Thanks everyone for this thread.
After a year on FTTC; Plus Net notified an upgrade to the Openreach Huawei VDSL modem.
This seemed a good opportunity to try again with the 7390's VDSL modem.
Firmware updated to 84.05.06;
Internet connection via DSL
and the newly available parameter VLAN-ID=101.
Openreach Engineer arrived with modem 22/2/12
- "the old ones had some components that got hot under heavy load and caused sync problems - so Openreach are sending them back to the manufacturer"
He and I tested both the new Huawei modem and the 7390 VDSL modem.
Both synced DSL and both worked OK - so the 7390 was left connected.
The Engineer said " I'm a poles and holes man - this jobs's more comfortable" as he declined coffee and drove off to Edmonton stores for 70 more modems.
The 7390 VDSL modem has now held DSL sync > 100 hours.
Current throughput 39992/10000
Attainable throughput 71928/28945 Kbit/sec between modem and cabinet.
Immediately after the 7390 was connected, thinkbroadband speed test gave 38000/9000, stable over 3 tests.
Next morning, 23/2/12 at 04:50 the exchange forced a disconnection and re-sync.
Since then thinkbroadband speedtest and the 7390 online monitor show an upstream cap at ~4300 Kbit/s.
That's still nice but for the past year it's usually been > 8000.
Plus.Net say "Wait 72 hours" and then suggest using
Download speedachieved during the test was - 35 Mbps
IP Profile for your line is - 38.71 Mbps
Upload speed achieved during the test was - 9.18Mbps
Upstream Rate IP profile on your line is - 10 Mbps
This is roughly the same as the DSL speed as monitored by the 7390
- speedtester.bt would seem to test the link from exchange to modem - not from the ISP backhaul.
Estimated line speed:
Not recorded (service activated before we introduced estimates).
Current line speed:
Not sure what this means?
Either Openreach or Plus.Net have set a cap on the up-link, possibly since the DSL re-sync 18 hours after the modem was swapped.