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Seeing a fraction of total bandwidth since switching to from 120mbps down to 400mbps down (Blast400)

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Seeing a fraction of total bandwidth since switching to from 120mbps down to 400mbps down (Blast400)

<Edited>I'm hoping someone with more expertise here can help in with any pointers.

 

Other than an issue with signal degredation due to a bad splitter, I haven't had many issues with comcast service at my home. We had 120mbps down via a self-owned Arris SB6190 modem (DOCIS 3.0), and routinely saw 90-110% of capacity. 

 

About a month ago, I upgraded to 400 mbps down. Biggest mistake.

 

Since then, I rarely see over 100mbps down... normally somewhere in the 45-70mbps range. Downstream improved from 6-8mbps to 10-12mbps, inline with expectations via the upgraded plan.

 

I ran off all the relevant stats (SNR, Power, and Frequency) from my own modem, and everything looked inline with optimal ranges. However, they blamed my modem, and said DOCIS 3.1 is required for any service above 250mbps. That doesn't align with my research... but ok. They comped me their wireless gateway (which I've tried as a wireless gateway and in bridgemode to my Amplifi mesh router), and nothing has improved. All stats remain similar to the readings from my modem. 

 

<Edited> they sent out a "network tech" that literally tightened connections, replaced CAT6 (which I already did), and checked the drop for chew marks. He left saying that was all he could do. Also left my junction box wide open and lost the clamp to close it... but that is just me venting because I'm that sick of Comcast.

 

I'm checking with Wave and ATT because I'm dying to break contract before my 30-day out (coming up in about a week), but it doesn't sound like they have the type of plans I want/need. I'm fairly savvy with this stuff, so if someone can point me in the right direction, I'll pull at any threads I can. But right now, I'm stuck with terrible service, not many options, and I don't know where to go next. I'm done banging my head against the wall with comcast support.

 

Help.

 

Current modem readouts from the comcast gateway in bridge mode, below:

 

Downstream
Channel Bonding Value
Index
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
48
 
Lock Status
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Frequency
453 MHz
459 MHz
465 MHz
471 MHz
477 MHz
483 MHz
489 MHz
495 MHz
507 MHz
513 MHz
519 MHz
525 MHz
531 MHz
543 MHz
549 MHz
555 MHz
561 MHz
567 MHz
573 MHz
579 MHz
585 MHz
591 MHz
597 MHz
603 MHz
609 MHz
615 MHz
621 MHz
627 MHz
633 MHz
639 MHz
645 MHz
688 MHz
617600000
SNR
39.8 dB
39.9 dB
39.9 dB
39.9 dB
39.8 dB
39.9 dB
39.9 dB
39.8 dB
39.8 dB
39.8 dB
39.7 dB
39.7 dB
39.7 dB
39.6 dB
39.6 dB
39.4 dB
39.4 dB
39.4 dB
39.4 dB
39.2 dB
39.2 dB
39.1 dB
39.1 dB
39.2 dB
39.1 dB
39.0 dB
38.9 dB
39.0 dB
38.9 dB
38.9 dB
38.9 dB
14.7 dB
NA
Power Level
-2.1 dBmV
-2.1 dBmV
-2.1 dBmV
-2.0 dBmV
-2.1 dBmV
-2.0 dBmV
-2.1 dBmV
-2.0 dBmV
-1.9 dBmV
-2.1 dBmV
-2.2 dBmV
-2.1 dBmV
-2.0 dBmV
-2.3 dBmV
-2.4 dBmV
-2.4 dBmV
-2.4 dBmV
-2.5 dBmV
-2.6 dBmV
-2.5 dBmV
-2.6 dBmV
-2.6 dBmV
-2.5 dBmV
-2.3 dBmV
-2.4 dBmV
-2.5 dBmV
-2.5 dBmV
-2.6 dBmV
-2.6 dBmV
-2.5 dBmV
-2.4 dBmV
-1.4 dBmV
NA
Modulation
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM
OFDM
OFDM

 

Upstream
Channel Bonding Value
Index
1
2
3
4
Lock Status
Locked
Locked
Locked
Locked
Frequency
17 MHz
23 MHz
30 MHz
36 MHz
Symbol Rate
5120
5120
5120
5120
Power Level
49.3 dBmV
48.8 dBmV
48.8 dBmV
49.8 dBmV
Modulation
QAM
QAM
QAM
QAM
Channel Type
ATDMA
ATDMA
ATDMA
ATDMA

 

CM Error Codewords
Index
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Unerrored Codewords
1398535795
453312970
453317718
453324393
453331314
453335922
453341610
453348604
453430203
453437538
453441801
453447063
453453533
453458142
453466128
453471133
453584071
453590538
453594938
453600434
453606266
453612826
453618802
453623006
453630427
436508856
453642941
453647869
453653315
453655935
453658776
1398535795
Correctable Codewords
5691
789
897
859
780
836
637
777
718
763
691
773
845
690
586
676
665
608
568
493
453
420
561
526
375
376
391
373
405
419
400
5691
Uncorrectable Codewords
0
1789
1766
1751
1642
1598
1567
1561
1518
1360
1409
1200
1243
1219
1222
1144
1179
1190
1203
1171
1208
1105
1087
1146
1156
1093
1099
1106
1050
1032
1047
0