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Reduction of Throughput & Jitter during Peak times

deathtrap
Grafter
Posts: 1,063
Thanks: 4
Registered: ‎23-04-2013

Reduction of Throughput & Jitter during Peak times

Hi, Since my FTTC unlimited service was activated back in April this year, I have been seeing a varying degree of Jitter, and a reduction in throughput  mainly on the downstream  but the upstream has been affected also, I have tried swapping gateways, doing so would sometimes give  the normal level of throughput or a higher level, but more often than not it would not cause the jitter to stop  

So i reported this as a fault , the fault has progressed through the system  to the stage of Plusnet wanting to send an Openreach engineer to investigate further due to the test results :
taken from the test results
Test Outcome 	Pass
Test Outcome Code GTC_FTTC_SERVICE_1620
Description Higher than normal crosstalk detected on GEA Service.
Main Fault Location OK
Sync Status In Sync
Downstream Speed 80.0 Mbps
Upstream Speed 20.0 Mbps
Appointment Required N
Fault Target Fix Time
Fault Report Advised N
Profile Name 0.128M-80M Downstream, Interleaving Off - 0.128M-20M Upstream, Interleaving Off

Whilst I'm grateful of the fact that Plusnet are willing to send out BT openreach , that is always reassuring ,
But in this particular case  i think that an engineer unless they are a SFI and carry all the test equipment ie JDSU or EXFO , then they won't find anything, Even an SFI engineer  may not be able to do anything regarding crosstalk , if it is crosstalk and not electrical induction (which is something that they would be very reluctant to do anything about due to costs, and the nature of such issues )
Recently, as of late last week the jitter has improved in that it's not as severe as it has been,and some nights have been jitter free  which is replicated on some of the other thinkbroadband quality meters shown in this forum,
However the throughput issue which tends to be more severe on Sunday and Monday nights,worst is (30mbps )  but sometimes isn't as bad,(speed will drop to around 50-60mbps) with a lot of fluctuation  and some nights there is no issue with throughput at the times that i have tested,
I Have tested throughput in a couple of ways  downloading test files multiple streams to same server (using a dl manager) and speedtests from tbb and speedtest.net as well as the btspeedtest ,
My opinion is that my problem that only happens during peak time typically within a window of 7pm-1am Mon- Sat , Sundays lower throughput and the Jitter can sometimes start earlier so 4pm-1am, t other times of the day the connection seems fine, with no jitter evident and throughput at or very near the max of 75.8mbps (9.2MB/S) downstream and 19.5mbps upstream  via third party ftp , (2.3-4MB/s)
And therefore an issue with the VP at the exchange or a congested link somewhere ,either that or it's a contention issue, and an Openreach engineer visit  would be a wasted resource, and expense to plusnet, as they may well report it was right when tested and raise a charge, why BT Wholesale would expect this to be done prior to them looking at their part of ship i don't know, apart from them being obstructive to ISP's(assuming this is the case )
5 REPLIES
Community Veteran
Posts: 6,824
Thanks: 1
Registered: ‎27-10-2012

Re: Reduction of Throughput & Jitter during Peak times

What's the range of jitter (pings) you are seeing?
It might be worth signing up to get a Samknows Whitebox to monitor your performance.
Community Veteran
Posts: 2,286
Thanks: 109
Fixes: 4
Registered: ‎18-02-2013

Re: Reduction of Throughput & Jitter during Peak times

deathtrap
Grafter
Posts: 1,063
Thanks: 4
Registered: ‎23-04-2013

Re: Reduction of Throughput & Jitter during Peak times

The levels of jitter have varied quite a bit over time, sometimes peaking @ around 30-40ms but usually lower 20-30ms  I measure it using Ping plotter pro,
As for Sam knows ,i thought about that sometime ago, before i moved to FTTC but i do sometimes pass a fair amount of data , and unless they have changed things they back then only wanted  those who where light users, So i decided not to bother
The jitter can be a pain ,if i wanted to do some online gaming , but the lower than usual throughput  concerns me more
Plusnet Help Team
Plusnet Help Team
Posts: 13,536
Thanks: 251
Fixes: 69
Registered: ‎27-04-2007

Re: Reduction of Throughput & Jitter during Peak times

Hi there,

Quote
And therefore an issue with the VP at the exchange or a congested link somewhere ,either that or it's a contention issue, and an Openreach engineer visit  would be a wasted resource

We hear what you're saying, even if there is VP or one at the exchange we would still need to arrange an engineer visit to move things towards that as a matter of course but I'd certainly agree that it's something we need to bear in mind.
In the meantime and as we've detected a possible crosstalk issue I feel it best that we deal with that first so we know exactly where we stand before looking at possibly moving things in that direction
If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team
deathtrap
Grafter
Posts: 1,063
Thanks: 4
Registered: ‎23-04-2013

Re: Reduction of Throughput & Jitter during Peak times

If there is crosstalk it's not service affecting, as the issues that i have brought to your attention are peak time related , yesterday there was no jitter  and throughput wasn't affected at the times that i tested,  and for an engineer to assess if  there is an issue with the VP Why  he would need to visit my home ? and there would be little point in an engineer calling in the daytime when throughput is normal and the connection is working as it should ,an engineer  visit unless it was a SFI. Engineer
It would futile as far as checking my connection goes , as they do not carry the equipment needed to carry out Xdsl related tests  and would not be able to tell if crosstalk was present or not, and if there was/is they would do nothing about it, as far as I'm aware they don't regard it as a fault ,
Why? because then they would be obligated to fix it, And that would cost them dearly  and could  in some cases result them running a separate copper pair  outside of the cable bundle and it's sources of crosstalk to the property affected  from the pcp , and they will never do that ,
My fears are that  an engineer who has no or little knowledge of how Xdsl works will turn up  (like to one who installed my fibre service)  with no test equipment and  make things worse, ie disconnecting the modem possibly triggering dlm, and leaving without getting it reset , leaving me  with a broken connection
This im 99.9% sure isn't related to crosstalk  it is far more likely to be a peak time capacity issue, be it with BT wholesale's VP or it's interconnects to Plusnet or the issue is within plusnet's network or peering