Slow ADSL CQM: Difference between revisions

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[[File:CQM-heavyloss.png|none|frame|Heavy packetloss. Packet loss on an idle line is always bad news...]]
[[File:CQM-heavyloss.png|none|frame|Heavy packetloss. Packet loss on an idle line is always bad news...]]


[[File:CQM-lowloss.png|none|frame|...even if only 1% (one red dot at the top is 1%). An FTTC line with 1-3% loss]]
[[File:CQM-lowloss.png|none|frame|...even if only 1% (one red dot at the top is 1%). A line with 1-3% loss]]


If you suspect you have packet loss, also see:
If you suspect you have packet loss, also see:
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[[File:CQM-speed-change.png|none|frame|line dropped and came back slower and with higher latency]]
[[File:CQM-speed-change.png|none|frame|line dropped and came back slower and with higher latency]]


This FTTC line dropped at 01:50, and came back within a minute or two, however, the speed has dropped (horizontal black line at the top) and also the latency (blue at bottom) has increased. There could be a fault here, but in this case we can clearly see that something has happened. If your line has changed in speed and is shown on the graphs, then diagnostics may find a fault, and the Support Team can help.
This line dropped at 01:50, and came back within a minute or two, however, the speed has dropped (horizontal black line at the top) and also the latency (blue at bottom) has increased. There could be a fault here, but in this case we can clearly see that something has happened. If your line has changed in speed and is shown on the graphs, then diagnostics may find a fault, and the Support Team can help.





Revision as of 14:12, 18 March 2015

Using our CQM graphs can give you a good idea as to what could be causing a line to be slow.

You can take a look at your graph and compare it to the examples below to see if there is a match.

Template:AccessCQM

Lots of traffic on the line

Here is an example of a CQM Graph with lots of upload traffic,

Lots of upload in the morning - a backup without any traffic shaping on the client end. This will make the line slow, but is not a fault

This line is doing a large backup from just before 6am. The dark red horizontal line shows the traffic, during this time there is lots of packet loss (red) and the light blue at the bottom is showing high latency. So, whilst the backup is happening the line has about 50% packet loss and around 300ms of latency. Using the line for things like web browsing at this time will be slow and sluggish. However, this is not a fault per-se. It is normal for a line to appear slow when it's being filled with traffic.

However, this traffic may be unknown, it may not be a backup, but could be a virus or peer-to-peer traffic, or almost anything!

Dealing with Lots of traffic

  1. Try to identify what the traffic is: You can do a Traffic Capture
  2. If it's upload traffic, try unplugging devices on the network until the traffic stops
  3. Contact Support for further help

Packet loss on the line

Packet loss is shown as dripping red from the top on the graph. Here are some examples:

Heavy packetloss. Packet loss on an idle line is always bad news...
...even if only 1% (one red dot at the top is 1%). A line with 1-3% loss

If you suspect you have packet loss, also see:

  • Packet Loss - a page with more (slightly technical) details about packet loss
  • CQM Page - Our general page about graphs with Packet Loss examples

Dealing with Packetloss

  1. Run through the ADSL Checks particularly:
    1. Plug router in to test socket
    2. Check phone line for noise, buzzing/hissing
  2. Run line diagnostic tests
  3. Contact Support

Congestion

If it seems slow in in the evening then it could be congestion somewhere between you and AAISP, or (rarely) within AAISP. A line with congestion may look something like this:

Congestion in the evenings, latency occurs in the evenings, during the day is fine

Dealing with Congestion

  1. Contact Support


Line dropped and speed changed

line dropped and came back slower and with higher latency

This line dropped at 01:50, and came back within a minute or two, however, the speed has dropped (horizontal black line at the top) and also the latency (blue at bottom) has increased. There could be a fault here, but in this case we can clearly see that something has happened. If your line has changed in speed and is shown on the graphs, then diagnostics may find a fault, and the Support Team can help.



What Next?

Go to the next step on Slow ADSL Page.