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200mbps Plan Capped Randomly at 30 mbps EVERY DAY

New Poster

200mbps Plan Capped Randomly at 30 mbps EVERY DAY



We have an Arris Surfboard SB6190 modem and a Netgear Nighthawk R6700. We are on a 200mbps download plan.


We get around 150mbps throughout the day when everything is working. More often we will go for hours limited to 30mbps.


I'm starting to notice this is happening around 7pm every day, lasting through midnight and sometimes through the morning. We will also be capped at 30mbps randomly throughout the day for several hours.


This has been observed and confirmed by an Xfinity internet tech support agent over the phone who looked at our "Historical Plots" for the last 6 days and noted the random "drastic" drops in speed the line is providing to our modem.


This 30mbps cap applies to all devices in the home, regardless of wifi or Ethernet connection. I have direct connected my laptop to both the router and the modem to confirm the Ethernet connection directly from the modem is also reflecting the 30mbps cap.


Modem Upstream/Downstream details:

Downstream(32 channels):

When the internet is capped at 30mbps, Channel 5 is "Not Locked". Currently the internet is not capped at 30mbps, Channel 5 is "Locked" but has 1700382 Correctable and 1216596 Uncorrectables. 

Channel 6 has 22,665,577 Correctables and 21,922,667 Uncorrectables


Upstream(4 Channels):

All 4 channels are "Locked".

An Arris tech representative noted the power levels for the upstream channels are too low and need to be corrected by Xfinity. The range should be 45-52dBvm, the range the modem is receiving is 37-42dBvm.


What could be causing this?

Diamond Problem Solver

Re: 200mbps Plan Capped Randomly at 30 mbps EVERY DAY

Post your levels and don’t believe Arris

I am a Retired Official Comcast Employee
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New Poster

Re: 200mbps Plan Capped Randomly at 30 mbps EVERY DAY

Downstream Bonded Channels
ChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectedUncorrectables
1Locked256QAM37675.00 MHz5.60 dBmV38.61 dB484113
2Locked256QAM9507.00 MHz7.80 dBmV40.37 dB1080138
3Locked256QAM10513.00 MHz7.90 dBmV40.37 dB985158
4Locked256QAM11519.00 MHz7.50 dBmV40.37 dB924138
5Locked256QAM12525.00 MHz7.60 dBmV37.64 dB17004951216609
6Locked256QAM13531.00 MHz7.50 dBmV40.37 dB2266570121922667
7Locked256QAM14537.00 MHz7.20 dBmV40.37 dB790144
8Locked256QAM15543.00 MHz7.20 dBmV40.37 dB665137
9Locked256QAM16549.00 MHz6.80 dBmV40.95 dB641168
10Locked256QAM17555.00 MHz6.60 dBmV40.37 dB592167
11Locked256QAM18561.00 MHz6.50 dBmV38.98 dB1059299
12Locked256QAM19567.00 MHz6.20 dBmV38.98 dB60090
13Locked256QAM20573.00 MHz6.10 dBmV38.98 dB45840
14Locked256QAM21579.00 MHz5.80 dBmV38.61 dB49143
15Locked256QAM22585.00 MHz5.60 dBmV38.98 dB7312188
16Locked256QAM23591.00 MHz5.70 dBmV40.37 dB8122000
17Locked256QAM24597.00 MHz5.40 dBmV38.98 dB8972860
18Locked256QAM25603.00 MHz5.20 dBmV38.98 dB6571039
19Locked256QAM26609.00 MHz5.40 dBmV38.98 dB619141
20Locked256QAM27615.00 MHz5.60 dBmV38.98 dB549165
21Locked256QAM28621.00 MHz5.60 dBmV38.98 dB557140
22Locked256QAM29627.00 MHz5.90 dBmV38.98 dB480138
23Locked256QAM30633.00 MHz5.90 dBmV38.61 dB474173
24Locked256QAM31639.00 MHz6.00 dBmV38.61 dB462134
25Locked256QAM32645.00 MHz6.00 dBmV38.90 dB432161
26Locked256QAM33651.00 MHz5.90 dBmV39.20 dB433156
27Locked256QAM34657.00 MHz5.90 dBmV38.90 dB445155
28Locked256QAM35663.00 MHz5.90 dBmV38.60 dB381121
29Locked256QAM36669.00 MHz5.80 dBmV38.90 dB459115
30Locked256QAM38681.00 MHz5.60 dBmV39.20 dB45178
31Locked256QAM39687.00 MHz5.30 dBmV39.20 dB39047
32Locked256QAM40693.00 MHz5.10 dBmV38.60 dB3538


Upstream Bonded Channels
ChannelLock StatusUS Channel TypeChannel IDSymbol RateFrequencyPower
1LockedATDMA65120 kSym/s30.10 MHz37.75 dBmV
2LockedATDMA85120 kSym/s17.30 MHz37.50 dBmV
3LockedATDMA75120 kSym/s23.70 MHz37.00 dBmV
4LockedATDMA55120 kSym/s36.50 MHz37.50 dBmV
New Poster

Re: 200mbps Plan Capped Randomly at 30 mbps EVERY DAY

Update: (Short Version) A "bucket team" technician was sent to our area to replace very old connections on the utility poles in the neighborhood serving our building. This seems to have fixed the issue.


(Long Version)

After being put in contact with someone from the executive office, she was able to schedule another technician who was the first one to show up with SOME background information given to them. He was the first to knock on our door without saying "I don't have any notes on why I am here, tell me what's happening." 


He confirmed our building wiring is fine and capable of receiving and distributing the maximum signal. He was able to see the signal our building was receiving over the last few days and confirmed the problem is not our modem, or router, or wiring. The issue is coming from the "node" on a nearby utility pole or something. When he opened a ticket for the "bucket team" to come out and check the "node" he found there were already 14 complaints about a similar internet performance issue coming from the same "node", which serves hundreds of people in the area.


A few days later a "bucket team" member knocked on our door and reported he had been up in the "bucket" checking out the "node" and other junction boxes on utility poles. He found some vital connectors that could have been 30 years old by the looks of them and were likely the cause. He replaced all the old connectors and took before/after shots for his report. 


Since then we haven't had internet issues. It's only been 4 days, but it used to act up multiple times a day.