Re: Hub 3 / Compal CH7465-LG (TG2492LG) and CGNV4 Latency Cause
After waiting what seems like forever, my Virgin Media connection now looks pretty much perfect! The modem updated last night at around 03:30. My graphs are no longer littered with points showing up to 200ms in latency.
My new firmware is 126.96.36.1998
Tests as follows...
IP SLA / Grafana UDP Tests
I have some tests set up from my home router using something called IP SLA, some of which use UDP traffic for tests. Proving that this update isn't just "only fixing ICMP traffic".
It generates test UDP telephony traffic, and sends it off to a server on the internet, which sends timestamped return traffic, and then records the delay for the jitter and latency in each direction. It sends and receives 10 UDP packets mimicking the g729a telephony traffic codec for each test.
Ignore the "One Way Latency" test. Due to the hot weather we're having and my router being in the loft, I'm getting a lot of clock drift as the large swings in temperature affect the clock frequency.
You can see that the UDP round trip time is now very low.
The downstream jitter is now extremely low, with upstream as expected on a cable service.
The MOS test for scoring telephone quality now also looks perfect with the exception of a single blip at 06:30.
ICMP - Ping Plotter, pinging around 50x per second
Ping plotter no longer shows huge spikes every 200ms.
This still looks poor compared to the tests above. This is because my router prioritises traffic passing through it over responding to ICMP traffic. It's not a great indication of how the line is performing. Also, ignore the red blob from yesterday, I caused that.
I'd say well done Virgin Media / Arris but its mental how long this has taken. Virgin Media have handled the fault very poorly.