Your forum username:
Do you already have an account?
Forgot your password?
  • Log in or Sign up


    Welcome to Sky User - The Unofficial Support Forum for everything Sky! - Proudly helping over 65k members.


    Advertisement

    Results 1 to 8 of 8
    Like Tree1Likes
    • 1 Post By Scubbie

    DLM Query

    This is a discussion on DLM Query within the Sky Broadband help forums, part of the Sky Broadband help and support category; The last DLM testing completed on my line on 9 April. Download set at 9.2Mbps and upload at 1.3 Mbps ...

    1. #1
      TerryC's Avatar
      TerryC is offline Sky User Member
      Exchange:
      Broadband ISP: Sky Broadband Unlimited
      Router: Sagem F@ST 2504n
      Sky TV: None
      Join Date
      Jun 2009
      Posts
      32
      Thanks
      2
      Thanked 1 Time in 1 Post

      DLM Query

      The last DLM testing completed on my line on 9 April. Download set at 9.2Mbps and upload at 1.3 Mbps and since then its been consistently around 8.3Mbps down and 1.1Mbps up. However the last 4 nights at around 2.15 am it has been re-syncing at various up/down speed combinations initially going to 7.4Mbps/1.1Mbps and now at 8.1Mbps/0.79Mbps. Am I right in thinking something has triggered DLM again or could this be just a routine i.e. periodical (if they do such a thing) DLM run? There is no indication of a DLM test on my Sky homepage. Stats below, I'm about 3.5 km from local switch so I think the the last 9.2Mbps DLM setting was very optimistic. (The D/S noise margin varies between 1.9 and 3.3) and it doesn't drop the connection when it gets low.

      Many thanks


      Broadband Link Downstream Upstream
      Connection Speed 8188 kbps 798 kbps
      Line Attenuation 49.0 dB 29.8 dB
      Noise Margin 2.0 dB 15.15 dB


    2. Advertisement
    3. #2
      Scubbie's Avatar
      Scubbie is offline Sky User Moderator
      Exchange: 02392
      Broadband ISP: Sky Fibre Unlimited
      Router: Sky Q Hub ER110
      Sky TV: Sky+HD box
      Join Date
      Mar 2010
      Location
      Near Portsmouth
      Posts
      27,908
      Thanks
      812
      Thanked 2,195 Times in 2,065 Posts

      Re: DLM Query

      Initially my first thoughts are that your line has developed a fault.

      I would look at checking out all your connections first. Perform a quiet line test with a corded phone in the Master Socket. Ensure that you are not using the router on an extension lead and swap the filter if you are using a microfilter.

      Sky Fibre Unlimited Pro: Connected at 80,000 kbps / 20,000 kbps
      Previous ADSL2+ Speed 19999 kbps 1153 kbps, Line Attenuation 17.5 db 6.9 db, Noise Margin 7.5 dB 8.7 dB
      Speedtest: 17.15MB/s 0.97Mb/s Ping 31 ms

    4. #3
      TerryC's Avatar
      TerryC is offline Sky User Member
      Exchange:
      Broadband ISP: Sky Broadband Unlimited
      Router: Sagem F@ST 2504n
      Sky TV: None
      Join Date
      Jun 2009
      Posts
      32
      Thanks
      2
      Thanked 1 Time in 1 Post

      Re: DLM Query

      Scubbie - thanks for your reply. That was my thought but the line is very quiet and the router is plugged in the filtered mastered socket. It didn't re-sync last night so I'll see what happens over the next few days again. When it says DLM testing completed etc. on "My Sky" do I take it that it does regular checks anyway or is it only if high error counts for example trigger a period of testing?

    5. #4
      Scubbie's Avatar
      Scubbie is offline Sky User Moderator
      Exchange: 02392
      Broadband ISP: Sky Fibre Unlimited
      Router: Sky Q Hub ER110
      Sky TV: Sky+HD box
      Join Date
      Mar 2010
      Location
      Near Portsmouth
      Posts
      27,908
      Thanks
      812
      Thanked 2,195 Times in 2,065 Posts

      Re: DLM Query

      There are a few states for the DLM software that we may be interested in:


      1. Initial training period
      2. Continuous monitoring
      3. Periodical re-profiles due to potential issues


      The initial training period is what everyone is advised of in their introductory letter. This typically starts after 3-4 days and runs for up to 10 days afterwards. However it can be shorter or longer.

      If required, this Initial Training can be triggered by Sky's support staff later on.

      The DLM software runs on the LLU kit in the exchange. It runs all the time to see how good your line is and to pick up any potential errors which may develop. Powering on/off your router a lot will trigger it to re-profile your line as it will consider this as a line fault.

      As the lines are constantly monitored, DLM can and does check it periodically. If you have a temporary problem it appears to be much better at getting it back to where it should be now.

      With the recent updates too, it appears that the DLM software is going around rechecking everyone's lines and many are reporting improved speeds.
      gymno likes this.

      Sky Fibre Unlimited Pro: Connected at 80,000 kbps / 20,000 kbps
      Previous ADSL2+ Speed 19999 kbps 1153 kbps, Line Attenuation 17.5 db 6.9 db, Noise Margin 7.5 dB 8.7 dB
      Speedtest: 17.15MB/s 0.97Mb/s Ping 31 ms

    6. The Following User Says Thank You to Scubbie For This Useful Post:

      TerryC (09-08-13)

    7. #5
      RamboRab's Avatar
      RamboRab is offline Sky User Member
      Exchange: Central (Glasgow)
      Broadband ISP: Sky Broadband Unlimited
      Router: Sky Hub SR101
      Sky TV: Sky+HD box
      Join Date
      Jul 2011
      Posts
      41
      Thanks
      0
      Thanked 0 Times in 0 Posts

      Re: DLM Query

      I've noticed this too over the last few days.

      My MySky account says that DLM last ran 1 month ago.

      My connection now syncs at a target noise margin of 3db instead of 6db.

      My connection has increased from 16Mbps to 19Mbps but it seems that the throughput is much less. Sometimes as low as 10Mbps.

      DLM should have completed by now so I'm not sure what's going on.

    8. #6
      Scubbie's Avatar
      Scubbie is offline Sky User Moderator
      Exchange: 02392
      Broadband ISP: Sky Fibre Unlimited
      Router: Sky Q Hub ER110
      Sky TV: Sky+HD box
      Join Date
      Mar 2010
      Location
      Near Portsmouth
      Posts
      27,908
      Thanks
      812
      Thanked 2,195 Times in 2,065 Posts

      Re: DLM Query

      If DLM is re-profiling your connection, you will notice that the WAN Uptime reset around 2am-3am, in most cases. It can reset any time from 1am-6am though.

      As for the throughput, how are you connected (WiFi or Ethernet)? Also is this one particular site or multiple? Sadly a lot of sites are not geared up to the faster speed we have now.

      Sky Fibre Unlimited Pro: Connected at 80,000 kbps / 20,000 kbps
      Previous ADSL2+ Speed 19999 kbps 1153 kbps, Line Attenuation 17.5 db 6.9 db, Noise Margin 7.5 dB 8.7 dB
      Speedtest: 17.15MB/s 0.97Mb/s Ping 31 ms

    9. #7
      TerryC's Avatar
      TerryC is offline Sky User Member
      Exchange:
      Broadband ISP: Sky Broadband Unlimited
      Router: Sagem F@ST 2504n
      Sky TV: None
      Join Date
      Jun 2009
      Posts
      32
      Thanks
      2
      Thanked 1 Time in 1 Post

      Re: DLM Query

      Scubbie - thanks for the comprehensive and helpful reply. It re synced again this morning at 2.07 am this time at a slightly slower downstream of 8003 Kbps but with an increased d/s noise margin at 5.9 although this varies slightly. I'll give it a few days and see what happens, it's not causing a problem - throughput is 7 Mbs - just intrigued to know what's happening.

      Thanks again.

    10. #8
      Scubbie's Avatar
      Scubbie is offline Sky User Moderator
      Exchange: 02392
      Broadband ISP: Sky Fibre Unlimited
      Router: Sky Q Hub ER110
      Sky TV: Sky+HD box
      Join Date
      Mar 2010
      Location
      Near Portsmouth
      Posts
      27,908
      Thanks
      812
      Thanked 2,195 Times in 2,065 Posts

      Re: DLM Query

      No problem.

      We have noticed on this forum that often DLM will reduce the Noise Margin on the downstream side to around 3dB, decide that there are a few too many errors, then raise it to around 6dB. This may be what has happened with your connection.

      The actual Noise Margin does vary during the day. Various things can influence it, including the position of the sun.

      Sky Fibre Unlimited Pro: Connected at 80,000 kbps / 20,000 kbps
      Previous ADSL2+ Speed 19999 kbps 1153 kbps, Line Attenuation 17.5 db 6.9 db, Noise Margin 7.5 dB 8.7 dB
      Speedtest: 17.15MB/s 0.97Mb/s Ping 31 ms

     

     

    Tags for this Thread

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •  
    SkyUser - Copyright © 2006-2017. SatDish and NewsreadeR | SkyUser is in no way affiliated with Sky Broadband / BSkyB
    RIPA NOTICE: NO CONSENT IS GIVEN FOR INTERCEPTION OF PAGE TRANSMISSION