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What has happened to my latency?

Community Veteran
Posts: 26,746
Thanks: 959
Fixes: 10
Registered: ‎10-04-2007

What has happened to my latency?

On 20th April, when I last reconnected my latency shot up. You can see it on the attached SamKnows monitoring graph and it also shows up on the Thinkbroadband Quality Monitor:


It has stayed at that level since. I'm on pcl-ag05
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
10 REPLIES
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Community Veteran
Posts: 26,746
Thanks: 959
Fixes: 10
Registered: ‎10-04-2007

Re: What has happened to my latency?

It's not interleaving. From my router:
Downstream
Connection Rate:  8128   Kbps
Line Attenuation: 20     dB
Noise Margin:     10     dB
Max Rate:         9920   Kbps
Interleave CRC:   0
Interleave FEC:   0
Interleave HEC:   0
Fast path CRC:    39
Fast path FEC:    0
Fast path HEC:    0
Superframes:      27034559

Upstream
Connection Rate:  832    Kbps
Line Attenuation: 13     dB
Noise Margin:     13     dB
Max Rate:         n/a
Interleave CRC:   0
Interleave FEC:   0
Interleave HEC:   0
Fast path CRC:    98
Fast path FEC:    0
Fast path HEC:    0
Superframes:      27038099
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
Community Veteran
Posts: 26,746
Thanks: 959
Fixes: 10
Registered: ‎10-04-2007

Re: What has happened to my latency?

Here's a long term SamKnows graph
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
pierre_pierre
Grafter
Posts: 19,757
Registered: ‎30-07-2007

Re: Ofcom and Samknows Broadband Performance Testing

or what happened to mine
Community Veteran
Posts: 1,412
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Registered: ‎29-01-2009

Re: What has happened to my latency?

There's the obvious rise in latency at 11PM, but there is a small drop in the line at 9AM next morning.
My graphs flat-line throughout the period, and are on ptn-ag03. Downstream spec is the same (8128 without interleaving), but vanilla upstream rate at 448.


However, my last re-connection was on the 11th April, when I too saw a shift in latency. Much smaller than yours, but noticeable.

That graph shows a swap from pcl-ag7 to ptn-ag03.
Plusnet Customer
Using FTTC since 2011. Currently on 80/20 Unlimited Fibre Extra.
Community Veteran
Posts: 26,746
Thanks: 959
Fixes: 10
Registered: ‎10-04-2007

Re: What has happened to my latency?

Earlier this evening I tried gateway hopping, rebooting the router etc to see if I could improve things.
Attached graph shows how successful this was!
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
Community Veteran
Posts: 26,746
Thanks: 959
Fixes: 10
Registered: ‎10-04-2007

Re: What has happened to my latency?

Overnight I had no disconnections (I asked Plusnet to check as well) - my router shows WAN has been up since 18:50 yesterday.
So how do you explain this?
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
Community Veteran
Posts: 1,412
Thanks: 4
Registered: ‎29-01-2009

Re: What has happened to my latency?

Maybe we should be running ping/traceroute in the reverse direction - I guess the overall latency depends just as much on the connection that TBB has, and the peering arrangements, as it does on your/PlusNet's connections.
Any idea of the IP that the pings come from?
Plusnet Customer
Using FTTC since 2011. Currently on 80/20 Unlimited Fibre Extra.
MrToast
Grafter
Posts: 550
Registered: ‎31-07-2007

Re: What has happened to my latency?

I've noticed a few things:

  • Pinging the actual gateway gives more variation from ping to ping than pinging something beyond with a short directly peered route eg bbc.co.uk. I put this down to ICMP ping packets being a low priority task for a router and the gateways are busy passing traffic.

  • When on ADSL- Max I had a solid 8-9ms to bbc.co.uk

  • Now I've migrated to ADSL +2 its anything between 12ms and 22ms (consistent ping to ping, variation is day to day). Checking with ping to PlusNet gateway confirms bbc.co.uk is a reliable ping return destination.


NB. My router says 'fastpath' both for ADSL MAx and ADSL +2.
I think that ADSL +2 may not be such a consistent perfomer for latency. Given there is a marginal synch increase in my case (from ~7Mbps to ~8Mbps) I wonder if ADSL-MAX may be better. Can you have upstream un-capped for > 443kbps upstream on MAX?
MrToast
Grafter
Posts: 550
Registered: ‎31-07-2007

Re: What has happened to my latency?

Second thought.......... perhaps its my modem / router rather than anything inherent in ADSL +2?
Community Veteran
Posts: 26,746
Thanks: 959
Fixes: 10
Registered: ‎10-04-2007

Re: What has happened to my latency?

I usually use ntp.plus.net as a target for pings as it takes networks outside Plusnet out of the equation and gives about the shortest route possible excluding the gateway itself.
The latency has stayed at it's normal 12-14ms level since dropping back on Wednesday morning.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)