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Packet loss

AvengerUK
Newbie
Posts: 9
Registered: 18-08-2014

Packet loss

Hi all,
For a while now, I've been getting packet loss - especially in the evenings, and when usage occurs over the connection - I used to "Manage" this by using QoS to limit the usage by streaming etc which would help. 
However it has recently got worse (again) - to where VOIP is unusable due to spiking packet loss. I have previously known about "spiking packet loss" on our line, and have contacted support (previously with BT) and then with plus net and got no where. Now that it's "got worse" I am going to submit another request (although, the fault checker is currently down!) - but thought I'd make a post here.
Line stats:
Modulation : G.Dmt
Annex Mode : Annex A/L
Line State : up
Lan Tx : 77636975
Lan Rx : 44506138
ADSL Tx : 1274135
ADSL Rx : 2211889
CRC Down : 1
CRC Up : 172
FEC Down : 8
FEC Up : 13044
HEC Down : 1101
HEC Up : 1
SNR Up : 23.0
SNR Down : 9.5
Line Attenuation Up : 23.5
Line Attenuation Down : 46.0
Data Rate Up : 448
Data Rate Down : 7616
My router is a Asus DSL-N55U - I do know it has a SNR stability adjust which I havn't tried yet (either + or - X DB) - would this be worth trying?
Cheers.
6 REPLIES
Superuser
Superuser
Posts: 10,464
Thanks: 1,926
Fixes: 19
Registered: 22-08-2007

Re: Packet loss

Hi AvengerUK,
Welcome to the forums.  Please do not use the router's SNRM adjust - this will complicate matters at the moment!  Indeed on your line, it is not likely to make a blind bit of difference!!!!  Cheesy
It looks like your line is running ADSL(1) however I cannot tell if that is over 20CN or 21CN services - can you please look here and see if 21CN is available at your exchange - http://www.kitz.co.uk/adsl/adslchecker.php
For a 46dB line, your synch speed is markedly better than what might be expected for either ADSL or ADSL2/2+ so getting more synch out of the line (lower SNRM) is not likely.
The stats do not report and up time against which to assess the error counts - these do not look to be large, but I( do wonder if this router reports the US and DS figures the wrong way around.  The "US" FEC is comparatively large in relation to the HEC errors for US.
It would be useful to see the results of a BT Wholesale speed test (including further diagnostics) and the "current speed" from the PlusNet portal - see the speed issues thread at the top of this forum for details.

HTH,
Kevin
AvengerUK
Newbie
Posts: 9
Registered: 18-08-2014

Re: Packet loss

Hi & Thanks for the reply.
20CN unfortunately.
Current line speed:
    6 Mb
Download speedachieved during the test was - 5.37 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :7.62 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 6 Mbps
Community Veteran
Posts: 4,783
Thanks: 106
Fixes: 20
Registered: 14-07-2009

Re: Packet loss

Quote from: Townman
Please do not use the router's SNRM adjust - this will complicate matters at the moment! 
For a 46dB line, your synch speed is markedly better than what might be expected for either ADSL or ADSL2/2+ so getting more synch out of the line (lower SNRM) is not likely.

Packet loss and a better synch speed than you ought to achieve would suggest that the SNRM is set too low.  Reading about the Asus DSL-N55U has made me distrust that its 'null' state is what it should be.
Superuser
Superuser
Posts: 10,464
Thanks: 1,926
Fixes: 19
Registered: 22-08-2007

Re: Packet loss

Hi,
I think this needs CRT input to eliminate the possibility of exchange congestion.
Kevin
AvengerUK
Newbie
Posts: 9
Registered: 18-08-2014

Re: Packet loss

Managed to submit a support request so I'll see what they say.
After that (depending on what happens) I'll try the adjust, but only as a last resort Tongue
Acassim
Grafter
Posts: 1,075
Thanks: 1
Registered: 11-06-2007

Re: Packet loss

Morning all,
Just to add to this while you're awaiting an update from the support team, all the VP's at the exchange are set to Amber so this will no doubt be impacting performance during the busier periods and I'm afraid that there are no set dates for this to be rectified by the supplier although they are shown as been in the planning stages so maybe we'll see an update on a fix soon.