Upload Speed unstable with no reason

[Cesco]

Technical question: I just found out that on 3.1 upstream Channel, Power Is just 36. Isn't It low? On 3.0 channels it's 41-42 so it's fine. I have already rebooted by hub4 but found out that upload Speed Is not stable at 50+ as usual, but varies from 20 to 50. Download Speeds, latency and jitter instead are fine.

[gitty]

The power in the OFDMA channel is reported differently, so it's fine. It is power per 1.6 MHz vs power per 6.4 MHz. This is a 4x difference is bandwidth, which means a 6 dB difference in power. When you factor this in, OFDMA is at the same level as your other channels.

[Client62]

On the 3.0 Upstream channels, there should be at least four connected all should be using QAM 64 modulation.

"3.1 upstream Channel, Power Is just 36"

Note the direction of the Upstream Channel, 36 dBmV is the power the Hub is sending to the street cabinet.

The Hub will raise or lower its transmission power level in order to satisfy the signal level required by the street cabinet.

[Cesco]

Thank you both for your kind responses. So this means I should not worry too much for this? But how come that upload speed only Is so unstable and just from today?

[Client62]

Check for a service issue via 0800 561 0061.

The VM network is shared system ( just like a road ) what the folks close to us do can make a difference.
It does not take many folks running endless speed tests during peak times to make the network busy.

[Cesco]

Thanks. That phone number says that there are no issues in my area, but It said the same also two weeks ago when there were a heavy issue and all downstream 3.1 channels were shut off. I will check later in the day in case.

[Cesco]

Okay, issue persists. I am seeing that there is one of the five 3.0 upstream channels that is QAM32 and not QAM64 as it was before. Could it be the issue? Here you can see all my upstream results

[Client62]

Share the full test results from this link...

https://www.samknows.com/realspeed/

Once the test begins click on: Run full test to see all the stats inc Upstream / Jitter / Latency / Packet loss.

The speed at the Hub should reflect your subscription.

[pete_at_home]

Actually both D3.0 & D3.1 channels are shown in the modem per 1.6Mhz of bandwidth, although what your conveying is ok for the purpose of the forum !!

The CMTS adjusts all the channels based on the Total Composite Power received.   OFDMA is lower because it occupies a wider bandwidth, therefore total power is greater & it needs to be lower !!

[gitty]

internally, between the CMTS and the modem, it is per 1.6 MHz for both types of channels, but it is very common for modems to display per channel power (per 6.4 MHz) when displaying the SC-QAM channels (the pre DOCSIS 3.1 way of doing it). By looking at various examples we can conclude that this modem displays per 6.4 MHz.

Edit: I just read your post again...  It does NOT adjust based on total channel power. It adjusts based on power per 1.6 MHz. That means the reported power would be no different if the OFDMA channel was 95 MHz wide (well, depending on the frequency that it uses for ranging).