A Broadband and ADSL forum. BroadbanterBanter

Welcome to BroadbanterBanter.

You are currently viewing as a guest which gives you limited access to view most discussions and other FREE features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload your own photos and access many other special features. Registration is fast, simple and absolutely free so please, join our community today.

Go Back   Home » BroadbanterBanter forum » Newsgroup Discussions » uk.telecom.broadband (UK broadband)
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

uk.telecom.broadband (UK broadband) (uk.telecom.broadband) Discussion of broadband services, technology and equipment as provided in the UK. Discussions of specific services based on ADSL, cable modems or other broadband technology are also on-topic. Advertising is not allowed.

Packet loss seems to have increased, how to diagnose?



 
 
Thread Tools Display Modes
  #1  
Old March 22nd 15, 11:14 AM posted to uk.telecom.broadband
[email protected]
external usenet poster
 
Posts: 83
Default Packet loss seems to have increased, how to diagnose?

My son and I both felt recently that "the internet seemed a bit slow".

I finally took a harder look at things just now and we seem to be
getting rather more packet loss than seems reasonable, typical is this
sort of ping response:-

chris$ ping cheddar.halon.org.uk
PING cheddar.halon.org.uk (217.10.144.130) 56(84) bytes of data.
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=5 ttl=48 time=35.8 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=6 ttl=48 time=33.5 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=7 ttl=48 time=34.6 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=8 ttl=48 time=34.1 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=9 ttl=48 time=33.9 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=10 ttl=48 time=37.3 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=12 ttl=48 time=35.0 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=14 ttl=48 time=34.1 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=15 ttl=48 time=40.3 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=16 ttl=48 time=34.2 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=17 ttl=48 time=35.9 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=18 ttl=48 time=34.4 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=19 ttl=48 time=33.6 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=20 ttl=48 time=34.4 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=21 ttl=48 time=34.6 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=22 ttl=48 time=33.9 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=24 ttl=48 time=35.8 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=25 ttl=48 time=34.6 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=26 ttl=48 time=34.7 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=28 ttl=48 time=34.5 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=29 ttl=48 time=37.8 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=30 ttl=48 time=34.8 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=31 ttl=48 time=33.6 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=32 ttl=48 time=34.2 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=33 ttl=48 time=34.4 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=36 ttl=48 time=33.8 ms
64 bytes from cheddar.halon.org.uk (217.10.144.130): icmp_seq=37 ttl=48 time=35.9 ms
^C
--- cheddar.halon.org.uk ping statistics ---
37 packets transmitted, 27 received, 27% packet loss, time 36095ms
rtt min/avg/max/mdev = 33.593/34.998/40.325/1.477 ms

It seems to take a long time to even start and then loses packets on a
pretty regular basis. I'm sure it used to be better than this.

The ADSL router is a Draytek Vigor 2820n and it's reporting:-

ADSL Information ( ADSL Firmware Version: 232201_A)
TX Cells RX Cells TX CRC errs RX CRC errs
14948715 220326963 1056 27764

Mode State Up Speed Down Speed SNR Margin Loop Att.
G.DMT SHOWTIME 448000 4032000 11 48


So, is my phone line getting noisy or is there something else amiss?

--
Chris Green

  #3  
Old March 23rd 15, 09:47 AM posted to uk.telecom.broadband
Graham J[_2_]
external usenet poster
 
Posts: 723
Default Packet loss seems to have increased, how to diagnose?

wrote:
wrote:
My son and I both felt recently that "the internet seemed a bit slow".

Well a disconnect/reconnect of the 2820n to the phone line seems to
have fixed it. It's renegotiated its speed up a bit too. :-)


Sadly, re-syncing the ADSL modem or rebooting the router will cure a lot
of things, but then you never know why the problem occurred in the first
place.

As regards ping, the first IP address to try would be the Default
Gateway shown in the router. On a 2820n this is called GW IP, in the
WAN1 Status section.

This is the first router in the chain between you and the rest of the
internet, and is generally operated by your ISP. If pinging it is
unreliable then you should take it up with your ISP. However be sure
that you don't have other network traffic using some of the available
bandwidth - this may delay ping responses (by design, ping has a very
low priority). The 2820 will show you a traffic graph to allow you to
identify whether there is any other usage.

If this is reliable, but other addresses (such as
www.bbc.co.uk) are
not, then it's an issue for your ISP. Try several different addresses
from services that likely to have high availability.

Your 11dB SNR margin is not ideal. Having rebooted, what is it now?

If you reboot the router the TX/RX cell count, and TX/RX CRC error
counts should all reset to zero. Note the counts, and work out the
error rate as a proportion of the total packets. Yours look acceptably
low (1 in 10^4 and 1 in 10^5) but beware that all the counters wrap and
I don't know at how many digits). So monitor every few hours.

Also note whether the error counts increase smoothly, or stay fairly
static and increase rapidly on occasion. RouterStats would help here,
but I don't know how to make it work with a 2820. I think I had it
working with a 2800, and certainly with a 2600. Any sudden increase in
error counts would indicate an intermittent noise problem.

If the noise margin increases and the speed consequently decreases your
BRAS profile will reduce, and may take some time to return to its
previously good figure. With some ISPs (BT, Demon) this never happens
and you have to threaten to migrate away to get them to reset it. The
perceived speed will stay slow until the BRAS profile returns to its
former good value. Does your ISP give you a mechanism to see the BRAS
profile?


--
Graham J


  #4  
Old March 23rd 15, 11:27 AM posted to uk.telecom.broadband
[email protected]
external usenet poster
 
Posts: 83
Default Packet loss seems to have increased, how to diagnose?

Graham J wrote:
wrote:
wrote:
My son and I both felt recently that "the internet seemed a bit slow".

Well a disconnect/reconnect of the 2820n to the phone line seems to
have fixed it. It's renegotiated its speed up a bit too. :-)


Sadly, re-syncing the ADSL modem or rebooting the router will cure a lot
of things, but then you never know why the problem occurred in the first
place.

Yes, I know, but still I do at least now have a responsive internet
connection. Next time, if I have the patience, I may try a bit more
diagnosis (if there is a next time of course!).


As regards ping, the first IP address to try would be the Default
Gateway shown in the router. On a 2820n this is called GW IP, in the
WAN1 Status section.

Yes, OK, I did try 'nearby' IPs such as the ISP's DNS. They all
showed the same level of packet loss.


This is the first router in the chain between you and the rest of the
internet, and is generally operated by your ISP. If pinging it is
unreliable then you should take it up with your ISP. However be sure
that you don't have other network traffic using some of the available
bandwidth - this may delay ping responses (by design, ping has a very
low priority). The 2820 will show you a traffic graph to allow you to
identify whether there is any other usage.

If this is reliable, but other addresses (such as
www.bbc.co.uk) are
not, then it's an issue for your ISP. Try several different addresses
from services that likely to have high availability.

It was (I am almost certain) a bad ADSL connection between me and the
ISP, not an issue with ISP connectivity beyond.


Your 11dB SNR margin is not ideal. Having rebooted, what is it now?

It's showing 8 now. I still have the slightly improved speed, it's
4.7Mb/s as opposed to the 4.0Mb/s I was getting before.


If you reboot the router the TX/RX cell count, and TX/RX CRC error
counts should all reset to zero. Note the counts, and work out the
error rate as a proportion of the total packets. Yours look acceptably
low (1 in 10^4 and 1 in 10^5) but beware that all the counters wrap and
I don't know at how many digits). So monitor every few hours.

Dropping the connection and reconnecting has reset the counts. It has
been up just on 24 hours now and I have 1472 receive CRC errors and 35
transmit ones. (RX cells 246749443, packets 735020). I make 1472 in
735020 about 1 in 500 for receive.


If the noise margin increases and the speed consequently decreases your
BRAS profile will reduce, and may take some time to return to its
previously good figure. With some ISPs (BT, Demon) this never happens
and you have to threaten to migrate away to get them to reset it. The
perceived speed will stay slow until the BRAS profile returns to its
former good value. Does your ISP give you a mechanism to see the BRAS
profile?

I'm with PlusNet, they reset it for me some months ago when my speed
had migrated down to 3.3Mb/s or so and wasn't climbing back up. I'm
very happy with 4.7Mb/s, it's as good as I've ever seen from here,
over the years I've usually seen about 4.2 - 4.4Mb/s.

Thanks for all the comments/advice.

--
Chris Green

  #5  
Old March 23rd 15, 12:38 PM posted to uk.telecom.broadband
Martin Brown
external usenet poster
 
Posts: 343
Default Packet loss seems to have increased, how to diagnose?

On 23/03/2015 10:27, wrote:
Graham J wrote:
wrote:
wrote:
My son and I both felt recently that "the internet seemed a bit slow".

Well a disconnect/reconnect of the 2820n to the phone line seems to
have fixed it. It's renegotiated its speed up a bit too. :-)


Sadly, re-syncing the ADSL modem or rebooting the router will cure a lot
of things, but then you never know why the problem occurred in the first
place.


Rebooting the modem is always worth a try before considering any other
more serious sort of fault. Some tend to get unreliable after a month or
two continuous running and/or large throughput.

Yes, I know, but still I do at least now have a responsive internet
connection. Next time, if I have the patience, I may try a bit more
diagnosis (if there is a next time of course!).


Sometimes modems or lines get themselves into strange states where the
statistics report unrealistic values. Several of mine have a habit of
showing a noise margin of zero when they get themselves into trouble.


As regards ping, the first IP address to try would be the Default
Gateway shown in the router. On a 2820n this is called GW IP, in the
WAN1 Status section.

Yes, OK, I did try 'nearby' IPs such as the ISP's DNS. They all
showed the same level of packet loss.


I suspect it is data loss on your ADSL link.

I presume from the ping latency you are on interleaved and some packets
are suffering enough corruption to be unrecoverable.

This is the first router in the chain between you and the rest of the
internet, and is generally operated by your ISP. If pinging it is
unreliable then you should take it up with your ISP. However be sure
that you don't have other network traffic using some of the available
bandwidth - this may delay ping responses (by design, ping has a very
low priority). The 2820 will show you a traffic graph to allow you to
identify whether there is any other usage.

If this is reliable, but other addresses (such as
www.bbc.co.uk) are
not, then it's an issue for your ISP. Try several different addresses
from services that likely to have high availability.

It was (I am almost certain) a bad ADSL connection between me and the
ISP, not an issue with ISP connectivity beyond.


Your 11dB SNR margin is not ideal. Having rebooted, what is it now?

It's showing 8 now. I still have the slightly improved speed, it's
4.7Mb/s as opposed to the 4.0Mb/s I was getting before.


That figures. You can trade noise margin for more speed and if you sync
in the afternoon when MW interference is lowest you get the fastest
connection with a slight risk of degradation after dark.

Conversely you can get a slower more stable connection by syncing well
after dark. Using the diurnal variation in SNR to alter the sync rate.

--
Regards,
Martin Brown
 




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
be packet loss eps uk.telecom.broadband (UK broadband) 1 May 14th 09 02:57 PM
Packet loss with AOL Ian Pollard uk.telecom.broadband (UK broadband) 3 January 20th 07 03:14 PM
NTL & Skype & packet loss. [email protected] uk.telecom.voip (UK VOIP) 8 October 30th 06 10:45 PM
Belkin Pre-N and Packet Loss Pyyrus uk.comp.home-networking (UK home networking) 1 December 17th 05 06:22 AM
Packet loss - 2 weeks now - is it just BT? [email protected] uk.telecom.broadband (UK broadband) 12 October 8th 05 11:39 AM


All times are GMT +1. The time now is 10:35 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.Search Engine Optimization by vBSEO 2.4.0
Copyright 2004-2018 BroadbanterBanter.
The comments are property of their posters.