Big drop in download speed but sync unaffected

[#1]

Hi,

Upgraded from ADSL to Unlimited Fibre (40/10) around 10th August and was happy to get sync of 40/10 and transfers at 37/8.

However I checked yesterday and was disappointed to see that it's now 11.74 down and 8.3 up, but the sync remains at 40...

Latest tests done over Ethernet, with all WiFi disabled, using the test socket.

Think Broadband:

Thu 16/08/2018 22:07 - 36.67 Mbps / 8.23 Mbps - initial FTTC working well
Thu 30/08/2018 11:18 - 11.74 Mbps / 8.30 Mbps - yesterday :-(

 Router stats (Hub One):

6. Data rate:	9999 / 39950
7. Maximum data rate:	19447 / 53389
8. Noise margin:	12.9 / 10.1
9. Line attenuation:	20.2 / 17.3
10. Signal attenuation:	20.1 / 17.3

The PlusNet high speed broadband page:

Estimated line speed:
40Mb (This may vary between 49Mb and 70Mb) - Checked on 2017-11-04 14:11:03
Current line speed:
12.4 Mb

BT Wholesale test:

Download Speed(Mbps): 11.17 Mbps 
Upload Speed(Mbps) : 15.85 Mbps 
Ping Latency(ms): 28 ms 

and then:

1. Best Effort Test: 
Download Speed : 11.17 Mbps
2. Upstream Test: 
Upload Speed : 5.12 Mbps

Your speed test has completed and the results are shown above, however during the test an error occurred while trying to retrieve additional details regarding your service. As a result we are unable to determine if the speed you received during the test is acceptable for your service. Please re-run the test if you require this additional information.

DSL checker:

VDSL Range A (Clean)	70.3	49	20	13.9	40	
VDSL Range B (Impacted)	55.6	35	17.4	9.5	27.4

I spoke to tech support a couple of times and was told:

1: Shouldn't have installed the Hub One on ADSL, before the VDSL was active because hub can get confused about what service it's on. This doesn't seem to have caused a problem as the initial speed tests were good.

2: Shouldn't have turned the hub off for a week when I went on holiday, because the service can decide there's a problem and downgrade speeds. It's been running nearly week now since being switched off.

Thanks

Does this look like a profile/throttling issue or something else?

[#2]

Hi @GeoJ1

Current line speed:
12.4 Mb

 That's not right, given your sync speed, it should be around 38Mb. My guess would be that the current line speed setting has reverted back to your old ADSL value due to a late delta report. However, this setting doesn't restrict the speed for most connections nowadays, unless you have a static IP ?

[#3 · Accepted solution]

Hi @GeoJ1,

I'm sorry that you're experiencing poor speeds at the moment and for any inconvenience that this is causing you.

As you've mentioned, the line is currently syncing at 40mbps down and 10mbps up, and our tests aren't picking up any issues:

GEA Test Detail
Circuit ID	NA	Service ID	BBEUXXXXXXXX

Test Outcome	Pass
Test Outcome Code	GTC_FTTC_SERVICE_0000
Description	GEA service test completed and no fault found .
Main Fault Location	OK
Sync Status	In Sync
Downstream Speed	40.0 Mbps
Upstream Speed	10.0 Mbps
Appointment Required	N
Fault Report Advised	N
NTE Power Status	PowerOn
Voice Line Test Result	Pass
Bridge Tap	Not Detected
Repetitive Electrical Impulse Noise	Not Detected
Estimated Line Length In Metres	541.8
Upstream Rate Assessment	Very Good
Downstream Rate Assessment	Very Good
Interference Pattern	Not Detected
Service Impact	No Impact Observed
Home Wiring Problem	Not Detected
Technology	VDSL
Profile Name	0.128M-40M Downstream, Retransmission Low - 0.128M-10M Upstream, Error Protection Off
Time Stamp	2018-08-30T08:30:00

Parameters	MIN	MAX	AVG
Down Stream Line Rate	39.9 Mbps	39.9 Mbps	39.9 Mbps
Up Stream Line Rate	9.9 Mbps	9.9 Mbps	9.9 Mbps
Up Time	900.0 Sec	900.0 Sec	900.0 Sec
Retrains	0.0	0.0	0.0

Current and Last 15 Minute Bin Performance
Parameters	Last Traffic Count(Upto 15 mins)	Current Traffic Count(Upto 15 mins)
Start Time Stamp	2018-08-30T12:49:19Z	2018-08-30T13:04:19Z
Ingress Code Violation	0	0
Egress Code Violation	0	0
Errored Seconds	0	0
Severely Errored Seconds	0	0
Unavailable Seconds	0	0

However, the connection profile on your account was set lower so I've adjusted this now to try and resolve this issue. Please can you reboot your router and let us know if you continue to experience poor speeds? If so, we'll investigate this further for you.

[#4]

Hi @EmilyD

Thank you, that's a lot better! Now getting: 37.2 / 8.5

Any idea what caused this?

[#5]

Hi @MisterW

Yes I am on a fixed IP. Been with PlusNet a long time.

[#6]

Hi @GeoJ1 

I'm afraid we can't actually give you a solid answer on this one...

Initial testing didn't throw up any indicative reasoning and now things are looking good again, its somewhat difficult to diagnose a fault/issue retrospectively. 

Please do not hesitate to get back in touch with us if you need ever need more assistance. 
 

Thanks,

MoR

[#7]

@GeoJ1

Yes I am on a fixed IP

Any idea what caused this?

Well, ultimately the Current Line speed setting of 12.4Mb caused the big drop in download speed, and @EmilyD resetting it fixed the problem.

As to what caused the current line speed to be set to 12.4Mb well that's the $64,000 question! It's supposed to track changes in the BT profile.

I spoke to tech support a couple of times and was told:

1: Shouldn't have installed the Hub One on ADSL, before the VDSL was active because hub can get confused about what service it's on. This doesn't seem to have caused a problem as the initial speed tests were good.

2: Shouldn't have turned the hub off for a week when I went on holiday, because the service can decide there's a problem and downgrade speeds. It's been running nearly week now since being switched off.

TBH both of those answers are rubbish! Using the Hub One on ADSL prior to the upgrade shouldn't cause any problem. As to turning it off for a week causing the DLM to decide there's a problem Switching on & off repeatedly will cause the DLM to think there's a problem but a single off & then on a week later, No!.

Not having it on for a week shortly after the upgrade, may have delayed the profile change report from ADSL to VDSL speeds but that's purely conjecture...

Just keep an eye on the Current Line speed for a while and check that it doesn't change again.

As I said earlier, Current Line speed is no longer used to control the speed on most connections, only those with static IP's so some of the CSC staff may not consider it as a problem.