Sudden speed drop after router lost connection.

Hi,

I got up this morning to find the router was not connected to the internet i rebooted and it looked to be working fine however we were streaming catch up TV earlier and my PC was realy slow i ran a speed test over Ethernet and got this result, i also tested with my phone and got a similar result using Wi-fi i have checked the modem settings and the link rate is showing 9996/8226 (my link rate used to be 39999 and 9995 Kbps) could someone explain what is likely to be causing this.
Thanks in advance.

Speed test - https://eigde79682.i.lithium.com/t5/image/serverpage...

Edited by deleted (Fri 12-Jan-18 18:58:43)

Shortly after posting the above i lost connection again all lights were on but the Broadband light was flashing and the internet light would not come on, after half an hour it connected but my link rate is showing still 9996/8226 not 39999/9995 Kbps like it used to be.

New speed test -
https://www.thinkbroadband.com/_assets/speedtest/but...

Do you have clear dialling tone on the phone line ?

In reply to a post by Zarjaz:

Do you have clear dialling tone on the phone line ?

Just checked and there is a small amount of crackling when listening to the dial tone.

Last night my link speed was 9996/8226 Kbps and earlier it was the same, i have been on to TT support (online chat) and it looks like they have done something as it was showing up for 14 hours earlier and now the link speed is showing back to normal (see below) but my speeds are still poor.


DSL Type: VDSL
Cable Status: Connected
Link Rate: 9998/39999 Kbps
Connection Type: Dynamic IP
Network Status: Connected
Connection Uptime: 0 Day 0 Hour 56 Min 52 Sec

I recently had a line fault on our Zen/Openreach FTTC line.

In the windy weather after Christmas our broadband ( which is normally 70/20 with a SNR below 2 and very reliable ) kept dropping and re-connecting. Sometimes slower and sometimes closer to 70/20.

On the voice line ( both voice and broadband are with Zen ) there was audible noise and I logged a voice fault. Although it took two Openreach engineer visits to find and fix two bad joints the voice circuit is now noise free and the broadband connection stable.

Currently the broadband is stable with a sync rate is 56/20 with a max attainable of 64/20 and a SNR of 6.2. It's been like that since the second engineer visit on Wednesday.

We're now waiting for the DLM to do its thing. In particular the Interleave depth is 1105 and it's normally much lower. Prior to the second engineer visit we were getting 120,00 FEC errors downstream per hours and 99,000 upstream FEC errors. We're now getting 117 and 15 respectively. Looking at the logging data in detail when the Interleaving went up from 8 to 1100 the ping time to Google's DNS servers went from 8ms to 16ms.

Here's hoping DLM kicks in soon!

Looks like DLM can take a fair few days to kick back in. The Zen article says SLM will wait 9 days and can, if there are multiple periods of instability, wait up to 64 days. I'm guessing that because we logged a voice fault the DLM profile won't be manually reset and we need to wait for the DLM to collect stats to reprofile our line.

Zen DLM Information

Several line tests later i now have my own service centre case manager who is going to call me.

My line stats are back to 9998/39999 Kbps but my speed is still poor at 8.99 Kbps down and 9.45 Kbps up so fingers crossed it will be sorted soon.

The noise on the phone line has now gone.

Is it likely that all these disconnects have caused DLM to kick in and if so how long normally does it take for speeds to start to increase?

.

If DLM was the problem then your sync speed would not be 39999

If throughput is still low after sync has improved it suggests that ISP was using IP Profile as some rate limiter or input into a QoS algorithm and they've not seen the increase in the setting (common with PlusNet)

We had a DLM resync while I was out and we're now at 69/20 with an SNR of 5.2 and an Interleave depth of 8 which is nice.

I guess now we have wait a little longer for the SNR target to be dropped from 5.2 to about 2.

If DLM was the problem then your sync speed would not be 39999

If throughput is still low after sync has improved it suggests that ISP was using IP Profile as some rate limiter or input into a QoS algorithm and they've not seen the increase in the setting (common with PlusNet)

Thanks,

If this is the case why didn't support worker i was on the phone to for over an hour pick this up, will the service centre case manager who has been assigned to my case be more likely to notice this and sort out my problem where the other guy didn't?


speed test -
https://www.thinkbroadband.com/_assets/speedtest/but...

Edited by deleted (Sat 13-Jan-18 13:57:17)

This is getting really annoying just lost connection for a few second is this likely to be them doing something or a fault that is causing the problem.


DSL Type: VDSL

Cable Status: Connected

Link Rate: 9998/39999 Kbps

Connection Type: Dynamic IP

Network Status: Connected

Connection Uptime: 0 Day 0 Hour 1 Min 17 Sec

I reckon you�ve an intermittent fault, hence the crackle ....

In reply to a post by Zarjaz:

I reckon you�ve an intermittent fault, hence the crackle ....

The crackle went shortly after they did all the tests and i had to factory reset the router i don't know if that was a coincidence or not.

Is this a high number for a connection time of one hour?

FEC - 8/26003

.

Edited by deleted (Sat 13-Jan-18 15:16:27)

No and FEC are corrected errors

No.

edit: I'm too slow.

Talktalk don't have any IP profile system. Sounds to me like it could be a faulty modem.
Do you have an alternative you could try?

Edited by j0hn83 (Sat 13-Jan-18 15:43:36)

These are my current figures ( DSLstats V6.1 & a HG612) :

Average error rates for 13 Jan 2018

CRC erors per hour: 302 Down, 2.95 Up
FEC erors per hour: 128 Down, 13.2 Up
HEC erors per hour: 0 Down, 0 Up
ES per hour: 0.66 Down, 2.71 Up
SES per hour: 0.66 Down, 0 Up

while last Friday I had

Average error rates for 05 Jan 2018

CRC erors per hour: 2667 Down, 834 Up
FEC erors per hour: 118352 Down, 99288 Up
HEC erors per hour: 26140 Down, 0 Up
ES per hour: 33.7 Down, 195 Up
SES per hour: 5.13 Down, 6.05 Up

In reply to a post by j0hn83:

No.

edit: I'm too slow.

Talktalk don't have any IP profile system. Sounds to me like it could be a faulty modem.
Do you have an alternative you could try?

I have a spare HG633 so i swapped it and it would not connect to the internet (i guess that's why it was in the cupboard) i gave up and connected the original D-link again, checking again and the link speed has dropped from 39999/9995 Kbps down to 9996/7898 Kbps which it was when i first checked this morning.

Speed test -
https://www.thinkbroadband.com/_assets/speedtest/but...

.

In reply to a post by Chippy_Tea_:

In reply to a post by j0hn83:

No.

edit: I'm too slow.

Talktalk don't have any IP profile system. Sounds to me like it could be a faulty modem.
Do you have an alternative you could try?

I have a spare HG633 so i swapped it and it would not connect to the internet (i guess that's why it was in the cupboard) i gave up and connected the original D-link again, checking again and the link speed has dropped from 39999/9995 Kbps down to 9996/7898 Kbps which it was when i first checked this morning.

Speed test -
https://www.thinkbroadband.com/_assets/speedtest/but...

.

Do us a favour and open your own thread i think this may take a while and i could do without extra posts to read that are not answer to my questions, thanks.

Is there noise on the voice circuit now?

We have no internal house wiring - the HG612 and DECT base station are connected to the NTE5C.

For voice noise testing I bought a BT Duet 210 and connected that in place of the DECT base station. I could easily hear noise with the 210 and now that my line has been fixed there's no noise and the broadband is nice and stable.

In reply to a post by bsdnazz:

Is there noise on the voice circuit now?

No its been fine since they did their tests and asked me to reset the router using a paper clip in the hole in the back.

The router cannot be making the crackle you described earlier - the reset hasn�t fixed it, it�s an intermittent fault at present ....

In reply to a post by Chippy_Tea_:

Do us a favour and open your own thread i think this may take a while and i could do without extra posts to read that are not answer to my questions, thanks.

I think you may have misquoted, as I don't think that was intended to be aimed back at yourself or j0hn83.

If I've got that wrong, I apologise and will remove my comment.

(edited to add quote for context)

Edited by jaydub (Sat 13-Jan-18 18:26:09)

In reply to a post by Zarjaz:

The router cannot be making the crackle you described earlier - the reset hasn�t fixed it, it�s an intermittent fault at present ....

You could do this for a living.

It�s worth considering, thanks Tim.

In reply to a post by Zarjaz:

The router cannot be making the crackle you described earlier - the reset hasn�t fixed it, it�s an intermittent fault at present ....

Thanks, i have been checking but will check more often, just checked and there is no noise.

The link rate is back to 9998/39999 Kbps (from 9996/8226) it dropped again yesterday afternoon, i am still only getting 9 Mbps down and up.

Looking at the stats it says the connection time is 12 minutes, i did notice one page didn't load but it was fine after that, can it disconnect and reconnect in a few seconds?

.

Edited by deleted (Sun 14-Jan-18 11:53:20)

In reply to a post by Chippy_Tea_:

In reply to a post by Zarjaz:

Looking at the stats it says the connection time is 12 minutes, i did notice one page didn't load but it was fine after that, can it disconnect and reconnect in a few seconds?

Yes most you do not even notice.

In reply to a post by ukhardy07:

In reply to a post by Chippy_Tea_:

In reply to a post by Zarjaz:

Looking at the stats it says the connection time is 12 minutes, i did notice one page didn't load but it was fine after that, can it disconnect and reconnect in a few seconds?

Yes most you do not even notice.

Thanks it just happened again, one page didn't load then a few seconds l;ate a referesh saw it load again, my line stats have dropped off gain -

DSL Type: VDSL
Cable Status: Connected
Link Rate: 9998/7094 Kbps
Connection Type: Dynamic IP
Network Status: Connected
Connection Uptime: 0 Day 0 Hour 1 Min 3 Sec

My line stats changed at 15:10 while we were all out (what with it being a Monday) and now my connection speed is 72/20 and the SNR margins are 4.3/7.4. I assume this was done automatically by the DLM.

The Interleave depth is 8 and the errors for the day so far are:

Average error rates for 15 Jan 2018

CRC erors per hour: 29.6 Down, 1.55 Up
FEC erors per hour: 483 Down, 7.70 Up
HEC erors per hour: 0 Down, 0 Up
ES per hour: 0.53 Down, 1.39 Up
SES per hour: 0.53 Down, 0 Up

Looks like DLM did its thing again at 10:43 this morning and now the connection speed is 75/20 and the SNR margins are 3.3/7.5 and the interleave depth remains at 8.

The average error rate for the 17th to 18:34 is

Average error rates for 17 Jan 2018

CRC erors per hour: 29.4 Down, 1.72 Up
FEC erors per hour: 625 Down, 10.4 Up
HEC erors per hour: 0 Down, 0 Up
ES per hour: 0.54 Down, 1.51 Up
SES per hour: 0.54 Down, 0 Up

Hi,

I got up this morning to find the router was not connected to the internet i rebooted and it looked to be working fine however we were streaming catch up TV earlier and my PC was realy slow i ran a speed test over Ethernet and got this result, i also tested with my phone and got a similar result using Wi-fi i have checked the modem settings and the link rate is showing 9996/8226 (my link rate used to be 39999 and 9995 Kbps) could someone explain what is likely to be causing this.

Update to problem i had above -


Openreach have been and they changed a very old and badly corroded master socket which was the cause of the problem.

speed test -
https://www.thinkbroadband.com/_assets/speedtest/but...


.

Edited by deleted (Tue 23-Jan-18 16:07:56)

Speeds are now better than they were before i had the problem -

https://www.thinkbroadband.com/_assets/speedtest/but...

.... and has the crackle gone, for sure ?

Not too happy with teh down load graph though - congestion maybe. Can you try again at say 23:00 or midnight and see if it improves.

How long does the DLM take to up the sync to what it should be.?
The reason for the question is that the power was down [switched off by contractors putting in a new boiler & radiators] at that time the DLM knocked 4mbps of off 74mbps.
Today I had smart meters fitted and the power was off for another 30mins and now my sync is 69mbps , so a total of 5mbps lost because of the DLM..

My speeds have always looked like this here is one from October last year -
https://www.thinkbroadband.com/_assets/speedtest/but...

The TT speed test gives me 37 Mbps and Sam knows 35 Mbps i like to use the TBB test as it shows the burst and average speed not the highest as the others do.

Edited by deleted (Thu 25-Jan-18 16:33:14)

That's not how DLM works.
It shouldn't change your sync just because the modem is powered down.

What's more likely is while you have been connected over the previous days other lines on the cabinet have signed up to FTTC.
This causes interference/crosstalk which can reduce your lines potential sync (known as max attainable)
The next time you resync after this it would be at the new lower attainable.

DLM can take action that can reduce your sync, but a modem being turned off once for 30 mins should not cause this.

Some stats from your modem would help.

The older graph is much "nicer" - may not be smooth but much more consistent.

I cannot agree with that , because I do not have a single modem/router my modem is separate from the router [the router is turned off every night] , but the modem stays on.
I have the very first modem that BT/OR issued and up until the first modem disconnect my sync was 74mbps , it is now only 68mbps because if the MODEM looses power for any reason the DLM classes that as a line interrupt and lowers the sync.
I cannot give any modem stats as only the latest combined modem/router can do that.?

I don't need you to agree with me. I'm pointing out how DLM actually works.
VDSL2 is a variable tech. Sync changes. It doesn't mean it's DLM.

because if the MODEM looses power for any reason the DLM classes that as a line interrupt and lowers the sync.

DLM does not artificially lower your sync for a single modem reboot.
DLM uses a system called MTBR (mean time between retrains). In a 24 hour period the Speed DLM profile allows up to 10 line retrains without taking action. Your DLM profile depends on your ISP.

If your original white OpenReach modem is a Huawei HG612 then you can obtain stats from it easily.
If it is an ECI model it is not so easy.

edit: to add to that.... If the modem is down for over 30 minutes DLM doesn't even count it as a resync.

Have a read on how it actually works: http://www.kitz.co.uk/adsl/DLM.htm

Edited by j0hn83 (Thu 25-Jan-18 18:36:49)