Hi, I know this post may take a while to be acknowledged by Virgin Media Staff, however its not an urgent issue currently....
The issue I've noticed over past few weeks is instability in upstream and increases in jitter/latency, looking at modem information shows alot of timeouts on upstream and modulations dropping to 16/32QAM across some or all channels (4)
This is causing intermittent lagging in live streaming and time sensitive applications and also the odd rebuffer on streaming services, along with substantial loss of upstream bandwidth.
Hub reboots often fix the problem but can return quickly.
I run in modem mode and restarting hub can be inconveinient.
EDIT: Adding speed test for illustration.
Would be willing to try new Hub 5 if possible.
UPDATE 5/8/22 @ 17:15 - Reboot didn't resolve issue this time, still stuck at 16QAM for all upstream channels.
Router is a mikrotik ccr1036
As said really, issue is network side, just want someone from Virgin to take a look and possibly get issue resolved before things end up bad, also wondering if there could be changes being implemented as I've seen D3.1 upstreams coming online from other customers and more D3.0 US channels getting added in too.
Yep, that upstream power is rather on the high side. Out of curiosity why are you speedtesting to a French server?
I'm right on top of the cabinet hence high upstream, can't say its been a major issue before but then who knows with the junk chipset in the H4.
As for server testing, OVH in Erith seems to have disappeared for some reason and the ping to OVH even in France is better than the next nearest 10Gb server (Datapacket in London)
I think there is peer congestion with Datapackets server too as it's not giving very good results.
UPDATE: Messaged with someone from support earlier, they told me an issue in area they are working on, though it wasn't showing on Service Status page, I asked for reference and got given SNR/FEC which seems more like a fault code to me and would make sense.
I've since got back to 64QAM and got bandwidth and stability back.
"If the voltage is high they normally put a resistor block on it to get it to drop back into normal range. "
Attenuators are ever affect the downstream signal to lower if if it’s too high. High upstream cannot be lowered in this way as it’s a negative figure and a full band attenuator would old make it worse. High upstream means the hub cannot get an adequate signal to the CMTS. It’s like pushing a truck uphill, the heavier the truck the more force needed, same as upstream power levels. Downstream is the reverse, it’s the signal received from the CMTS, so high is better than low.