Kitz Forum

Broadband Related => Telephony Wiring + Equipment => Topic started by: mdesai on October 26, 2020, 08:37:34 PM

Title: VDSL CAT6 Extension: Confused
Post by: mdesai on October 26, 2020, 08:37:34 PM
Hi

I have after many years move away from Virgin Media. My setup with VM was telephone socket in one room and broadband in another. Openreach installed a new line and they only install to one location where my vm telephone line was. At the front of my house. Whereas my vm broadband outlet was in a bedroom at the rear of my home. I am a novice with Openreach BT sets up. So I don't understand the stats but the wiring is very simple to understand.

So since the install, I decided to run a CAT 6 vdsl extension from the master socket in the front room to rear bedroom externally and via the loft. It's about 45 meter cable (I have left a lot of slack for now. Maybe another 10m will come off once I finalise the install).

All has gone well. I can connect my modem to new extension and get the exact same link speeds as I did at the master socket. However when I now plug the modem directly into the NTE5C MK4 VDSL faceplate. My link speeds drop by 10,000kbps. Which confused me as if anything I should be getting worse speeds through the extension and not the master socket!

In terms of trouble shooting.

I first thought my cat 6 rj45 euro module was faulty so I got a short piece of twisted pair a couple of centimeters and joined it to the AB terminals on the back of the vdsl faceplate and the link speed is the same on both vdsl faceplate and rj45 euro module. I also cimped a RJ12 to some spare twisted pair and then connect that to the AB terminals and got the same speeds at the faceplate socket and the rj12 connected directly.

I don't think it is the actual cat 6 cable as it works fine when plugged into that. However when I disconnect the CAT6 cable from the AB terminals the vdsl faceplate works fine. I also tested the cable using a rj45 continuity tester. Seems fine

I also disconnected the telephone extension running down the same cat 6 cable and no difference.

Just a bit odd that now with the extension the master socket vdsl is not working as well as the extension one.

I have included screenshot of most the scenarios I have tried

Is there something I have missed? It quite ironic as the official advise is you will get the best performance when directly connect the master socket. Not in this case

Also the faceplates meant to be really loose, seems a slight tap or even a breeze will loosen the faceplate. I thought they only come when you pinch both sides.

Any help will be appreciated! :)



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Title: Re: VDSL CAT6 Extension: Confused
Post by: burakkucat on October 26, 2020, 10:54:47 PM
Welcome to the kitz forum.  :)

. . . since the install, I decided to run a CAT 6 vdsl extension from the master socket in the front room to rear bedroom externally and via the loft. It's about 45 meter cable (I have left a lot of slack for now. Maybe another 10m will come off once I finalise the install).

All has gone well. I can connect my modem to new extension and get the exact same link speeds as I did at the master socket. However when I now plug the modem directly into the NTE5C MK4 VDSL faceplate. My link speeds drop by 10,000kbps. Which confused me as if anything I should be getting worse speeds through the extension and not the master socket!

The effect is understandable and I can confirm that there is no fault. As you have extended the data port to the extension socket, the original data socket at the SSFP must not be used. When tested at the SSFP socket, the data extension wiring will appear as a bridging tap across the pair --  with the end result that you have observed.

Quote
Also the faceplates meant to be really loose, seems a slight tap or even a breeze will loosen the faceplate. I thought they only come when you pinch both sides.

Unfortunately the NTE5C + Mk 4 SSFP combination is a poor design. Those of us in the know prefer to use the NTE5/A + Mk 3 SSFP combination.
Title: Re: VDSL CAT6 Extension: Confused
Post by: j0hn on October 27, 2020, 12:24:44 AM
Careful not to resync the line too often testing sync speeds at various sockets.
Every resync counts as instability and too many will see the sync speed capped by the line management system (DLM) which can take months to reverse itself.
Title: Re: VDSL CAT6 Extension: Confused
Post by: Alex Atkin UK on October 27, 2020, 12:43:41 AM
Unfortunately the NTE5C + Mk 4 SSFP combination is a poor design. Those of us in the know prefer to use the NTE5/A + Mk 3 SSFP combination.

I recently replaced my Plusnet line with a NTE5C + MK4 and its a REALLY tight fit.  I just hurt my fingers trying to pull on it, its not going anywhere.

Also it seems a much better fit for RJ11 plugs than the MK3, that socket never seemed very secure.
Title: Re: VDSL CAT6 Extension: Confused
Post by: burakkucat on October 27, 2020, 02:10:47 AM
Also it seems a much better fit for RJ11 plugs than the MK3, that socket never seemed very secure.

All data sockets on any of the SSFPs are actually 8P2C (often incorrectly called "RJ45"). 
Title: Re: VDSL CAT6 Extension: Confused
Post by: Alex Atkin UK on October 27, 2020, 03:57:11 AM
All data sockets on any of the SSFPs are actually 8P2C (often incorrectly called "RJ45").

Is it incorrect to call it RJ45?  RJ45 is the physical plug/socket whereas 8P2C is how its physically wired.

Anyway, it doesn't alter the fact my MK4 fits snugly and my MK3 does not.
Title: Re: VDSL CAT6 Extension: Confused
Post by: tubaman on October 27, 2020, 07:53:58 AM
The effect is understandable and I can confirm that there is no fault. As you have extended the data port to the extension socket, the original data socket at the SSFP must not be used. When tested at the SSFP socket, the data extension wiring will appear as a bridging tap across the pair --  with the end result that you have observed.


This is the exact same thought that came into my head as I read the initial post. For the amount of speed loss sustained the extension cable is clearly just the 'right' length to demonstrate the bridging tap phenomena perfectly.
 :)
Title: Re: VDSL CAT6 Extension: Confused
Post by: siofjofj on October 27, 2020, 10:08:35 AM
The effect is understandable and I can confirm that there is no fault. As you have extended the data port to the extension socket, the original data socket at the SSFP must not be used. When tested at the SSFP socket, the data extension wiring will appear as a bridging tap across the pair --  with the end result that you have observed.
This is the exact same thought that came into my head as I read the initial post. For the amount of speed loss sustained the extension cable is clearly just the 'right' length to demonstrate the bridging tap phenomena perfectly.
All agreed. If I remember correctly, in the early days of VDSL when an Openreach engineer would perform a 'managed install', if the VDSL modem was required to be located away from the master socket the attending engineer would fit a 'data extension kit' which came fitted with an RJ45 plug at one end which connected to the socket on the filter faceplate. The reason for this was to prevent exactly this error being made in the future, since connecting a modem to the master socket would then require the extension to be disconnected. Regardless of this, I personally choose to use the A & B terminals on the back of the faceplate as it is neater.

Also the faceplates meant to be really loose, seems a slight tap or even a breeze will loosen the faceplate. I thought they only come when you pinch both sides.
The quality control on the NTE5C and VDSL Mk4 SSFP combination seems to be quite poor. Some do clip on properly, some fit ridiculously tightly (like Alex Atkin's) and some just come off without touching the clips (like yours and also mine). What you can do to improve this, with the faceplate off, is gently warm the clips that go into the master socket using your hands then gently and repeatedly bend them outwards. I did this to mine and it is now much better and doesn't fall off all the time.
Title: Re: VDSL CAT6 Extension: Confused
Post by: Alex Atkin UK on October 28, 2020, 03:24:42 AM

The quality control on the NTE5C and VDSL Mk4 SSFP combination seems to be quite poor. Some do clip on properly, some fit ridiculously tightly (like Alex Atkin's) and some just come off without touching the clips (like yours and also mine). What you can do to improve this, with the faceplate off, is gently warm the clips that go into the master socket using your hands then gently and repeatedly bend them outwards. I did this to mine and it is now much better and doesn't fall off all the time.

I must point out, I wasn't touching the clips as the MK3 is right next to it due to nobody forseeing that Openreach would change the fitting method from screws.  I'd have to actually remove the MK3 to reach the clip on the MK4.  I was merely checking that the clips were working.
Title: Re: VDSL CAT6 Extension: Confused
Post by: mdesai on October 30, 2020, 12:56:23 AM
Hi

Thanks for all the replies. Good to know this is an expected result. Glad this forum exists ;D.

Careful not to resync the line too often testing sync speeds at various sockets.
Every resync counts as instability and too many will see the sync speed capped by the line management system (DLM) which can take months to reverse itself.
I think I have run into this. The next day by ping increase download speed decreased and upload speed decreased. Is there anyway to get the reserved quicker. I tried the 30 minute unplug of the modem

Another issue is I am trying to use a Huawei HG612 modem but am getting 5,000 kbps lower sync then the standard talktalk Huawei Router. (This was before I got capped due to repeated testing!) Any reason why this would be. I thought the HG612 is capped to 80meg so is plenty for my connection which maxes out at 35?

What you can do to improve this, with the faceplate off, is gently warm the clips that go into the master socket using your hands then gently and repeatedly bend them outwards. I did this to mine and it is now much better and doesn't fall off all the time.
I think the issue is also I am trying to run the extension through the back plastic pattress box. Since I am using Cat 6 external its too thick and is getting caught. I believe the new 5c is more ideal to use the cable entries at the bottom of the faceplate. The only option maybe to remove more of the outer sheath leaving just the twisted pairs then cutting a small amount of the sheath to cable tie to.

Thanks
Title: Re: VDSL CAT6 Extension: Confused
Post by: siofjofj on October 30, 2020, 08:02:02 AM
I think I have run into this. The next day by ping increase download speed decreased and upload speed decreased. Is there anyway to get the reserved quicker. I tried the 30 minute unplug of the modem
Yep, I'm afraid that sounds like the standard overnight DLM intervention in response to the data it gathered during the previous 24 hours. It sounds like interleaving has been applied. What are your upload and download sync speeds? If they are a round number (or very nearly a round number e.g. 29999 kbps) then additionally banding will have been applied. The 30 minute disconnection prevents the DLM seeing that particular event as instability, so if you need to disconnect again this is what you should do, however it will not do anything to reverse the intervention. As far as I know, the DLM relents quite quickly (say a week) after the first intervention, so my advice is to not touch it until it does. Subsequent interventions may take longer to reverse so be careful not to cause it again.

Another issue is I am trying to use a Huawei HG612 modem but am getting 5,000 kbps lower sync then the standard talktalk Huawei Router. (This was before I got capped due to repeated testing!) Any reason why this would be. I thought the HG612 is capped to 80meg so is plenty for my connection which maxes out at 35?
The HG612 itself doesn't have a sync cap set (other than the technical limit for VDSL2 profile 17a, possibly 150mbps), the 80mbps (or 40mbps, depending on the product you chose) cap is applied by the DSLAM in the street cabinet. Any modem will sync at the highest speed it can (up to the cap) given the condition and length of your telephone line. The HG612 is a decent modem, however there are better ones that will achieve higher sync rates and better stability. Modems with the BCM63168 chipset (e.g. Zyxel VMG1312-B10A) have been found on this forum to outperform the HG612 on most lines. Some people find that modems with Lantiq chipsets perform better. I don't know that is in your TalkTalk router, but seemingly the chipset in that is better suited to your line than the BCM6368 chipset in the HG612.

Since I am using Cat 6 external its too thick and is getting caught. I believe the new 5c is more ideal to use the cable entries at the bottom of the faceplate. The only option maybe to remove more of the outer sheath leaving just the twisted pairs then cutting a small amount of the sheath to cable tie to.
Another option you may wish to consider would be to terminate the Cat6 into the back of a separate RJ45 socket then link this socket with the one on the VDSL faceplate with a short patch lead. Even better would be to locate your modem at the master socket, then use the Cat6 cable to connect your modem's ethernet port to your router.
Title: Re: VDSL CAT6 Extension: Confused
Post by: mdesai on October 30, 2020, 03:26:17 PM
Yep, I'm afraid that sounds like the standard overnight DLM intervention in response to the data it gathered during the previous 24 hours. It sounds like interleaving has been applied. What are your upload and download sync speeds? If they are a round number (or very nearly a round number e.g. 29999 kbps) then additionally banding will have been applied. The 30 minute disconnection prevents the DLM seeing that particular event as instability, so if you need to disconnect again this is what you should do, however it will not do anything to reverse the intervention. As far as I know, the DLM relents quite quickly (say a week) after the first intervention, so my advice is to not touch it until it does. Subsequent interventions may take longer to reverse so be careful not to cause it again.

I don't think banding has applied (Screenshot added). Today My upload as reverted roughly where it was before. Ping has also decreased. Just download that is staying lower. Hopefully over the weekend it should resolve. At least I know to always disconnect for 30 minutes. It's a shame a DLM profile can only be reset by an OP engineer and not remotely by ISPs.

I'll look into getting a better modem. The HG612 is dirt cheap so thought it was a good choice since it was Openreach OEM equipment. The additional cat 6 faceplate with a patch panel is a good idea. May just crimp an RJ45 connector.

Thanks for all the ideas :)
Title: Re: VDSL CAT6 Extension: Confused
Post by: j0hn on October 30, 2020, 03:33:33 PM
The downstream looks like it has been banded at 32.4Mb
Title: Re: VDSL CAT6 Extension: Confused
Post by: mdesai on October 30, 2020, 05:14:34 PM
Is that good or bad?
Title: Re: VDSL CAT6 Extension: Confused
Post by: siofjofj on October 30, 2020, 05:19:22 PM
Is that good or bad?
Bad. It is a further step the DLM applies whereby it imposes a cap on your sync speed (in order to hopefully improve stability in the case of an actual fault) . Even though in this case it is not at a round speed, you can tell that banding has been applied from the downstream SNRM being increased above 6dB. Nothing to do but leave your modem in sync until it relents I'm afraid.
Title: Re: VDSL CAT6 Extension: Confused
Post by: mdesai on October 30, 2020, 05:25:42 PM
ok thanks
Title: Re: VDSL CAT6 Extension: Confused
Post by: j0hn on October 30, 2020, 05:54:04 PM
It's a rounded enough figure.
39,999 and 39,997 are essentially the same.

In this case it's 32,399/32,397.

32.4Mb is 1 of the banded levels often used by OpenReach.
The high SNRM confirms the line is banded/capped.

This is due to too many resyncs while swapping modems.
Title: Re: VDSL CAT6 Extension: Confused
Post by: mdesai on November 01, 2020, 08:13:37 PM
The quality control on the NTE5C and VDSL Mk4 SSFP combination seems to be quite poor. Some do clip on properly, some fit ridiculously tightly (like Alex Atkin's) and some just come off without touching the clips (like yours and also mine). What you can do to improve this, with the faceplate off, is gently warm the clips that go into the master socket using your hands then gently and repeatedly bend them outwards. I did this to mine and it is now much better and doesn't fall off all the time.

This tip is an essential for the MK4 SSFP plate. Completely fixed it! Can now hear a audible click when replacing it. Really made it solid. Almost as solid as screws. Takes a lot of effort to remove. Only now removes when you want it to by pinching both sides. Thanks for the tip  ;D
Title: Re: VDSL CAT6 Extension: Confused
Post by: neil on November 26, 2020, 08:29:05 PM
Welcome to the kitz forum.  :)

The effect is understandable and I can confirm that there is no fault. As you have extended the data port to the extension socket, the original data socket at the SSFP must not be used. When tested at the SSFP socket, the data extension wiring will appear as a bridging tap across the pair --  with the end result that you have observed.

wow 😲
what about telephone side? I have 2 phones and one is connected next to filter and other i think is 15-20 meters away but both are connected after the filter
Title: Re: VDSL CAT6 Extension: Confused
Post by: burakkucat on November 26, 2020, 10:23:48 PM
what about telephone side? I have 2 phones and one is connected next to filter and other i think is 15-20 meters away but both are connected after the filter

There will be a low-pass filter that provides the audio signal for the telephony side. The presence of that low-pass filter makes the telephony connections "invisible" to the higher, radio, frequencies of the xDSL circuit. Hence no bridging tap and no problem.  :)