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Latency Doubled and Speed dropped

jumbo67
Newbie
Posts: 6
Registered: 06-05-2014

Latency Doubled and Speed dropped

I have been on Fibre since 15/5/14.  In this time I've been running at full speed or very close to it, with a nice latency of 20ms.  I'm very happy with the service from plusnet and these speeds/latency had been very consistent and completely rock solid at any time of the day .  That was until today. It seems that at about 4am this morning my line resynced itself to something a good bit lower. (not sure what as I cant see the stats on the modem/router setup).  I did a few BT Speedtests and it seems the IP profile has dropped from 76.2 to 60.9 and the latency to BBC/Google has jumped from 20 to 45!  I'm guessing interleaving has been switched on.
 Would this be the effect of DLM on the line?  It seems odd that one resync would cause such extreme measures or if there was errors on the line that it would be forced to resync so much lower? To be honest its not so much the speed thats the issue but the latency.  The gamers in the household are not happy  Sad
 Is there any chance someone from support could take a look at it for me?  I didn't raise a ticket as I know its not a massive problem but I would just like to get the line back to its full potential if possible.
Many Thanks
David
Here's a TBB graph if its any help.
5 REPLIES
jumbo67
Newbie
Posts: 6
Registered: 06-05-2014

Re: Latency Doubled and Speed dropped

It seems I had another resync in the early hours.  My latency has now dropped down to 24ish.  I'm guessing if interleaving was on that it has now come off again, although my profile still seems to be a good bit lower than before.
Pinging google.co.uk [173.194.41.87] with 32 bytes of data:
Reply from 173.194.41.87: bytes=32 time=25ms TTL=56
Reply from 173.194.41.87: bytes=32 time=24ms TTL=56
Reply from 173.194.41.87: bytes=32 time=24ms TTL=56
Reply from 173.194.41.87: bytes=32 time=25ms TTL=56
Ping statistics for 173.194.41.87:
   Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
   Minimum = 24ms, Maximum = 25ms, Average = 24ms
Plusnet Staff
Plusnet Staff
Posts: 6,346
Thanks: 31
Fixes: 5
Registered: 26-11-2011

Re: Latency Doubled and Speed dropped

Hi David,
I'm sorry to hear that you're having problems with your connection. I've just taken a look at your connection and Interleaving appears to be completely off on your line.
Your connection rate between your BT Openreach Modem and the Fibre Cabinet is:
Downstream Speed: 72.4 Mbps
Upstream Speed:      20.0 Mbps
The line has a few errors on it, I couldn't be sure what's causing this. Have you installed any new electrical items within your house at all that might cause any interference (electrical)? The pings you're getting as of this morning seem reasonable and shouldn't cause the gamers within your household any issues.
Assuming your line remains stable and the errors start to clear up, your speeds will return back to normal. DLM has taken action to try and keep the line stable. If your speeds are much lower than 65Mb at http://speedtest.btwholesale.com with an Ethernet Cable connected, could you try a PPPoE connection ( http://community.plus.net/library/broadband/fibre-help-how-to-set-up-a-pppoe-dialler-in-vistawindows... ) and complete the Fault Checker at http://faults.plus.net?
Chris Pettitt
Cloud Environments Engineer
jumbo67
Newbie
Posts: 6
Registered: 06-05-2014

Re: Latency Doubled and Speed dropped

Hi Chris
    Thanks for the info.  Yes indeed the gamers will be happy  Smiley    I do have a bit of a mess of cables and power adaptors (modem,router,switch and laptop)  in the same area as the modem. I'll try and get that all organised a bit better.  I'll give it a bit of time and see if the speed comes back up again, as I said, I'm not overly worried about that at the minute.
  As a side note, I'm wondering if the fact that the engineer supplied me with a ECI modem and the cabinet is a Huawei makes any difference?  I've ordered a HG612 of Ebay anyway. Although i'll wait until things settle a bit as I'm reluctant to start unplugging stuff and causing resyncs at the minute.
  Also the engineer mentioned that there was 112 lines connected to the cabinet. Is that a lot, or enough to cause crosstalk?  I'm pretty close to the cabinet, I can see it from my window, about 200 meters at a guess.
Thanks for the help.
David
Plusnet Staff
Plusnet Staff
Posts: 6,346
Thanks: 31
Fixes: 5
Registered: 26-11-2011

Re: Latency Doubled and Speed dropped

Hi David,
The make and model of the modem shouldn't cause any issues as they are compatible so that should be fine. Yes, keeping the connection in place for now would be the best option and no doubt the speeds will improve automatically.
112 connections is about half capacity if you have one of the larger cabinets as shown here: http://3.bp.blogspot.com/-IsJV4oaKZic/T6w-Tar18pI/AAAAAAAAbb8/QcpO5hgZIdA/s1600/bt-cab.jpg this type of cabinet can hold up to 288 connections at a time. Crosstalk could be a factor but from the testing that I completed, it didn't flag any potential issues that that effect up.
I've written up up some documentation on FTTC and how it works if you're interested here: http://community.plus.net/library/browsing/fttc-dlm-what-it-is-how-it-works/
Chris Pettitt
Cloud Environments Engineer
jumbo67
Newbie
Posts: 6
Registered: 06-05-2014

Re: Latency Doubled and Speed dropped

Thanks again for the info Chris