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Interleaving on line

Aly
Grafter
Posts: 46
Thanks: 5
Registered: 07-08-2013

Interleaving on line

When I first joined Plusnet on the City house gateway I was getting about 16ms to Google now I get:
C:\Users\Alistair>ping google.com
Pinging google.com [173.194.34.66] with 32 bytes of data:
Reply from 173.194.34.66: bytes=32 time=30ms TTL=55
Reply from 173.194.34.66: bytes=32 time=30ms TTL=55
Reply from 173.194.34.66: bytes=32 time=30ms TTL=55
Reply from 173.194.34.66: bytes=32 time=30ms TTL=55
Ping statistics for 173.194.34.66:
   Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
   Minimum = 30ms, Maximum = 30ms, Average = 30ms
I've tried other gateways and it doesn't go below 27ms what has happened? I was really happy but now it is poor for gaming sometimes a yellow conneciton on some games. Speed tests still show 70mb but latency has increased.
12 REPLIES
Mattz0r
Rising Star
Posts: 620
Fixes: 1
Registered: 21-07-2010

Re: Latency through the roof, help please

Hey,
That's not quite "through the roof"
You won't be "though the roof" until you're in the 4 digit numbers Wink
Superuser
Superuser
Posts: 9,577
Thanks: 950
Fixes: 54
Registered: 06-04-2007

Re: Latency through the roof, help please

I imagine the DLM has turned interleaving on, or increased its depth to try to reduce transmission error rates on your line.
David
Plusnet Alumni (retired) orbrey
Plusnet Alumni (retired)
Posts: 10,540
Registered: 18-07-2007

Re: Latency through the roof, help please

Hi Aly,
A 30ms ping certainly shouldn't be causing any issues in games. Any chance you could try a ping to any of the servers you play on, to see if they're much longer?
As regards interleaving I'm afraid this isn't something we can change as it's all fully automated on Fibre but if there are problems affecting the line we'll be happy to do what we can.
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: Latency through the roof, help please

Hi Aly,
Like Matt says, you shouldn't really notice this at all.
To put this into perspective, it takes approximately 300ms to blink your eye, so you really shouldn't be able to tell any difference between 15 and 30ms ping.
SuperZoom
Grafter
Posts: 353
Registered: 17-05-2013

Re: Latency through the roof, help please

You're seriously suggesting that the shortest interval the human eye-brain combination can detect is a blink?    Roll eyes
I think you'll find it's a little more complicated than that. And that context and application matters too. A single frame of standard rate cinema film is 42ms. Add 10ms to that, taking you down to 19fps, and you'll notice.
It's that kind of display of poverty of insight and logic, combined with disdain for customers deemed a priori to have a trifling problem, which gives ISP tech support a bad name.
Your customer is legitimately enquiring as to why latency has doubled for him. Not why it is 30ms. But why it was 16ms and has now doubled.
So you have:
1. It may be interleaving (about which nothing much can be done on FTTC if it is);
2. This shouldn't  be causing an issue (which may or may not be the case, in fact).

Then you have:
3. Is it causing an issue (or, indeed, a sign of something which may begin to cause an issue)? If the customer says it is an issue, then at least take that as the starting point;
4. Can anything be done about it? (It is not impossible, or even unlikely, that a good component of the increase is not last mile but core routing).

Disappointing.
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: Latency through the roof, help please

I think you've misunderstood me! I was trying to put into perspective how tiny and interval it is from 16->30ms.  I certainly wouldn't be able to tell the difference!
I've just tested the line - Interleaving is set to high, which is likely to be as a result of the recent disconnections on the line (see below - 7 in approx 1.5 hours).  As Matt says, we don't have any control over interleaving on Fibre, but there's a chance that once a period of stability is demonstrated it will naturally reduce, thus improving the latency.
<img src="http://community.plus.net/visualradius/generated/image13800230981710.png"/><div style="clear:both;"></div>
Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: Latency through the roof, help please

/*cough
Seven in seven days according to the graph if you include Sunday but if that was when it was installed only 6 since the start
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: Latency through the roof, help please

It was 7 in 90 minutes.  I looked at our RADIUS logs directly.
The graph doesn't show every single drop if there a number within a very small period of time.
SuperZoom
Grafter
Posts: 353
Registered: 17-05-2013

Re: Latency through the roof, help please

Quote from: James
I think you've misunderstood me! I was trying to put into perspective how tiny and interval it is from 16->30ms.  I certainly wouldn't be able to tell the difference!

Nope: I understood perfectly, and you've failed to acknowledge the thinking error. Unless there's something wrong with my maths, 10ms is less than 14ms. But by all means watch your films slowed down if you prefer, or feel free to shun the 60fps revolution. I must say I don't like the hyper-real look myself.
Not seeing the 7 disconnections in 1.5 hours, but agree that stability should lead to less DLM intervention.
I don't think I'll be helping by contributing further, though, as the OP probably didn't envisage a thread about cinema and human reaction/perception times, so time for me to  Lips are sealed  Blink and I'm gone!
Aly
Grafter
Posts: 46
Thanks: 5
Registered: 07-08-2013

Re: Latency through the roof, help please

Thanks everyone for the replies and thanks James for that graph,
All the disconnections have been because I've been trying to get onto a particular gateway, would this trigger the DLM with interleaving?Huh
I'll leave my line alone  Lips are sealed I know through the roof is exaggerated but my latency has doubled what it previously was.
Any previous experience how long it can take for the DLM to reset and turn interleaving off?
Once again cheers for advice a lot more helpful on here than when I was with BE
Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: Latency through the roof, help please

How were you trying to change gateways - resunching the modem or just disconnecting/connecting the router
If the latter it really should affect the DLM
Aly
Grafter
Posts: 46
Thanks: 5
Registered: 07-08-2013

Re: Latency through the roof, help please

Quote from: Oldjim
How were you trying to change gateways - resunching the modem or just disconnecting/connecting the router
If the latter it really should affect the DLM

Yeah was doing it from here