Visitor

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11 Messages

Thursday, October 23rd, 2025

cm1000 only getting less than 1/2 the download speed my account is rated for

How do I check the firmware version on my modem?

Guy

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Expert

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114.1K Messages

6 hours ago

Which speed plan are you subscribed to ?

Visitor

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11 Messages

it says 600 mbps, best I get is around 250 depending on the time of day

Guy

Expert

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114.1K Messages

6 hours ago

Ok, what do the modem's signal status values look like ? Try getting them here; http://192.168.100.1  


Please copy all of the text in its entirety of the *Downstream Power Levels*, the *SNR's* (Signal to Noise Ratios), and the *Upstream Power Level* numbers and paste them into your next post.

Is there a router in the mix here ? If so, is this with a WiFi connection ?

(edited)

Visitor

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11 Messages

It wants me to log in, I have never logged into this CM1000 it was setup by xfinity

Guy

Visitor

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11 Messages

And yes, there is a router involved, hardwired into the CM1000

these are the speeds directly from the router itself

Guy

Expert

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114.1K Messages

6 hours ago

admin is the default username, and password is the default password.

Visitor

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11 Messages

6 hours ago

Cable Connection
 
Frequency start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Starting Frequency

<tabindex=-1>Startup Procedure</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 495000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enable BPI+
IP Provisioning Mode Honor MDD IPv6 only

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 20 495000000 Hz -5.9 dBmV 43.6 dB 4170228679 55 0
2 Locked QAM256 13 453000000 Hz -5.8 dBmV 43.6 dB 4169219282 31 0
3 Locked QAM256 14 459000000 Hz -5.8 dBmV 43.7 dB 4169229711 39 0
4 Locked QAM256 15 465000000 Hz -5.9 dBmV 43.6 dB 4169227455 26 0
5 Locked QAM256 16 471000000 Hz -5.9 dBmV 43.5 dB 4169237080 28 0
6 Locked QAM256 17 477000000 Hz -5.9 dBmV 43.6 dB 4169241822 35 0
7 Locked QAM256 18 483000000 Hz -5.9 dBmV 43.6 dB 4169240818 26 0
8 Locked QAM256 19 489000000 Hz -5.9 dBmV 43.6 dB 4169245767 37 0
9 Locked QAM256 21 501000000 Hz -5.9 dBmV 43.5 dB 4169246996 32 0
10 Locked QAM256 22 507000000 Hz -5.9 dBmV 43.5 dB 4169268399 36 0
11 Locked QAM256 23 513000000 Hz -6.0 dBmV 43.4 dB 4169279832 34 0
12 Locked QAM256 24 519000000 Hz -6.1 dBmV 43.4 dB 4169282676 39 0
13 Locked QAM256 25 525000000 Hz -6.1 dBmV 43.4 dB 4169283623 50 22
14 Locked QAM256 26 531000000 Hz -6.2 dBmV 43.4 dB 4169274129 67 0
15 Locked QAM256 27 537000000 Hz -6.1 dBmV 43.4 dB 4169268129 72 2
16 Locked QAM256 28 543000000 Hz -6.2 dBmV 43.3 dB 4169305379 48 0
17 Locked QAM256 29 549000000 Hz -6.3 dBmV 43.3 dB 4169289224 36 0
18 Locked QAM256 30 555000000 Hz -6.2 dBmV 43.3 dB 4169293744 33 0
19 Locked QAM256 31 561000000 Hz -6.3 dBmV 43.3 dB 4169280431 26 0
20 Locked QAM256 32 567000000 Hz -6.3 dBmV 43.3 dB 4169298663 26 0
21 Locked QAM256 33 573000000 Hz -6.4 dBmV 43.1 dB 4169317911 24 0
22 Locked QAM256 34 579000000 Hz -6.4 dBmV 43.1 dB 4169308835 49 0
23 Locked QAM256 35 585000000 Hz -6.4 dBmV 43.2 dB 4169295661 38 0
24 Locked QAM256 36 591000000 Hz -6.5 dBmV 43.2 dB 4169300010 25 0
25 Locked QAM256 37 597000000 Hz -6.5 dBmV 42.9 dB 4169325334 24 0
26 Locked QAM256 38 603000000 Hz -6.5 dBmV 43.0 dB 4169326139 21 0
27 Locked QAM256 39 609000000 Hz -6.7 dBmV 42.7 dB 4169336699 31 0
28 Locked QAM256 40 615000000 Hz -6.7 dBmV 42.8 dB 4169328089 31 0
29 Locked QAM256 41 621000000 Hz -6.8 dBmV 42.6 dB 4169323224 28 0
30 Locked QAM256 42 627000000 Hz -6.8 dBmV 42.6 dB 4169343356 27 0
31 Locked QAM256 43 633000000 Hz -6.8 dBmV 42.6 dB 4169349915 47 0
32 Locked QAM256 44 639000000 Hz -6.9 dBmV 42.3 dB 4169342289 45 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 17 16400000 Hz 42.0 dBmV
2 Locked ATDMA 18 22800000 Hz 42.5 dBmV
3 Locked ATDMA 19 29200000 Hz 42.8 dBmV
4 Locked ATDMA 20 35600000 Hz 43.0 dBmV
5 Not Locked Unknown 0 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Hz 0.0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier Number Range Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked 0, 1, 2, 3 193 722000000 Hz -6.2 dBmV 41.0 dB 388 ~ 3707 6546610720 4851502219 0
2 Locked 0, 1, 2, 3 194 957000000 Hz -5.8 dBmV 40.3 dB 148 ~ 3947 6635590530 3678935184 0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked Unknown 0 0 Hz 0 dBmV
2 Not Locked Unknown 0 0 Hz 0 dBmV

Current System Time: Thu Oct 23 13:23:21 2025
System Up Time: 708:13:47
Help Center Show/Hide Help Center

Visitor

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11 Messages

Well that could have come out a little cleaner

Guy

Expert

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114.1K Messages

5 hours ago

This may or may not be the root cause of the problem (YMMV) but it should be addressed regardless. 


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

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/reconfigured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.

Also, check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, or animal chews.

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.

You didn't mention the make and the model number of the router? And for another test, what speed do you get with that PC connected directly to the CM1000 (no router in the mix) ?

You'll need to power cycle the modem when you make this change, and then again when you re-insert the router into the path.

Visitor

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11 Messages

The Router is an ASUS RT-AC66U B1 running the latest firmware

I will start checking the connections, do you have a recommended splitter brand?  I am not sure if there are any, and if they are needed, this modem is the only thing on the line so i may be able to remove any that are in place

Thank you for your help

Guy

Visitor

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11 Messages

No splitters on the line, one FF connector in the closet and a GLS-100 outside in the cabinet, the house is only 6 years old so wiring is all new, connections are tight.

Guy

Expert

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114.1K Messages

5 hours ago

You're quite welcome ! That router should be fine for that speed plan. If it winds up that you need to replace a splitter, I will recommend some brands that Comcast actually uses.

Visitor

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11 Messages

any hints or shortcuts on getting a technician to visit and troubleshoot besides the agonizing phone tree?

Guy

Expert

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114.1K Messages

5 hours ago

Please clarify what a GLS 100 is ? Is it an amplifier ?

Visitor

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11 Messages

it is on the ground block

Guy

Visitor

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11 Messages

Sorry GLF-100 not GLS

Guy

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