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[Chrysalis]

is mod 5 hard when not engineer or engineer tools?

I find halving of error rate nothing to be sniffed at.

[les-70]

 Yes it has been a very worthwhile improvement. 

 It was very easy for me as there was a handy earth near the drop wire to internal wire junction box in the loft.  I just added the extra earth connection with a Krone tool.  In other cases it would involve checking whether the unused pair is connected all the way from the master socket to the pole and accessing inside the master socket as well as, if needed, connecting both pairs in  a junction box.   This is also not a legal thing to do as it involves tapering with the BT side, albeit an unused unconnected pair.  I guess Blacksheep would warn even more! I also would guess that it would only help installations via a pole and drop wire.  I tried it as an experiment and will be leaving it, however it can't be recommended. 

[Black Sheep]

Can't hear a word of what you're saying Les, you'll have to speak up !! 

[Chrysalis]

a no go for me then, even engineers shy away from my junction box,  Junction box is up on wall near top of building.

[NewtronStar]

I tried it as an experiment and will be leaving it, however it can't be recommended.

At least you have the balls to give it a try and it won't be to long before you prise open your PCP cab and do a pair swap 

[les-70]

                                  ECI/r modem no longer syncs

   I decided after a break of about 8 weeks to go back the supplied ECI modem to see how, with reduced attainable over that period, it performed relative the HG612.  I have two ECI/r's the supplied one (unmodified) and an unlocked one, both worked 8 weeks ago and the cabinet is an ECI dslam.   Neither would try to sync in the sense of a flashing dsl light.  I returned to the HG612 and got an immediate sync.  I wonder whether it is too do with my speed capping on the HG612, I removed that and the HG612 synced at full speed OK.  I then retried the two ECI/r's but no luck, I left one on the line for 10 mins in case it needed to think on things.     Returning to the HG612 all again it worked fine. 

   I am baffled, I wonder whether either using the HG612 has upset the dslam or my speed capping has done something to it.  When I have time I will open up the unlocked ECI/r and see what the serial output on the uart tells me. 

[les-70]

  On my line with the ECI/r the serial output is just the same with and without the dsl line connected -it simply refuses to connect.   

 I had another four tries, two with an unlocked one and two with the un-tampered engineer supplied one.  I am just moving the cables between the HG612  and ECI/r and since it connects straight away when I return to the HG612 it hard to see that I am doing anything odd.  It seems very odd for a device to be rejected that way.    it is hardly a problem but it is annoying me!!

 I would assume any suitable vdsl modem would achieve a sync and as I said the line has not been capped. With the HG612 it is free to sync at either 80/20 with snr about 7 db and error rates that seem fine but look on the large size or with my usual reduction to 64/16 and a low error rates.  In normal use I can't tell the difference between 80/20 and 64/16 and 64/16 was just intended to keep interleaving at bay. I am surprised that capping would produce this effect.  I am using the unlockedgui-nobtagent firmware in the HG612. 

  Has anyone else with an ECI dslam recently tried to swap an HG612 to an ECi/r?

[JamesK]

Yes, I recently swapped my ECI/r over to the HG612 to get some connection stats on the Mk2 faceplate and the latest HG612 firmware. I left it in place for about a month before swapping back the ECI/r. I connect to an ECI DSLAM and the ECI modem always syncs about 3/4mbps better than the HG612.

I had no issues with swapping them around.

[les-70]

   Mystery solved.     Based on two successful ECI/r connections and two more ECI/r failures the ECI/r seems to be sensitive to which dsl line is A or B.  The twisted pair cable that the Hg612 and HG622 were very happy with has the pairs swapped round one end to the other.  Using a "no swap cable" the ECI/r syncs as it ought to - just fine.  My collection of cables are mostly straight thro but a few are swapped??   I assume the swap is the issue - the only alternative (unlikely I think)  is that swapped cable has a plug that the ECI/r does not like.  i have had things on and off too many times today to want to risk furthers tests.

   Is it a wrong to have a dsl cable which swaps round the pairs??

  Current stats without capping don't show much difference. All with 80/20 sync.

        HG612  038 BLOB  snrm 7.4  attainable 83800
        HG622  033 Blob   snrm 6.7  attainable 85400
        ECI/r                   n/a        attainable 83900   

  I notice that the srnm's don't seem that well related to the attainables between the two HG's. 

[burakkucat]

I assume the swap is the issue -

Eh? Nooo! 

It will be a marginal (or defective) connector on the cable or a marginal (or defective) socket on the CPE and not the "polarity" of the pair.

I could send you off to read Beattie's SINs (for she has many, of course) and all the other standards relating to the xDSL interface to a CPE . . .

[les-70]

   That is what I thought although with less certainty, I was aware the cable had the swap but gave it no significance at all.  I only recalled it when puzzling over why I could not get the ECI/r to sync.  The said cable has always worked with HG's and has always failed on ECI/r.  That is now over about 8 tries on each and with failure free long term use with the HG's.  When the connection has had a chance to forget todays on/off's I will cut a spare cable in half and try it spliced either way round in a more definitive test.

[les-70]

   As B..cat advised I can confirm that the ECI does not care about any swap in the connectors to the dsl line.  My troubles with the ECI are what I thought the improbable alternative.  It is the plug on the dsl cable/ECI socket combination.  The raised plastic ridges on the RJ11 plug that the connector contacts sit in look perhaps marginally narrower in the failed cable than those on the working cables.  It does not worry the HG's or the CPE socket which worked 100% with that cable but the ECI was/is a 100% fail with it.   

[burakkucat]

b*cat dances the "happy dance" . . . 

[NewtronStar]

        HG612  038 BLOB  snrm 7.4  attainable 83800
        HG622  033 Blob   snrm 6.7  attainable 85400
        ECI/r                   n/a        attainable 83900   

  I notice that the srnm's don't seem that well related to the attainables between the two HG's.

Glad the RJ11 cable has been sorted out and until you have the ECI/r unlocked if it were me I would be happy with the HG612 038 BLOB snrm 7.4 attainable 83800 slight decrease in speed for more SNRM thats what I look for these days 

[les-70]

  The HG612 038 BLOB is also my choice.  One of my ECI/r's is unlocked but I am never sure exactly what to make of all stats from it.  edmt does not give an overall snrm value to compare with HG's but the command "btagent_arc_version getstat" includes a single value that may be same thing.  That value is 6.3 which is not so good as the HG's.

 When as I suspect it will, crosstalk takes me below 80/20, it will be worth a further modem comparison to see what is the difference in sync speeds.