new modem needed?

Updating this now the the issues I've had are resolved:

Tech came out a week and a half ago and removed what he called a 'filter' that was connected to my line at the pole. Said it doesn't cause issues for Xfinity modems so that's how it can go unnoticed, but it shouldn't have been on there. Since then it has worked much better, I have only gotten a few modem errors in the last week or so as opposed to dozens every hour (with occasional modem reset) and no longer have huge ping spikes when gaming.

Glad it has been fixed, a little peeved at the process because different representatives on the phone told me different things with the same info. One told me that their readings indicated a connection issue while another told me it was certainly my modem (obviously incorrect in retrospect). Without my own research and the help of people on here I would not have had the knowledge to be confident and persistent in getting a tech out here rather than replacing my equipment.

Also, since the fix the modem now has multiple upstream channels, so definitely was a connection issue there

@user_93f883 

Yes, technically using a modem that is not approved for your speed tier can cause a host of problems.

But please, please take a quick browse thru this forum and see just how many people are in your position, ie they move, comcast tells em they need new gear, they get one, two, sometimes three new modems, and yet their problems remain.

Sadly it's a very difficult position to be in. Comcast won't even begin to troubleshoot until you get an approved modem, and then every time your service fails to improve they will say your new modem is defective, and you really need to rent a gateway from them.

Sorry to be such a party pooper, but the more time I spend in these forums the sadder it makes me.

On the up side, there are some very helpful folks here, so posting your up and downstream levels plus your logs, might get you the help you need.

Please make sure you redact MAC & IP addresses from the logs.

HTH

@zip21222​ Thanks for the response. I was/am worried about them giving me the equipment runaround. The phone tech actually cancelled a service appointment I had scheduled, which is annoying since them coming out would have helped attacked the problem from multiple angles. I was hoping that I wouldn't have any issues because Comcast is my only provider for the area, and ISPs are notoriously painful to work with (especially when not renting their equipment), but wasn't so lucky.

Power Levels & other info (at this moment the levels are lower but I have seen them as high as 9.3):

Logs snippet (there is much more, seems to be a set of errors every 10 minutes or so:

@user_93f883 

[sigh] was in almost your exact situation a couple years ago, so I know...

first, could you post your upstream numbers also? Need to see both sides.

The downstream power levels are on the high side, but in-spec, the SNRs are in-spec, and zero correcteds and uncorrecteds is a good sign.

I'm far from a docsis expert, but those log entries don't look (to me at least) like the kinda stuff that would cause your problems.

I don't see any disconnects or restarts, which are the most common red flags (to me).

Let's see what, if anything, the upstream numbers tell us.

HTH

gotcha, here is my upstream:

@user_93f883 

well, everything's to spec technically.

the first thing I'd do is check for plant issues (cables, splitters,etc) in any spaces that are accessible to you.

Take a look at the pinned 'Internet Troubleshooting Tips' topic in this forum, in particular the section from 'Inspect cabling' down to 'Check the quality/status of all splitters'.

If you don't find anything, you could try a forward path attenuator to lower your downstream power without negatively effecting upstream power.

This is the one I use.

HTH

@zip21222 

Thanks for the pointers. I will check out that topic

As for the cable checking, the coax cable goes directly from the comcast box to my modem, no splitters or other such connections.

I will probably check out an attenuator if nothing else crops up, as that would be far less expensive than getting a new modem.

... SB6183 ... I know that 400 is pushing the capabilities of the modem I have ...

You're not "pushing the capabilities", you're trying to use a modem on a speed tier for which it is not approved. https://www.xfinity.com/support/devices says the SB6183 is approved for use with plan speeds "Up to 373 Mbps". Using devices on Internet speed tiers for which Comcast has not approved them tends to produce unexpected results, often speeds well below the manufacturer's ratings. It would be best to upgrade the device, or to choose a lower plan speed for which the device is approved.

...  here is my upstream ...

Something's wrong here. There should be at least 3 upstream channels locked. The drop at your new location may require attention.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

@BruceW 

Thanks for the info, I have been trying to get onto that page you linked all day but it never finishes loading for me (have tried on my network and mobile data) to see the info for my modem. I am surprised by this as the manufacturer rates it for 600, so not even being able to take 2/3 the rated is rather disappointing.

As for the upstream, double checked my modem page to be sure and yup, there is only one upstream. Not sure how concerned I should be about it. Seems like it'd be pulling teeth to get a tech out for that.

Also, it seems the logs and my packet issues may be linked. Here is a log output and ping test output where the critical errors seem to coincide with an instance of extremely high ping (modem timestamp is an hour behind)

I haven't been actively cross referencing these, so I will keep watching to see if there is a pattern

Log:

Ping:

10/27/2022 4:53:04 PM - Reply from 8.8.8.8: bytes=32 time=18ms TTL=56
10/27/2022 4:53:05 PM - Reply from 8.8.8.8: bytes=32 time=19ms TTL=56
10/27/2022 4:53:06 PM - Reply from 8.8.8.8: bytes=32 time=18ms TTL=56
10/27/2022 4:53:07 PM - Reply from 8.8.8.8: bytes=32 time=17ms TTL=56
10/27/2022 4:53:08 PM - Reply from 8.8.8.8: bytes=32 time=20ms TTL=56
10/27/2022 4:53:11 PM - Reply from 8.8.8.8: bytes=32 time=1798ms TTL=56
10/27/2022 4:53:11 PM - Reply from 8.8.8.8: bytes=32 time=19ms TTL=56
10/27/2022 4:53:12 PM - Reply from 8.8.8.8: bytes=32 time=18ms TTL=56
10/27/2022 4:53:13 PM - Reply from 8.8.8.8: bytes=32 time=21ms TTL=56
10/27/2022 4:53:14 PM - Reply from 8.8.8.8: bytes=32 time=19ms TTL=56
10/27/2022 4:53:15 PM - Reply from 8.8.8.8: bytes=32 time=39ms TTL=56

EDIT: Just got another laggy packet and yup, there is a corresponding error log

EDIT 2: Now have 4 logs and 4 laggy packets that correspond to each other

UPDATE: Sometime during my troubleshooting my internet speed drastically improved (from 90ish mbps to 400ish) but the packet issue remains. This makes me think that it is a comcast problem rather than my modem, as even after reverting to my original network setup/configuration the higher speed remains.

Awesome!!

Crossing my fingers that it stays that way!