Re: 4 upstream channel bonding - post here
 

I am on 2 channels and have no problems uploading at 2.54MB/sec

Re: 4 upstream channel bonding - post here
 

Nor me:

https://www.cableforum.co.uk/images/...2017/08/10.png

I was just curious what speeds 2 channels could actually support in the (VM) real world when the Wikipedia maximum is over 50Mbps

Re: 4 upstream channel bonding - post here
 

it is all depends on the modulation of the upstreams. Some are still QAM16 and some are QAM64. Those that are QAM64 have a 50% increase on throughput vs QAM16

http://www.radio-electronics.com/inf...qam-256qam.php

Re: 4 upstream channel bonding - post here
 

But that additional throughput goes away when you only allow 2 ticks instead of 4 for your transmit window. Nothing else has moved; it's still a 6.4MHz wide channel (as evidenced by the 5120K symbols/sec rate); the tick is still 6.25us.

Or, as Igni has mooted (not in his words though), has Cisco increased simultaneity at the CMTS so as to allow smaller transmit windows and thus allow more users to to get onto the upstream with smaller amounts of data that won't get too much contention at the CMTS. Something like that?

Re: 4 upstream channel bonding - post here
 

they must have done something because they wouldn't have spent all that time trying to get the upstreams up to qam64 if it wasn't going to provide some benefit to them (you know what VM are like).

Re: 4 upstream channel bonding - post here
 

They have the aim of giving at least 10:1. So by cleaning up the upstream components, they can get to 64QAM under DOCSIS 3.0.

And then they reduce the Mini-slot size from 4 to 2. Thinking deeper, and again with an eye to what Igni said, they may be using something more powerful at the Cisco CMTS end by way of FEC correction; like the DOCSIS 3.1 FEC handling regime. Whether or not that sits well with DOCSIS 2 or DOCSIS 3, I don't know. But it is the only thing I can think of that increases upstream efficiency. Igni will no doubt put me right on this.

Re: 4 upstream channel bonding - post here
 

yeah, I just can't wait for docsis 3.1 though. I had a quick read of the wiki article and it is going to be like jumping to warp speed.

Re: 4 upstream channel bonding - post here
 

And all I want is more than 20 up for once.

Re: 4 upstream channel bonding - post here
 

Unfortunately I doubt Virgin will be rolling it out like that, I expect the initial 3.1 trials to use the same kinds of speeds we get now. I expect it'll be some years before we see gigabit downloads and probably a good 5+ years at the least before we see 100Mbit+ upload speeds.

Re: 4 upstream channel bonding - post here
 

They are rolling it out like that, though using 3.0 upload channels for the foreseeable. Still plenty of life in 3.0 as a whole so no rush.

Re: 4 upstream channel bonding - post here
 

We had a power cut yesterday for an hour just after midday but it took til after eight for the boxes to reconnect but now I have 4 upstreams bonded on the SH1 but only at QAM16:

Upstream US-1 US-2 US-3 US-4
Channel Type 2.0 2.0 2.0 2.0
Channel ID 68 65 66 67
Frequency (Hz) 53700000 Hz 45800000 Hz 35800000 Hz 27400000 Hz
Ranging Status Success Success Success Success
Modulation QAM16 QAM16 QAM16 QAM16
Symbol Rate (Sym/sec) 5120000 5120000 5120000 5120000
Mini-Slot Size 128 64 128 128
Power Level (dBmV) 47.0 dBmV 46.0 dBmV 46.8 dBmV 46.8 dBmV
T1 Timeouts 0 0 0 0
T2 Timeouts 0 0 0 0
T3 Timeouts 2 2 2 2
T4 Timeouts 0 0 0 0

Power levels up and down are nicely within spec. :)

Re: 4 upstream channel bonding - post here
 

they are all qam16

Re: 4 upstream channel bonding - post here
 

They've all moved up to QAM64 now. :)

Re: 4 upstream channel bonding - post here
 

I've had four upstream channels for at least seven months now, but they are all still on QAM16

https://www.cableforum.uk/images/local/2018/05/2.png

Re: 4 upstream channel bonding - post here
 

if you get full speed and there aren't any congestion issues them don't worry about it. Moving all 4 channels to qam64 only gives you a 50% bandwidth increase.