Visitor
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5 Messages
Upgrade from Arris TM822R to Arris SBV3202 – Good download improvement but still stuck with 6 Mpbs Upload speed
I have been using Arris TMR822R for years, got an upgrade to 1 Gbps more than a year ago and only decided recently to upgrade to Arris SBV3202 to improve my overall performance.
Performance on Arris TM822R was/is:
Max Download speed 300 Mbps, Upload Speed: 6 Mbps. Please note that I used to get 12 Mbps in upload and only in the last few months I observed that the upload speed had degraded to 6 Mpbs. The upstream parameters of TMR822R showed an upstream power below the acceptable signal level: +51 dBmV to 45 dBmV (see https://arris.secure.force.com/consumers/articles/General_FAQs/TM822G-CT-TM822R-Cable-Signal-Levels/?l=en_US&fs=RelatedArticle)
Upstream
UCID |
Freq |
Power |
Channel Type |
Symbol Rate |
Modulation |
|
Upstream 1 |
78 |
30.10 MHz |
36.50 dBmV |
DOCSIS2.0 (ATDMA) |
5120 kSym/s |
64QAM |
Upstream 2 |
80 |
17.30 MHz |
35.75 dBmV |
DOCSIS2.0 (ATDMA) |
5120 kSym/s |
64QAM |
Upstream 3 |
79 |
23.70 MHz |
35.75 dBmV |
DOCSIS2.0 (ATDMA) |
5120 kSym/s |
64QAM |
Upstream 4 |
77 |
36.50 MHz |
35.50 dBmV |
DOCSIS2.0 (ATDMA) |
5120 kSym/s |
64QAM |
Performance on Arris SBV3202:
Max Download speed 720 Mbps – good improvement but Upload Speed still at 6 Mbps. The upstream parameters of SBV3202 showed an upstream power below the acceptable signal level of +51 dBmV to 45 dBmV as with TM822R (see https://arris.secure.force.com/consumers/articles/General_FAQs/SBV3202-Cable-Signal-Levels)
Upstream
UCID |
Freq |
Power |
Channel Type |
Symbol Rate |
Modulation |
|
Upstream 1 |
78 |
30.10 MHz |
36.50 dBmV |
DOCSIS2.0 (ATDMA) |
5120 kSym/s |
64QAM |
Upstream 2 |
80 |
17.30 MHz |
36.75 dBmV |
DOCSIS2.0 (ATDMA) |
5120 kSym/s |
64QAM |
Upstream 3 |
79 |
23.70 MHz |
35.50 dBmV |
DOCSIS2.0 (ATDMA) |
5120 kSym/s |
64QAM |
Upstream 4 |
77 |
36.50 MHz |
36.00 dBmV |
DOCSIS2.0 (ATDMA) |
5120 kSym/s |
64QAM |
I contacted Arris and they confirmed that the Upstream Power level was not within the expected range.
I did contact Comcast through the chat and asked to check the Upstream power level on their side. The representative was not able to confirm it. Instead I was only given what seems the standard answer: “the modem is unable to handle the speed, I'd suggest you to check with the Original Manufacturer”. Very helpful. There was no change in my house internal connections in the past 2 years so if my upstream signal level went down in the past months, it is more likely due to some work Comcast did in my neighborhood, like for example connecting my new neighbor few months back.
How do we reach technical support Tier 2 at Comcast so I can get real support on this issue?
EG
Expert
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110K Messages
4 years ago
You'll never get the full gig speed or the proper upload speed with that modem as it is only DOCSIS 3.0 compliant. You need a DOCSIS 3.1 capable device.
2
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BruceW
Gold Problem Solver
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26.3K Messages
4 years ago
Using devices on speed tiers for which they are not approved tends to produce unexpected results. Please see https://www.xfinity.com/support/devices/.
0
user_637b33
Visitor
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5 Messages
4 years ago
So let me get this right. I have a modem which according to Comcast is matching the 800 Mbps download speed (as it is rated 940 Mbps by Comcast).
The 800 Mbps speed tier also provides up to 20 Mbps upload speed.
There is nothing wrong with my connection as the Comcast technician that came to my house confirmed my connection was good for up to 42 Mbps upload.
So if I was on the 800n Mbps tier, I would likely get up to 20 Mbps upload. I need to note that I asked Comcast customer service to just downgrade me to the 800 Mbps and charge me the same price for my triple pay plan - I was told they could not do that without also changing my TV plan.
One interesting reddit thread – issue exactly like mine – shows a good example of the replies we get from the Comcast community.
https://www.reddit.com/r/Comcast/comments/mm4qtu/stuck_at_6_mbps_upload_on_gigabit_internet_with/
The most interesting reply however is the following:
“If a customer-owned modem doesn't support the speed, it gets provisioned with a default bootfile. The max speed is about 700/6 on the default bootfile. I ran into this issue with my 16x8 modem when I switched to Extreme Pro and hadn't received my XB7. The only solution is getting a DOCSIS 3.1 modem.” Strange as 700/6 is exactly what my modem provides me today.
I call this behavior “capping”. I can understand that Comcast employees would follow the party line and refuse to agree this is capping. But I do not understand why any non Comcast employee in the Xfinity Community could be fine with this behavior and just repeat the Comcast line: "Get a better modem". This is just capping.
4
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dtrenda
Visitor
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3 Messages
4 years ago
From your tables in the first post, it looks to me like your SBV3202 is tuning only 4 upstream channels. The TM822 is an 8x4 telephony modem, the SBV3202 is a 32x8 telephony modem. So you should have doubled the number of upstream channels being tuned, from 4 to 8. Either the modem is bad and is not tuning more than the original 4 upstream channels, or Comcast has not mapped additional upstream channels to handle the network traffic on the return path towards the local node.
(edited)
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BruceW
Gold Problem Solver
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26.3K Messages
4 years ago
That's not correct. 4 channels is more than enough to deliver the 35 Mbps upstream Gigabit service provides. The problem, as stated above, is that the device is not approved by Comcast for Gigabit service.
(edited)
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EG
Expert
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110K Messages
4 years ago
Comcast currently offers a max of 4 to 5 upstream channels.
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