Twisted Pair RJ11 Broadband Modem Performance

Ian

Ian

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As you may have seen in other threads, I've been trying to tackle dwindling performance from my fibre broadband connection. I live about 800m (as the crow flies) from the BTO Cabinet and my cable length may be something like 1.8km - so I'm right on the edge of fibre being worthwhile.

At first, I was getting 21Mbps and that has now dwindled to 18Mbps download.

I've made lots of changes to our internal wiring, added a better filter and pair our existing Router/Modem with the ISP supplied modem which seems to connect with a slightly better SNR.

The last change I've made surprised me. I switch from the supplied flat RJ11 modem cable to a twisted pair RJ11 cable (This one from Amazon). My line attenuation stats went from 27.8dB to 27.0dB and the noise margin improved from 11.8dB to 12.6dB - these aren't huge improvements, but improvements nevertheless. The SNR is already higher than the 6dB it was when I already started making tweaks, but DLM hasn't kicked in to move me to another profile yet. My upload speed did increase from @5000Mbps to 5391Mbps immediately though.

If you're looking to tweak your connection, it may be worth considering - the cables aren't much and if you're handy with crimping tools it will cost next to nothing (you can re-use network cable).
 
Have you looked into a 'filtered faceplate' to replace any/all filters ... you can get a 'proper' BT one or a cheaper somethingorother, both can be had from Amazingdotcon. :)
 
muckshifter said:
Have you looked into a 'filtered faceplate' to replace any/all filters ... you can get a 'proper' BT one or a cheaper somethingorother, both can be had from Amazingdotcon. :)
Click to expand...

Yep, got the MkIII at the moment :). Lots of little improvements here and there, and they're starting to add up :D.
 
Just took a look at the VDSL stats and it looks like I could get closer to 26Mbps once DLM starts loosening off :D:

DS Actual Rate : 17998000 bps
DS Attainable Rate : 26692304 bps
 
Try winding your cables around some Ferrite rings or Core Filters clip on. They only cheap really. Sorta thing you see on cables for power supplies etc

Might make a difference.
I usually strip them out of old PSUs and TVs save buying them
 
I was wondering about Ferrite filters, but wasn't sure if EMI would be a problem on a short 1m shielded cable - I suppose there's no harm in trying one! I've got some clip-on ones I can switch over :).

I've got a power conditioner arriving tomorrow, as it looks like the homeplugs in our house may also operate at the same freq as VDSL - so worth a shot.

I'll update this thread as I make progress - although it may take ages for DLM to pick up the changes.
 
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