. The agent on the phone was able to see my modem and send a refresh, but I was not able to connect thru to the internet. 

 

Finally, the modem was able to connect. My speed is testing at 70/5, which I'm satisfied with.. but after digging I found my modem is only bonding to one upstream channel and has numerous critical errors. 

 

See attached. Any thoughts?

 

Thank youlogfile.pngdetail.png

Expert

Re: Only 1 Upstream Channel Bonded

Can't see your pics. Since you are a new poster, it needs to be approved by a Forum Admin. That could take some time. In the interim you could try hosting them at one of those free third-party pic hosting sites like Imgur or Photobucket and post the link to it here.



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!
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

@EG Thanks for the heads up! Looks like they've been approved now.

Expert

Re: Only 1 Upstream Channel Bonded

What is the exact make and model number of the modem ? Have you first tried power-cycling / re-starting it ? 



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!
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

Hi @EG  it's a Netgear CM500-100NAS

 

I've power cycled and reset more than once and the same issue persists.

 

I've been in the new apartment for over a week now and have no complaints about the connection.. but can't help that the steady blinking U/S light on my modem is bothering the heck out of me!!

 

Thanks for any advice on how to resolve this.. based on my research it seems like it could be the integrity of the cabling, splitters, etc..? Not sure how much luck I'll have getting Comcast to take a look if I'm not having any "real" issues. 

 

Thanks

Matt

Expert

Re: Only 1 Upstream Channel Bonded

Try hard resetting the device to factory defaults by pressing and holding in the recessed reset button on the rear for 30 seconds. This can sometimes help it to re-range for more channels.



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!
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

@EG  thanks again for your continued attention.

 

I was reluctant to power cycle my modem; since I've had this problem it's been difficult to get the modem to connect.

 

I hard reset the modem by pressing the button on the back. The modem attempted to connect and failed for about 15 minutes before finally gaining a solid internet connection. The modem settings still show only 1 U/S channel bonded. 

 

Again, glad this isn't creating a connection issue, but I'm concerned that anytime I need to routinely power cycle it seems to be a hit or miss as far as getting my connection back. 

Expert

Re: Only 1 Upstream Channel Bonded

The upstream power is a bit 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, channel un-bonding, and latency problems.

There may be an upstream channel / return path impairment somewhere. 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. Good luck !



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!
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

@EG thanks again for your support!

 

I attempted to trace my connections back to the street. Unfortunately, over the years tenants have had multiple satelite dishes leaving a mess of coax all over. There also seems to be 4 feeds coming from the pole (for a 3 unit home). It's possible 3 are Comcast feeds and one of the tenants switched to RCN and they ran a new drop. 


The only thing I was able to accomplish was deleting a splitter outside that had one end going to one of my rooms, and the other had a cable cut off. I figured this could be a source of interference. I still have a steady blinking U/S light and only 1 channel bonded, but never power cycled or hard reset after deleting the splitter. (I'm worried about not being able to regain my connection as each time it's very dicey). The modem is still showing T3/T4 timeouts in the error logs, among multiple other errors every few seconds or minutes. 

 

If @EG  or anyone else thinks another hard reset after removing this one splitter may benefit, I'm willing to roll the dice again. Otherwise, at this point I'll suppose I'll live with it until it becomes a larger issue. My download and upload speeds are fine, latency is testing at ~12ms, and I only experience drops when rebooting the modem.. once it's up and running for an hour or so it's stable. 


Not worth me going through the hassle of having a tech come out just yet, although I welcome any additional feedback, suggestions, etc.

 

Thank you!

Diamond Problem Solver

Re: Only 1 Upstream Channel Bonded

It’s possible, especially when you describe the outside building wiring, that the maintenance department has put a high pass filter on your drop. They do that to block excessive noise/interference from going back into the plant. With that type of filter in place, your modem would only show 1 upstream channel. You’ll need a tech out to remove it if it’s there. Normally there would be notes on your account that it’s there

I am a Retired Official Comcast Employee
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

@CCAndrew  Thanks! I noticed after each drop there was an inline filter (the same width as the coax connector). 

 

Any reason why I couldn't remove this on my own and see how it affects things? If we're talking about the same thing, it seems like just a barrel shaped filter that threads and couples the coax connections. 

Expert

Re: Only 1 Upstream Channel Bonded

Can you take a pic(s) of it / them and post it / them.



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!
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

Hi @EG 

 

Sure thing.. Attached are some photos of the inline filters outside. I believe the lines servicing my home are the 1 photo with NO filter and the other photo with the red sticker on it. 

 

It does seem like two drops from the pole are coming into my unit. Not sure if there would ever be a reason for this, or if one is inactive or belonging to another provider, such as RCN. 

 

I believe the filter with the red sticker is what's feeding my current connection.

 

Thanks!

IMG-4304.JPG
IMG-4305.JPG
IMG-4303.JPG
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

It seems like at least the filter with the red sticker could be a "MoCA" filter, which I'm researching now.  

Diamond Problem Solver

Re: Only 1 Upstream Channel Bonded

The last picture is the high pass, first is the moca filter, second is ground block

I am a Retired Official Comcast Employee
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

@CCAndrew  The one with the high pass I believe is for my neighbor. I took pics of all of the drops to be safe. 

 

The one with just the ground block comes straight from the pole, then up into a bedroom in my unit.


The one with a MoCA also seems to go into my unit where I'm currently plugging in.

 

Would the MoCA have any impact on DOCSIS or the issues I'm having? Seems like it shouldn't based on my limited research. 

Diamond Problem Solver

Re: Only 1 Upstream Channel Bonded

Theoretically the moca filter could, you could always try hooking your modem at that spot before the moca filter. Could be a high pass at the pole too. Could be your modem too. That’s the fun of troubleshooting.

I am a Retired Official Comcast Employee
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
Frequent Visitor

Re: Only 1 Upstream Channel Bonded

Thanks @CCAndrew . Fun indeed.

 

I only moved from the downstairs unit to upstairs in a 3 family home. The modem was functioning just fine before so it has to be something different with this drop..  So step one I'll test without the MoCA.

 

Not sure if it's worth mentioning but at the present time I'm only utilizing internet services; no phone for cable TV. Seems like the MoCA has more to do with on-demand/streaming but this is based on my amateur research. 

 

Still scratching my head as to why it appears there are two feeds from the pole into my unit; one in the front without any sort of filter and one in the rear with the MoCA inline.