Extremely slow upload speed (0.5 Mbps) and some T3 time-out error logs.

My home internet started to experience slowness when on videoconference or uploading pic/files about a week ago. The download speed is normal though. An agent from Xfinity came to my house and checked the signal. He ruled out the problems from cables, and said the upstream power is too low (< 45dBmV), and suggested me to upgrade my modem (Arris sb6183). I then got the new one (SB8200) and still got the same low upload speed issue. So I don't think the problem is the modem. I have spoken to at least 3 specialists and all of them have no idea what's going on. The only useful info I heard is all said they receive no or weak signals from my apartment.

Here are some upstream info.

Upstream Bonded Channels

Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	3	Locked	SC-QAM Upstream	30300000 Hz	6400000 Hz	43.0 dBmV
2	1	Locked	SC-QAM Upstream	17300000 Hz	6400000 Hz	43.0 dBmV
3	2	Locked	SC-QAM Upstream	23700000 Hz	6400000 Hz	43.0 dBmV
4	4	Locked	SC-QAM Upstream	36700000 Hz	6400000 Hz	43.0 dBmV

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Responses

CCAndrew

Gold Problem Solver

•

25.9K Messages

5 years ago

There’s a difference between upstream power signal levels, which you posted, and upload speeds which you didn’t post. Your levels posted are in spec. You didn’t post what your actual speeds are and what you’re expecting paying for. Did you do a speed test? Your title thread mentioned it and logs but never posted, or the downstream levels. Are you checking from your modem or from your router?

sumash

Frequent Visitor

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6 Messages

5 years ago

Snic8

New Poster

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3 Messages

5 years ago

I was having the extact same problem with tons of uncorrectables on all of my channels. Comcast replaced the line coming into my house and now I only have errors on channel 48. This past week, it has been really bad. The internet is so intermittent that it's borderline unuseable. I am using the SB8200. I contact comcast and they say that it's a modem problem. I contact Arris and they say that it's a comcast problem.

Startup Procedure

Procedure	Status	Comment
Acquire Downstream Channel	525000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Configuration File	OK
Security	Enabled	BPI+
DOCSIS Network Access Enabled	Allowed

Downstream Bonded Channels

Channel ID	Lock Status	Modulation	Frequency	Power	SNR/MER	Corrected	Uncorrectables
20	Locked	QAM256	525000000 Hz	7.0 dBmV	41.2 dB	0	0
17	Locked	QAM256	507000000 Hz	6.7 dBmV	41.1 dB	0	0
18	Locked	QAM256	513000000 Hz	6.4 dBmV	41.0 dB	0	0
19	Locked	QAM256	519000000 Hz	6.4 dBmV	41.0 dB	0	0
21	Locked	QAM256	531000000 Hz	7.1 dBmV	41.2 dB	0	0
22	Locked	QAM256	537000000 Hz	7.0 dBmV	41.3 dB	0	0
23	Locked	QAM256	543000000 Hz	7.2 dBmV	41.2 dB	0	0
24	Locked	QAM256	549000000 Hz	7.8 dBmV	41.4 dB	0	0
25	Locked	QAM256	555000000 Hz	7.5 dBmV	41.3 dB	0	0
26	Locked	QAM256	561000000 Hz	7.6 dBmV	41.3 dB	0	0
27	Locked	QAM256	567000000 Hz	7.9 dBmV	41.3 dB	0	0
28	Locked	QAM256	573000000 Hz	7.9 dBmV	41.4 dB	0	0
29	Locked	QAM256	579000000 Hz	7.7 dBmV	41.2 dB	0	0
30	Locked	QAM256	585000000 Hz	8.0 dBmV	41.2 dB	0	0
31	Locked	QAM256	591000000 Hz	8.4 dBmV	41.5 dB	0	0
32	Locked	QAM256	597000000 Hz	8.3 dBmV	41.3 dB	0	0
33	Locked	QAM256	603000000 Hz	8.3 dBmV	41.3 dB	0	0
34	Locked	QAM256	609000000 Hz	8.5 dBmV	41.4 dB	0	0
35	Locked	QAM256	615000000 Hz	8.6 dBmV	41.3 dB	0	0
36	Locked	QAM256	621000000 Hz	8.5 dBmV	41.4 dB	0	0
37	Locked	QAM256	627000000 Hz	8.7 dBmV	41.3 dB	0	0
38	Locked	QAM256	633000000 Hz	8.9 dBmV	41.5 dB	0	0
39	Locked	QAM256	639000000 Hz	8.7 dBmV	41.4 dB	0	0
40	Locked	QAM256	645000000 Hz	8.8 dBmV	41.5 dB	0	0
41	Locked	QAM256	651000000 Hz	8.9 dBmV	41.5 dB	0	0
42	Locked	QAM256	657000000 Hz	9.1 dBmV	41.7 dB	0	0
43	Locked	QAM256	663000000 Hz	8.9 dBmV	41.5 dB	0	0
44	Locked	QAM256	669000000 Hz	8.8 dBmV	41.6 dB	15	0
45	Locked	QAM256	675000000 Hz	9.2 dBmV	41.5 dB	0	0
46	Locked	QAM256	681000000 Hz	8.6 dBmV	41.5 dB	0	0
47	Locked	QAM256	687000000 Hz	8.9 dBmV	41.7 dB	0	0
48	Locked	Other	850000000 Hz	7.2 dBmV	39.5 dB	621900572	0

Upstream Bonded Channels

Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	3	Locked	SC-QAM Upstream	30300000 Hz	6400000 Hz	44.0 dBmV
2	1	Locked	SC-QAM Upstream	17300000 Hz	6400000 Hz	45.0 dBmV
3	5	Locked	SC-QAM Upstream	41200000 Hz	1600000 Hz	43.0 dBmV
4	2	Locked	SC-QAM Upstream	23700000 Hz	6400000 Hz	45.0 dBmV
5	4	Locked	SC-QAM Upstream	36700000 Hz	6400000 Hz	44.0 dBmV

sumash

Frequent Visitor

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6 Messages

5 years ago

Thanks for the information. That's very useful. Do you still have the same problem after they replaced the line to your house? I have seen other people's log also shows channel 48 having lots of errors (It seems to be normal though I don't know why)

The following was what I experienced as well.

@Snic8 wrote:
I contact comcast and they say that it's a modem problem. I contact Arris and they say that it's a comcast problem.

Another tech came yesterday and did a full diagnosis on all possible causes, and concluded it's Xfinity's problem (in the box outside my apartment). They are sending someone to fix it.

sumash

Frequent Visitor

•

6 Messages

5 years ago

The last agent said they will fix it in 3 days. Still, no response from Xfinity and the internet cannot be worse, with a few outages in the past few days. really disappointed.

Your Home Network

sumash

Extremely slow upload speed (0.5 Mbps) and some T3 time-out error logs.

CCAndrew

sumash

Snic8

sumash

sumash

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