Second FTTC line - issues with crosstalk?

I was considering getting a second FTTC line but wondered about issues I might have with crosstalk.

My existing FTTC line was working very well. As more and more took up the service I'd notice a slight increase in CRC errors up until my next door neighbour got FTTC and suddenly it dropped about 30Mb of attainable sync. I assume I must be sharing the same pair with them?

If I got a second FTTC connection is it likely the speed would drop further? Is it likely BT would have to run a new cable for the new line? The phone cabling is from underground ducting.

I was considering using a CISCO RV042G to load balance between the two connections. Are there better models for the same money?

Not seen enough examples of this to say what happens real world wise, but should be no worse than sharing the local loop for 200m or more with the other VDSL2 users.

Just make sure you are using twisted pair wiring through on the VDSL2 side.

Thanks Andrew. That's great advice.

So I understand that my cable comes to me from the cabinet, along with all the other telephone users. What I'm slightly less clear on is why when my opposite neighbour got FTTC all I saw was a bit more noise same with the neighbour on my right but when the left hand neighbour got FTTC loss of 30Mb. Does this mean they're closer somehow to my cable?

And seeing as I'm already with Plusnet should I go with BT? Sky? Talktalk for the second line? I know I'm just asking for opinion I already have Sky TV!

Go with another ISP then if PlusNet goes bad there's a good chance of the backup working. Sky are doing half price on 40Mbps product for 6 months (so £10) & if you give them a call they can sometimes offer even more incentives. I rang through to cancellations saying I couldn't get a good deal on fibre and first time got turned down, I re-rang and got line rental for £1 for a year At the time there was no half price etc though but worth a shot!

If you've lost 30Mbps in one hit then I think you can report that as a fault, if you lose 25% of speed in 14 days it is classed as a fault.

How much crosstalk affects your line depends on how close it is to other cables, how long they run side by side etc. The latest one may run right next to yours, where as the other may not be so close.

Of course the other reason could be that the engineer disturbed something when installing the latest connection, either way it looks like you can report it as a fault, hopefully your ISP can back this up with speed evidence.

He only said he'd lost 30 Mbps of attainable, not actual speed. Is there any actual loss? Personally I couldn't care less about the reported attainable speed, only what I actually get.

I've lost about 10Mb of sync speed and it's still 5Mb above my original estimate and now 15Mb above the current estimate.

What I'm really after is resilience - a bit more speed would be great. But I don't want to add a new FTTC line if adding it will take off another huge loss of (theoretical) speed.

Sky is certainly one of my current front runners along with BT.

Of course if I go with BT I'm being resilient to ISP loss whereas with Sky I get resilience along a different path as well as ISP.

If its resilience, then I'd have one FTTC line and one ADSL2+ line.

Thus if the FTTC cab dies your ADSL2+ still runs, then once Fibre on Demand appears order that for one of the lines.

I missed the attainable bit, that was only mentioned in the first post, not the second (the one I replied to) where he only mentions losing 30Mbps.

yeah I think you will get nowhere, I caused myself loads of hassle for nothing trying to fix something similiar.

Few things to consider. The 25% in 14 days things means openreach should come out and have a look but thats it, they can still easily say "nothing we can do line passes test".
It has to be actual speed, a line that has a 150 attainable dropping to 120 attainable is 0 speed loss.
If line is still above estimated speed then I think there will be an even harder time getting something done about it.

In my case I had a estimated speed of 65.9, the sync started out at 80 with 110 attainable. A 25% speed loss would need it to go below about 60. So I would have needed to lose 50 attainable speed. Instead I had 2 large drops of attainable a week apart from each other, both within a month of my line going live. I first went from 110 to 90, then the 2nd time from 90 to about 73. My effective speed loss was from just 80 to 73, not even 10%. I didnt report it. However later another issue occured on my line which was causing bursts of errors in the early hours of the morning, and DLM was pushing my line down to speeds below 40mbit. This I did report. BT showed up said they couldnt find a fault, JDSU passed etc. the engineer also claimed a 80mbit sync is impossible and I was mistaken I originally had a 80mbit sync, and that the install day 110 attainable he was in complete denial. After he gone, the early morning issues mysteriously dissapeared, in addition my line stopped occasionally jumpng to 90 attainable (prior to visit my attainable kept jumpng up to 90mbit). I used a fritzbox 3370 to accelerate DLM reverting my line and I ended up with for a while on a sync in the high 60s until about 2 weeks ago the attainable went back up to 73-74.

Personally I would be surprised if you had a 2nd FTTC line installed on he same dropwire and had no affect on sync speed on the 1st line.

I share a dropwire with my neighbour who has FTTC, I had a extra engineer visit (after I told BT I am a samknows tester, they decided I merited another visit) this engineer installed a new dropwire dedicated to myself, my attainable shot up to a speed higher than my install day. But then the area manager made him undo the work stating its against BT policy, so I am back on the shared dropwire.

I'm in the same boat but consider if you really need failover or you want to bond them.

The only sensible option for failover is to take an ADSL line back to the exchange, so I have a second line on ADSL at 2mbps and the primary FTTC at 60mbps.

The speed differential is huge making the ADSL line useless, however I really wanted backup (however slow) and two FTTC lines to the same cab is not really backup.

Although FTTC service is flawless so far I can't view that box at the end of my street as long term reliable as the kit at the exchange. I appreciate that I don't have two diversely routed physical wires but hey-ho, this is all you can do at home.

I have underground ducting and when I enable the second ADSL line it has a tiny effect on the FTTC line, maybe a 1mb or two from attainable. (Not the same as a second FTTC line I know but for comparison)

I'm using pfsense firewall to terminate the links and load balance.

Thanks for that really helpful article. I'm starting to understand some of the pain you must have felt when your line went bad and there's no reason for it other than crosstalk. Then to be told by BT that it's not policy to have a dropwire exclusively serving your property is definitely not customer friendly. I guess we all live in hope that vectoring will be adopted and rolled out quickly by BT.

Looking at all the posts it seems to suggest that it's quite likely that an additional line with ADSL/VDSL is likely to affect the existing service, so I think it's unwise for me to start paying for additional services when they might adversely effect my existing low latency connection.

FTTP seems to be the way for me even with it's relatively high setup costs. As an additional question... The Fiber aggregation node that Openreach talk about. Is that usually at the FTTC cabinet, the original CAB or somewhere entirely different. I only ask because my CAB is about 130m from my house and the FTTC cabinet about 90m.

In reply to a post by Magsy:

The only sensible option for failover is to take an ADSL line back to the exchange, so I have a second line on ADSL at 2mbps and the primary FTTC at 60mbps.

And what happens when a failure occurs on the cabling from house to cabinet or the duct from cabinet to exchange?

The only way is fully diverse routing.

Separate drop wire to a different pole. From pole to a different cabinet and from that cabinet to a different exchange.

Yeah I agree... and in my case I could make at least one alteration to my setup which would make it more resilient to power failures (which we've had a fair few recently) by fitting a UPS.

But yes I guess we'd have to define what type/level of resilience we're after and how much it costs to implement.

I have two FTTC lines, one Sky and one BT. I ordered the BT line 2 days into a 5 day internet outage when Sky tried to switch my existing ADSL to FTTC (long story...).

They both connect to the same cabinet so there is not much in the way of diversity. However when Sky is congested or goes offline then I have BT, and vice versa. So protection against provider outage, but not local issues.

The new BT line was wired into a spare pair of wires in the existing phone cable (which, incidentally, had already been used for Sky but were switched).

I use pfSense on a commodity PC (though expensive Intel NICs), which provides WAN load balancing. It doesn't work for everything, of course, but surprisingly many protocols split their requests and often provides around 90% of total bandwidth. The speed test on this site will report ~28MBit/s for the single HTTP thread and 54 for the 6x threaded test. Of more value is the ability to send latency-sensitive protocols down the 6ms BT line and have stuff like video use the 30ms Sky line.

I have not noticed any significant issue with crosstalk. My Sky line dropped from 31 to 26MBit/s in the two months before getting the BT line installed, and has remained there since. This is probably due to other people getting FTTC - I was first on my cabinet. The BT line hasn't moved from 28Mbit/s since installation.

thats good to hear.

In reply to a post by nOw2:

I use pfSense on a commodity PC (though expensive Intel NICs), which provides WAN load balancing.

pFSense seems to be a good choice from your post and some of the stories I've read elsewhere. It probably handles PPPoE connections more efficiently. I like the report graphs too.

BT and Sky seem to be a popular combination. I wonder what makes your Sky line have such poor latency compared to the BT line.

I was told by another poster here it's because the lines are different, but as mentioned they have actually been physically switched. I didn't have the energy to argue.
I've always seen poor latency on Sky, even on ADSL - where Zen provides 14ms Sky was 25ms. My FTTC was provided at 20ms then jumped to 30ms after an IP renewal (!). I just put it down to Sky's network - I'm at the end of their rather ramshackle network in north Wales.
I would actually not recommend using Sky if you use the line for business (their T&Cs actually forbid it) but you definitely want an LLU provider and Sky do have a network about as separate from BT as it's possible to be.

Maybe down to the default profile that BT and Sky order. They have a choice of 3 DLM profiles, willing to bet Sky pick Stable which will mean deeper interleaving depth on FTTC.

This is the only DLM control the provider has on FTTC.

I have 2 FTTC lines too, one with plusnet and one with BT. Both modems are connected directly to a Draytek 2920n.

Both lines are fed from the same cable to the house and seem to work ok. I get 45mbit on one and 50 on the other with full upload on both lines.

The lines got installed on the same day, initial speeds were 50/20 on each. The plusnet has dropped slightly where the BT one hasn't. I was 6th on the cabinet, So I expect one line has been a little bit more susceptible to crosstalk. Oddly for gaming my plusnet line is about 10ms fast ping wise to most servers, so it could be different interleaving levels.