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Intermittent Internet Speed Dips

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Intermittent Internet Speed Dips

Hey Xfinity forums,

I'm looking for help as to what I should try next in terms of my issues with internet access. It cuts out at least 2 to 3 times a day and usually a modem restart will get it back up and running. I have only one coaxial splitter inside the house and I have just recently bought a new Modem (SB6183) to try and fix the issue. I have the following Modem status, which seems like the power and SNR are way too low. I'm not sure what to try next. I hear that switching out the splitter could help, but I think there is something else going on since my power is so low.


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


Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Corrected Uncorrectables
1 Locked QAM256 2 471000000 Hz -22.7 dBmV 32.0 dB 5 0
2 Locked unknown 1 465000000 Hz -29.8 dBmV 0.0 dB 0 0
3 Locked unknown 3 477000000 Hz -25.7 dBmV 0.0 dB 0 0
4 Locked unknown 4 483000000 Hz -32.0 dBmV 0.0 dB 0 0
5 Locked unknown 5 489000000 Hz -27.3 dBmV 0.0 dB 65479 325269
6 Locked unknown 6 495000000 Hz -25.8 dBmV 0.0 dB 10540372 6235415
7 Locked unknown 7 507000000 Hz -29.8 dBmV 0.0 dB 0 0
8 Locked QAM256 8 513000000 Hz -26.6 dBmV 28.1 dB 2799569 13
9 Locked unknown 9 519000000 Hz -29.7 dBmV 0.0 dB 0 0
10 Locked unknown 10 525000000 Hz -29.7 dBmV 0.0 dB 63427 323541
11 Locked unknown 11 531000000 Hz -32.3 dBmV 0.0 dB 0 0
12 Locked unknown 21 603000000 Hz -47.3 dBmV 0.0 dB 0 0
13 Locked unknown 27 633000000 Hz -44.8 dBmV 0.0 dB 0 0
14 Locked unknown 28 639000000 Hz -38.9 dBmV 0.0 dB 14349 75467
15 Locked unknown 29 645000000 Hz -36.8 dBmV 0.0 dB 0 0
16 Locked unknown 33 669000000 Hz -51.1 dBmV 0.0 dB 17934 93368



Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 1 5120 Ksym/sec 36800000 Hz 54.0 dBmV
2 Locked ATDMA 3 5120 Ksym/sec 24000000 Hz 54.0 dBmV
3 Locked ATDMA 2 5120 Ksym/sec 30400000 Hz 51.5 dBmV



Any suggestions would be appreciated.



Re: Intermittent Internet Speed Dips

Your connection is terrible. Stats are out of spec ! That can cause random disconnects, spontaneous re-booting of the modem, and speed 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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