Visitor
•
8 Messages
ARRIS G36 Downstream and Upstream Signal Levels
Hello!
I recently ditched my modem rental and purchased an ARRIS G36 modem from BestBuy (new). I also decided to upgrade to Gigabit because the modem appeared to support it AND was listed as supported on the Comcast Xfinity website.
However, I started noticing almost immediately that while my speeds were good, my connection was unstable during Zoom calls and stuff would just drop randomly. Similarly, WiFi calling on my iPhone stopped working well. Please note that during these drops the modem does not reboot itself. It just drops for a split second and comes back almost immediately.
I should mention we do not have TV or Phone service, only internet. I spoke with ARRIS customer support, and fairly quickly they were able to identify the issue as a problem with the Upstream signal levels being out of range. They mentioned that they should range from 45 to 51 considering there are 3 upstream channels. I was getting an 40 for each channel, which logically to me seems to be the problem, so I decided to give Xfinity a call. Long story short, they tried a bunch of steps and decided to send a tech out (who will be here Thursday) and they will hopefully be able to troubleshoot the signal.
However, I started Googling and I noticed some more discussions around similar issues with other ARRIS modems and Xfinity. This got me investigating my home setup, and I found out there were several unnecessary splitters and stuff (probably from the previous home owner) that I was able to remove pretty easily. The result is that I am now pretty much directly going into the line coming from the pole on the road. However, it seems like it might have resulted in me making the problem slightly worse?
Here are the latest readings:
Downstream | ||||||
Index | Frequency (MHz) | Power Level (dBmV) | SNR (dB) | Modulation | Lock Status | |
13 | 333 | 5.099998 | 40.946209 | QAM256 | Locked | |
14 | 339 | 4.900002 | 40.366287 | QAM256 | Locked | |
15 | 345 | 4.800003 | 38.983261 | QAM256 | Locked | |
16 | 351 | 4.699997 | 38.983261 | QAM256 | Locked | |
17 | 357 | 5 | 38.983261 | QAM256 | Locked | |
18 | 363 | 4.699997 | 40.366287 | QAM256 | Locked | |
19 | 369 | 4.5 | 38.605377 | QAM256 | Locked | |
20 | 375 | 4.099998 | 38.983261 | QAM256 | Locked | |
21 | 381 | 4.5 | 38.605377 | QAM256 | Locked | |
22 | 387 | 4.699997 | 38.983261 | QAM256 | Locked | |
23 | 393 | 5.099998 | 40.366287 | QAM256 | Locked | |
24 | 399 | 5.300003 | 40.366287 | QAM256 | Locked | |
25 | 405 | 4.800003 | 40.366287 | QAM256 | Locked | |
26 | 411 | 4.699997 | 38.983261 | QAM256 | Locked | |
27 | 417 | 4.5 | 40.366287 | QAM256 | Locked | |
28 | 423 | 5.099998 | 40.366287 | QAM256 | Locked | |
29 | 429 | 3.5 | 38.983261 | QAM256 | Locked | |
30 | 435 | 3.099998 | 38.605377 | QAM256 | Locked | |
31 | 441 | 3.5 | 38.983261 | QAM256 | Locked | |
32 | 447 | 3.400002 | 38.983261 | QAM256 | Locked | |
33 | 453 | 2.900002 | 38.983261 | QAM256 | Locked | |
34 | 459 | 3.099998 | 38.605377 | QAM256 | Locked | |
35 | 465 | 2.799999 | 38.605377 | QAM256 | Locked | |
36 | 471 | 2.5 | 38.605377 | QAM256 | Locked | |
Upstream | ||||||
Index | Frequency (MHz) | Power Level (dBmV) | Channel Type | Symbol Rate (KSym/sec) | Modulation | Lock Status |
3 | 21.2 | 33.270599 | US_TYPE_ATDMA | 5120 KSym/sec | 64QAM | Locked |
1 | 34 | 33.270599 | US_TYPE_ATDMA | 5120 KSym/sec | 64QAM | Locked |
2 | 27.6 | 33.270599 | US_TYPE_ATDMA | 5120 KSym/sec | 64QAM | Locked |
What really confuses me is how did my upstream signal get weaker as a result of removing splitters? And I can confirm these were splitters, not amplifiers or anything else. Another thing is, where is the OFFICIAL documentation on the specification for the ranges? I've seen numbers posted in the forums, better never a source article.
Any help would be greatly appreciated. Thank you!
Andyr1
Gold Problem Solver
•
8K Messages
3 years ago
Upstream signals are how loud it's talking back. The numbers will get lower as you remove splitters. I have heard sometimes that being too low can be an issue as it may not be loud enough to be heard over some noise. Only Comcast get check the noise level of upstream as the receiver determines that.
1
0
BruceW
Gold Problem Solver
•
26.3K Messages
3 years ago
Arris began saying that upstream power should be "at least 45 dBmV" more than two years ago. I don't know why, because it's complete nonsense. The upstream power levels are controlled automatically and continuously by Comcast's equipment and do not need to be above 45 dBmV. That's because, as long as upstream power is not maxed out, what's important as Andy has stated is not the level at the modem, it's the level (and quality) of the modem's signal as received at Comcast, which they attempt to keep as close as possible to 0 dBmV by adjusting the modem's transmit power. In fact, many customers have service that works perfectly fine with upstream modem power levels below 45 dBmV. Some even operate with the upstream below 35 dBmV.
The signal values you posted look OK. Can you post the modem's event log? Be sure to edit out any MAC addresses as Forum security processing considers them "personal information" and may prevent the event log from posting.
1
BruceW
Gold Problem Solver
•
26.3K Messages
3 years ago
That's a pretty messy log, suggesting a problem with your connection to Comcast. Since the signal stats look OK, the next step would be to call them at the phone number on your bill or 1-800-Comcast, or use one of the options on https://www.xfinity.com/support/contact-us/. It's not likely they can fix the problem remotely. If not, insist they send a tech out to identify the cause and correct it.
If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit unless you have their Service Protection Plan ( https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device or anything outside your home you shouldn't be charged.
1
0
BruceW
Gold Problem Solver
•
26.3K Messages
3 years ago
Too soon to tell. What do the signal stats look like? Does the modem report correctable/uncorrectable error counts?
1
0
BruceW
Gold Problem Solver
•
26.3K Messages
3 years ago
Thanks for the update. It doesn't get better than no errors! Here's hoping it continues to hold for you.
4
0
user_e3e9fa
Visitor
•
1 Message
3 years ago
So glad I found this article! We got a G36 and are experiencing all the problems mentioned in the original post. We came to the conclusion it is the router And actually ordered a Motorola MB8611. The previous Motorola was great but decided to replace it, as the signal was weak in some places of the house. The G 36 is a better signal strength but inconsistent signal, causing our connection to drip during meetings. The G36 is going back to the store this weekend!! Glad I Found this article, so excited to replace it. Two weeks of trouble shooting I two weeks too many!
0
0
googalabosh
Visitor
•
1 Message
3 years ago
Same issue here! Unfortunately, didn't find this article until after we have had the gateway for more than 30 days. So, now we can't return it to Best Buy. Fantastic! Comcast/Xfinity really needs to take this off their list.
1
0