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DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)

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DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)

 

Was just wondering if that is ok. Our SB8200 is showing DOCSYS3.1 for the download channel connection (blue LED on the front), while DOCSYS3.0 (and 4 channels only) for the upload speed (green LED on the front). It's working according to the advertised speeds, we get 900+Gbit on download and 42 on upload, so I guess it's ok, was just wondering if somebody knows what there is no DOCSYS3.1 upstream (and potentially better upload speeds for Dropbox etc) yet. 

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Re: DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)


@holunder wrote:

 

Was just wondering if that is ok. Our SB8200 is showing DOCSYS3.1 for the download channel connection (blue LED on the front), while DOCSYS3.0 (and 4 channels only) for the upload speed (green LED on the front). It's working according to the advertised speeds, we get 900+Gbit on download and 42 on upload, so I guess it's ok, was just wondering if somebody knows what there is no DOCSYS3.1 upstream (and potentially better upload speeds for Dropbox etc) yet. 


D3.1 has a limit on upload.

https://www.dslreports.com/faq/15643

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Re: DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)


@holunder wrote:

 

Was just wondering if that is ok. Our SB8200 is showing DOCSYS3.1 for the download channel connection (blue LED on the front), while DOCSYS3.0 (and 4 channels only) for the upload speed (green LED on the front). It's working according to the advertised speeds, we get 900+Gbit on download and 42 on upload, so I guess it's ok, was just wondering if somebody knows what there is no DOCSYS3.1 upstream (and potentially better upload speeds for Dropbox etc) yet. 


Yes it's normal. 35 Mbps is the advertised upload speed with the Gigabit speed tier. With their 20% speed over-provisioning you get over 40 Mbps.

 

Comcast does not yet offer DOCSIS 3.1 on the upload.



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Re: DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)

 

Thank you! Helpful to know that Comcast does not (yet) support upload with DOCSYS 3.0.

 

I am just wondering then why my old Arris SB 6183 (DOCSYS 3.0 only) did only get 30Mbit/s in upload since it is and it should be the same then between the SB6183 and the SB 8200.

 

Just FYI, the SB6183 got 300Mbit/s download while the SB8200 gets 900+Mbit/s download and that should be normal DOCSYS 3.0 vs 3.1 difference. And I guess the download I get is limited to 1Gbit/s because of the computer and SB8200 gigabit ethernet port, so will never see 1.2Gbit/s.

 

 

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Re: DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)


@holunder wrote:

 

Thank you! Helpful to know that Comcast does not (yet) support upload with DOCSYS 3.0.

 

I am just wondering then why my old Arris SB 6183 (DOCSYS 3.0 only) did only get 30Mbit/s in upload since it is and it should be the same then between the SB6183 and the SB 8200.

 

Just FYI, the SB6183 got 300Mbit/s download while the SB8200 gets 900+Mbit/s download and that should be normal DOCSYS 3.0 vs 3.1 difference. And I guess the download I get is limited to 1Gbit/s because of the computer and SB8200 gigabit ethernet port, so will never see 1.2Gbit/s.

 

 


That is odd as with my old Moto (Arris) 6141 I was getting 260Mb down and 42Mb up, and that modem is almost a decade old (8x4). I was acapped at 260Mb as my modem was only 8 channels downstream. You can get a good 20-40Mb per channel on any given cable network so you could easily do the gigabit plan with a docsis 3.0 modem and 32x8. But since I got the docsis 3.1 my modem resets every half hour to ten minutes and my error log is full so 3.1 is not all it's cracked up to be...

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Re: DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)


@FifthE1ement wrote:

  You can get a good 20-40Mb per channel on any given cable network

 

A current single 64 QAM modulated, 6.4MHz-wide, 5.120 MSym/sec upstream channel supports a raw data rate of approximately 30.72 Mbps and a real world throughput of approximately 27 Mbps., not 40.

 

If you were referring to a downstream channel, a current, single 256 QAM modulated, 6.4 MHz wide, 5.120 MSym/sec downstream cable channel supports a raw data rate of approximately 43 Mbps, and a real world throughput of approximately 38.1 Mbps.

 

so you could easily do the gigabit plan with a docsis 3.0 modem and 32x8. 

 

A non DOCSIS 3.0 modem will default to using a DOCSIS 3.0 lower speed tier configuration file. You can never get the gig speed tier with a 3.0 modem even if it is technically capable because Comcast will ONLY deliver gig speed via a DOCSIS 3.1 capable modem (with an OFDM / PLC) downstream channel.


 



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Re: DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)


@EG wrote:

@FifthE1ement wrote:

  You can get a good 20-40Mb per channel on any given cable network

 

A current single 64 QAM modulated, 6.4MHz-wide, 5.120 MSym/sec upstream channel supports a raw data rate of approximately 30.72 Mbps and a real world throughput of approximately 27 Mbps., not 40.

 

If you were referring to a downstream channel, a current, single 256 QAM modulated, 6.4 MHz wide, 5.120 MSym/sec downstream cable channel supports a raw data rate of approximately 43 Mbps, and a real world throughput of approximately 38.1 Mbps.

 

so you could easily do the gigabit plan with a docsis 3.0 modem and 32x8. 

 

A non DOCSIS 3.0 modem will default to using a DOCSIS 3.0 lower speed tier configuration file. You can never get the gig speed tier with a 3.0 modem even if it is technically capable because Comcast will ONLY deliver gig speed via a DOCSIS 3.1 capable modem (with an OFDM / PLC) downstream channel.


 


Not true, as I was hitting 260Mb down which would be 32.5Mb per channel and sometimes I got up to 280Mb. So it's definitely possible, maybe not on all networks and configurations of course.

 

As to point two, that is also not 100% true as there are still some Comcast footprint areas I know of utilizing Docsis 3.0 and offering the gigabit internet via 32x8. I know areas in Pennsylvania and New Jersey to be exact. My cousin has the Arris 6190 on one of these such networks in Penn. He is able to pull 950Mb down as well! So it's possible but Xfinity doesn't like to do it as they don't want customers buying docsis 3.0 Moto 6140 devices and asking why they can't get gigabit speeds. Or place any non 32x8 modem in place of the 6140 so they simply say ONLY docsis 3.1. Also for network congestion the ofdm channel is extremely efficient.

Expert

Re: DOCSYS3.1 download (1Gbit) but DOCSYS 3.0 upload (40Mbit)


@FifthE1ement wrote:

@EG wrote:

@FifthE1ement wrote:

  You can get a good 20-40Mb per channel on any given cable network

 

A current single 64 QAM modulated, 6.4MHz-wide, 5.120 MSym/sec upstream channel supports a raw data rate of approximately 30.72 Mbps and a real world throughput of approximately 27 Mbps., not 40.

 

If you were referring to a downstream channel, a current, single 256 QAM modulated, 6.4 MHz wide, 5.120 MSym/sec downstream cable channel supports a raw data rate of approximately 43 Mbps, and a real world throughput of approximately 38.1 Mbps.

 

so you could easily do the gigabit plan with a docsis 3.0 modem and 32x8. 

 

A non DOCSIS 3.0 modem will default to using a DOCSIS 3.0 lower speed tier configuration file. You can never get the gig speed tier with a 3.0 modem even if it is technically capable because Comcast will ONLY deliver gig speed via a DOCSIS 3.1 capable modem (with an OFDM / PLC) downstream channel.


 


Not true, as I was hitting 260Mb down which would be 32.5Mb per channel and sometimes I got up to 280Mb. So it's definitely possible, maybe not on all networks and configurations of course.

 

Physics and facts are facts, sorry...

 

As to point two, that is also not 100% true as there are still some Comcast footprint areas I know of utilizing Docsis 3.0 and offering the gigabit internet via 32x8. I know areas in Pennsylvania and New Jersey to be exact. My cousin has the Arris 6190 on one of these such networks in Penn. He is able to pull 950Mb down as well! So it's possible but Xfinity doesn't like to do it as they don't want customers buying docsis 3.0 Moto 6140 devices and asking why they can't get gigabit speeds.

 

Or place any non 32x8 modem in place of the 6140 so they simply say ONLY docsis 3.1. Also for network congestion the ofdm channel is extremely efficient.


This is your word..... Got docs ?



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