VDSL syncing at 40Mbps but only getting 10Mbps speed

[jonathanj]

Hello MyBB!

Firstly, thanks to all the helpful advice posted on these forums, helped prevent a lot of stupid mistakes from happening in the quest for fast Internet!

I'm having a weird issue with my line and I have no idea where to start trying to resolve this.

Bullet points of a long story:

• Got a new line at 4Mbps (that's just what the default was)
• Asked to be upgraded to 20Mbps VDSL and was upgraded to 20Mbps ADSL2+ syncing at ±15Mbps, Speedtest confirmed 15Mbps
• Got a VDSL router (Zyxel VMG1312-B10A) and asked to have a 20Mbps VDSL profile activated
• Syncing at 40Mbps VDSL over PTM, Speedtest confirmed 10Mbps

Various speed test services and file downloads confirms I'm stuck at 10Mbps on the nose. I have a Vox 100GB fatpipe account and an Afrihost 30GB capped account, identical results on each so probably not the ISP. I've also checked my own network to make sure no important hardware has a link speed of 10Mbps.

I'd be really grateful for any suggestions for how to try resolve this.

Pretty sure the router is doing fine (none/very low error count over a long period), but here are the stats anyway:

============================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
            Traffic Type:   PTM Mode
             Link Uptime:   0 day: 19 hours: 40 minutes
============================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:      3.131 Mbps       41.017 Mbps
    Actual Net Data Rate:      3.070 Mbps       40.956 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:       16.1 dB            8.4 dB
            Actual Delay:          0 ms              1 ms
          Transmit Power:        6.9 dBm          14.1 dBm
           Receive Power:       -6.1 dBm          -5.7 dBm
              Actual INP:        0.0 symbols       0.0 symbols
       Total Attenuation:       13.0 dB           19.9 dB
Attainable Net Data Rate:      9.233 Mbps       49.367 Mbps

 

[Cosmically]

You will need to log a fault.

Your profile on Telkom side is most likely (incorrectly) using only 10Mbps cross connect capacity, even though it has synched at 40Mbps.

 

[StillOnSent]

Had the same on a ZyXel twice now
Reboot of Router and all switches on the network fixed it both times (maybe computers on network for good measure aswell)

Seems to be some type of networking bug

 

[LawrenceK]

I have exactly the same modem with exactly the same problem. Yesterday I spent the entire day with Telkom and my line was changed from 40mb to 20mb to 4mb and back to 40mb which its on now and on all occasions except 4mb, I was getting 9.xxmbps..... even with telkoms guest account

Will try the reboot everything route now......

 

[LawrenceK]

Had the same on a ZyXel twice now
Reboot of Router and all switches on the network fixed it both times (maybe computers on network for good measure aswell)

Seems to be some type of networking bug

Thank you. Did the trick. However I took a slightly different route as we have multiple switches in the network and I'm lazy. Unplugged the ethernet from the modem. Powered off and unplugged everything else from the modem. Waited 15sec, pluged only the power and dsl line in. Waited for the modem to boot, then connected with my phone via wifi. did a speed test, All good. Then plugged the ethernet cable back, but into a different port (Originally it was no.1 now it's in no.4) and all the pcs on the network have 37mbps.

On a side note, I have a premium 20mb vdsl sub with my isp, and telkom has now given me a 40mb vdsl line. So somehow it would seem I am getting way above 20mb (37mb in fact).....

 

[tuneme]

Is this connection over wifi or cable? if you are on wifi try connecting using cable and check speedtest