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Seriously slow download speeds for 9 days now

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Seriously slow download speeds for 9 days now

Comcast did some scheduled maintenance in my area about 9 days ago and ever since then I have been getting intermittent and random slowdown of my download speed. Of course I got the usual runaround from the CSR rep at Comcast so I figured I would give the forums a shot to see if any of you could assist me in determining if the problem is with my modem (what comcast thinks) or with something that Comcast did to screw up my service when they did the maintenance 9 days ago (what I think).

 

Modem: Netgear CM400

My Provisioned Speeds: 150/10

 

Here is what my speedtest result and modem up/down stream settings look like when I am having issues and before I restart my modem:

 

Screenshot-2019-9-19 Speedtest by Ookla - The Global Broadband Speed Test.pngPing: 31ms - Download: 3.12mb/s - Upload: 11.70mb/s

 

Startup Procedure

Procedure

Status

Comment

Acquire Downstream Channel

711000000 Hz

Locked

Connectivity State

Ok

Operational

Boot State

Ok

Operational

Security

Enabled

BPI+

IP Provisioning Mode

Honor MDD

honorMdd(4)

 

 

 

Downstream Bonded Channels

 

Channel

Lock Status

Modulation

Channel ID

Frequency

Power

SNR

Correctables

UnCorrectables

1

Locked

QAM 256

33

669000000 Hz

-6.9 dBmV

36.8 dB

252

1339

2

Locked

QAM 256

34

675000000 Hz

-7.3 dBmV

36.8 dB

265

1313

3

Locked

QAM 256

35

681000000 Hz

-7.8 dBmV

36.6 dB

303

2136

4

Locked

QAM 256

36

687000000 Hz

-7.6 dBmV

36.8 dB

71

2935

5

Locked

QAM 256

36

693000000 Hz

-7.7 dBmV

37.0 dB

159

3196

6

Locked

QAM 256

38

699000000 Hz

-8.7 dBmV

36.8 dB

26

679

7

Locked

QAM 256

39

705000000 Hz

-8.7 dBmV

36.8 dB

13

1404

8

Locked

QAM 256

40

711000000 Hz

-9.1 dBmV

36.3 dB

9

638

 

 

 

Upstream Bonded Channels

 

Channel

Lock Status

US Channel Type

Channel ID

Symbol Rate

Frequency

Power

1

Locked

ATDMA

4

5120 Ksym/sec

16600000 Hz

46.0 dBmV

2

Locked

ATDMA

3

5120 Ksym/sec

23000000 Hz

46.0 dBmV

3

Locked

ATDMA

2

5120 Ksym/sec

29400000 Hz

46.0 dBmV

4

Locked

ATDMA

1

5120 Ksym/sec

35800000 Hz

46.0 dBmV

 

 

 

Current System Time: Thu Sep 19 20:41:16 2019

 

 

 

 

And here is what my speedtest result and modem up/down stream settings look like when I am NOT having issues and after I restart my modem:

 

 

Screenshot-2019-9-19 Speedtest by Ookla - The Global Broadband Speed Test(1).pngPing: 30ms - Download: 175.92mb/s - Upload 11.84mb/s

 

Startup Procedure

Procedure

Status

Comment

Acquire Downstream Channel

693000000 Hz

Locked

Connectivity State

Ok

Operational

Boot State

Ok

Operational

Security

Enabled

BPI+

IP Provisioning Mode

Honor MDD

honorMdd(4)

 
   

Downstream Bonded Channels

 

Channel

Lock Status

Modulation

Channel ID

Frequency

Power

SNR

Correctables

UnCorrectables

1

Locked

QAM 256

33

669000000 Hz

-6.9 dBmV

36.8 dB

239

527

2

Locked

QAM 256

34

675000000 Hz

-7.2 dBmV

36.8 dB

255

1328

3

Locked

QAM 256

35

681000000 Hz

-7.8 dBmV

36.6 dB

347

1407

4

Locked

QAM 256

36

687000000 Hz

-7.6 dBmV

37.0 dB

260

680

5

Locked

QAM 256

37

693000000 Hz

-8.1 dBmV

36.8 dB

217

1489

6

Locked

QAM 256

38

699000000 Hz

-8.6 dBmV

36.8 dB

241

626

7

Locked

QAM 256

39

705000000 Hz

-8.7 dBmV

36.8 dB

300

1523

8

Locked

QAM 256

40

711000000 Hz

-9.1 dBmV

36.6 dB

231

573

 
   

Upstream Bonded Channels

 

Channel

Lock Status

US Channel Type

Channel ID

Symbol Rate

Frequency

Power

1

Locked

ATDMA

4

5120 Ksym/sec

16600000 Hz

45.5 dBmV

2

Locked

ATDMA

3

5120 Ksym/sec

23000000 Hz

45.5 dBmV

3

Locked

ATDMA

2

5120 Ksym/sec

29400000 Hz

45.5 dBmV

4

Locked

ATDMA

1

5120 Ksym/sec

35800000 Hz

45.5 dBmV

 
   

Current System Time: Thu Sep 19 20:57:40 2019

 

System Up Time: 00:12:43

 

 

To be honest I do not see much difference in the up/down stream figures when my internet is working properly and when it's not so I don't know how useful that information is, but I included them anyway.

 

I do have a router, but I took it out of the equation and directly connected my modem to my computer via a Cat6 cable and that did not seem to change anything.

 

Trying different cables did not seem to make any difference either, nor did reseating the cable splitter.

 

The modem is warm, but not hot and feels the same temp even when everything is working fine.

 

I also connected directly to my laptop just to make sure the problem was not with the ethernet port on my desktop and I had the same result.

 

I am kind of out of ideas at this point but willing to take suggestions and thanks for any and all replies in advance.

Expert

Re: Seriously slow download speeds for 9 days now

The downstream power is on the low side and it may be intermittently fluctuating even lower to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

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.



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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New Poster

Re: Seriously slow download speeds for 9 days now

@EG 

 

Thanks for the reply and I only have one splitter in my apartment and it is the one that was supplied to me by Comcast. Here is more info about it:

 

 

Product Classification  
Brand   HomeConnect®  / Commscope  (Model SV2G)
Product Type   Coaxial splitter
   
Environmental Specifications  
Operating Temperature   -40 °C to +60 °C (-40 °F to +140 °F)
Safety Standard   CE   |   EN 60728-4   |   SCTE
   
Electrical Specifications Isolation  
Isolation at Frequency Band, tap to output, typical   30.0 dB @ 300–1002 MHz   |   35.0 dB @ 5–15 MHz   |   35.0 dB @ 50–300 MHz   |   40.0 dB @ 15–45 MHz
   
Electrical Specifications  
Power Passing   No
Impedance   75 ohm
Operating Frequency Band   5 – 1002 MHz
Insertion Loss at Frequency Band, typical   3.5 dB @ 5–550 MHz   |   4.0 dB @ 550–1002 MHz
Frequency Response   ±0.3 dB
Return Loss at Frequency Band, input, typical   22 dB @ 50–1002 MHz   |   25 dB @ 5–45 MHz
Return Loss at Frequency Band, output, typical   22 dB @ 50–1002 MHz   |   25 dB @ 5–45 MHz
Spurious Signals/2nd Order Harmonics, before surge   <-60 dBc
Shielding Effectiveness, minimum   120 dB
Surge Capability Test Method   ANSI/SCTE 81   |   Category A3 (6 kV, 200 A, Ring wave)
Surge Capability Waveform   100 kHz ring wave waveform
   
General Specifications  
Device Type   Splitter
Mounting   Horizontal
Video Ports, quantity   2
Application   Indoor   |   Outdoor
   
Packed Dimensions  
Carton Quantity   400
Height   215.90 mm   |   8.50 in
Length   482.60 mm   |   19.00 in
Width   368.30 mm   |   14.50 in
Shipping Weight   20.87 kg   |   46.00 lb
Regulatory Compliance/Certifications
Agency Classification
ISO 9001:2015 Designed, manufactured and/or distributed under this quality management system

 

It is not gold plated or anything like that and seems to have the recommended specs that you said I needed so that part should be fine.  I live in an apartment complex and I cannot even see the outside cable line anywhere so I cannot even check to see if there is any issue there. 

 

As far as taking the splitter apart and cleaning it goes, I do not have the skills or tools required for such a task but I do have a couple of coax couplers laying around that I could use instead of the splitter since I am only using one line on the splitter anyway.

 

I am not sure if it wll make any difference though, but it's worth trying I suppose.

Expert

Re: Seriously slow download speeds for 9 days now

Multiple dwellings are particularly troublesome ! That's a good splitter ! If there is nothing that you can do from those tips, then as stated, get a tech out to investigate. Good luck with 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!