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Arris SB8200 not reaching my Xfinity Plan speeds

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New Poster

Arris SB8200 not reaching my Xfinity Plan speeds

I just upgraded to the Xfinity Gigabit Internet. I have a Arris SB8200 cable modem and tested the connection through ethernet port in the cable modem and my connection is maxing out at 375 Mbps on speed test. I have talked with Xfinity customer service twice and they say everything is fine, but on my end im not seeing the speeds I should be getting. Just a FYI, I also use to have the X1 modem on the 600Mbps plan but wasnt able to get those numbers either.

Event Log

05/28/2020 10:01 84000500 3 "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=c8:63:fc:9f:33:69;CMTS-MAC=00:01:5c:64:cc:66;CM-QOS=1.1;CM-VER=3.1;"
05/28/2020 10:01 67061600 6 "DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=c8:63:fc:9f:33:69;CMTS-MAC=00:01:5c:64:cc:66;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 2436694066 6 "Honoring MDD; IP provisioning mode = IPv6"
01/01/1970 00:01 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=c8:63:fc:9f:33:69;CMTS-MAC=00:01:5c:64:cc:66;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:9f:33:69;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84020200 5 "Lost MDD Timeout;CM-MAC=c8:63:fc:9f:33:69;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:9f:33:69;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84020200 5 "Lost MDD Timeout;CM-MAC=c8:63:fc:9f:33:69;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:9f:33:69;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"

 

Downstream Bonded Channels

Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
8 Locked QAM256 405000000 Hz -0.4 dBmV 39.4 dB 0 0
9 Locked QAM256 411000000 Hz -0.2 dBmV 39.4 dB 0 0
10 Locked QAM256 417000000 Hz -0.2 dBmV 39.3 dB 0 0
11 Locked QAM256 423000000 Hz -0.3 dBmV 38.9 dB 0 0
12 Locked QAM256 429000000 Hz -0.2 dBmV 38.5 dB 0 0
13 Locked QAM256 435000000 Hz -0.4 dBmV 37.9 dB 0 0
14 Locked QAM256 441000000 Hz -0.7 dBmV 37.7 dB 0 0
15 Locked QAM256 447000000 Hz -0.8 dBmV 38.1 dB 0 0
16 Locked QAM256 453000000 Hz -1.0 dBmV 37.4 dB 0 0
17 Locked QAM256 459000000 Hz -0.9 dBmV 37.9 dB 0 0
18 Locked QAM256 465000000 Hz -0.8 dBmV 39.1 dB 0 0
19 Locked QAM256 471000000 Hz -0.6 dBmV 39.3 dB 0 0
20 Locked QAM256 477000000 Hz -0.3 dBmV 39.4 dB 0 0
21 Locked QAM256 483000000 Hz -0.2 dBmV 39.5 dB 0 0
22 Locked QAM256 489000000 Hz -0.3 dBmV 39.3 dB 0 0
23 Locked QAM256 495000000 Hz -0.2 dBmV 39.4 dB 0 0
24 Locked QAM256 501000000 Hz -0.3 dBmV 39.3 dB 0 0
25 Locked QAM256 507000000 Hz -0.2 dBmV 39.5 dB 0 0
26 Locked QAM256 513000000 Hz -0.3 dBmV 39.1 dB 0 0
27 Locked QAM256 519000000 Hz -0.2 dBmV 39.0 dB 0 0
28 Locked QAM256 525000000 Hz -0.2 dBmV 38.7 dB 0 0
29 Locked QAM256 531000000 Hz -0.2 dBmV 38.8 dB 0 0
30 Locked QAM256 537000000 Hz -0.3 dBmV 38.9 dB 0 0
31 Locked QAM256 543000000 Hz -0.3 dBmV 39.0 dB 0 0
32 Locked QAM256 549000000 Hz -0.5 dBmV 39.2 dB 0 0
33 Locked QAM256 555000000 Hz -0.3 dBmV 39.2 dB 0 0
34 Locked QAM256 561000000 Hz -0.2 dBmV 39.3 dB 0 0
35 Locked QAM256 567000000 Hz -0.2 dBmV 39.3 dB 0 0
36 Locked QAM256 573000000 Hz -0.2 dBmV 39.2 dB 0 0
37 Locked QAM256 579000000 Hz -0.4 dBmV 39.3 dB 0 0
38 Locked QAM256 585000000 Hz -0.6 dBmV 39.2 dB 0 0
48 Locked Other 685000000 Hz -2.9 dBmV 36.8 dB 559970269 0


Upstream Bonded Channels

Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 36 Locked SC-QAM Upstream 36700000 Hz 6400000 Hz 49.0 dBmV
2 33 Locked SC-QAM Upstream 17300000 Hz 6400000 Hz 46.0 dBmV
3 34 Locked SC-QAM Upstream 23700000 Hz 6400000 Hz 48.0 dBmV
4 35 Locked SC-QAM Upstream 30300000 Hz 6400000 Hz 49.0 dBmV

 

I would appreciate any assistance in resolving this issue. Thank You!

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New Poster

Re: Arris SB8200 not reaching my Xfinity Plan speeds

Download the Ookla desktop app. You cannot really pull more than 400mbs via Firefox.

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Expert

Re: Arris SB8200 not reaching my Xfinity Plan speeds

FWIW, this may not be the direct cause of your issue, but it should be addressed regardless as it may be another problem just waiting to happen.

 

The upstream power is on the high side and it may be intermittently fluctuating even higher 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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