FTTB - aber "slow" sync IB2

daffy2 · Apr 25, 2021

FTTB - aber "slow" sync IB2

I found the FTTB box in my building, in the parking garage 🙂

My IB2 still syncs rather slowly, at 137/56, although an availability test advertises 375/90 as the highest of all feelings.

The FTTB box is about 30m as the crow flies from my box, I have no idea about the cabling on the route.

What is the most suitable way to lift the current sync? Details from my IB2 below.

Thank you!

*************************

Measurements for your Internet accessMax. line transmission speedUpstream55961 kbit/sDownstream137850 kbit/s

Line attenuationUpstream6.9 dBDownstream10.9 dBSignal-to-noise ratioUpstream7.3 dBDownstream8.1 dBLast synchronization26 Days 16 h 3 minDSLAM chipset type (network equipment)BroadcomVectoringActivatedDSL datapump versionA2pvfbH043j2.d26uFEC since last syncUpstream8261310Downstream13012462

CRC since last syncUpstream36Downstream29

Lori-77 · Apr 25, 2021

Hello @daffy2

It looks like you have a small problem with your in-house cabling.

Because the CRC values should be close to 0.

Question: do you use Powerline? If so, remove them.

Have you also removed all the splinters? (also the old Y adapter)

A continuous U72 cable should be installed from the house connection to your apartment. There can only be 1 can.

And since when did you have the higher speed on the checker? It could also be that you still have the 1st gene of MCan and the checker already shows the expansion.

Greetings Lorenz

daffy2 · Apr 25, 2021

My home network is trivial: DSL comes from a box with the IB2 connected to it with a Swisscom cable. There is 1x RJ45 attached to the IB2, the rest is IB2 WLAN. In other words, from _the_ everything is as simple as it can be. Eight years ago, a Swisscom technician was on site and put the DSL on exactly this box (and it’s supposed to come from the box 😉).

Up to _the_ can - as I said, I have no idea, that’s how I found it. I think I still have PT&T lettering elsewhere in the apartment (the superstructure is roughly 1985). What measures can I take to ensure that I only have one continuous U72 cable installed? Inventory of PT&T / Swisscom labels?

I don’t check the checker regularly; it was pure coincidence that I saw the new values. The checker also says “Availability is currently limited” - can that also be translated into techie German? My real bandwidth actually matches the sync speed quite well; I don’t think I notice the CRC errors.

I know that a few months ago there was a major expansion of fiber somewhere “out there”; There is also a mini thing in front of the building, which I suspect is also part of the FTTB infrastructure (junction? Unfortunately, it must have had an accident, is crooked, and is wrapped in plastic). But I don’t know when the FTTB box was installed in the parking garage (also just a coincidence, today) - it could have been last week or last year /shrug.

POGO 1104 · Apr 25, 2021

@daffy2 wrote:

….Eight years ago a Swisscom technician was on site and had installed the DSL on exactly this socket…

That doesn’t sound bad - but that’s what your CRC’s say…

Your line should be measured - the hotline or our DSL professional can do this here @Roger G

Roger G · Apr 26, 2021

@daffy2:

The mCAN has been active since October 10th, 2019 and since then you can have at least 375mbps 🙂

8 years ago we were still in the Stone Age and no one was looking into digital telephony. The installation is therefore hardly up to date.

A measurement shows that you still have some nasty “BridgeTaps” in your apartment/house, i.e. the taps mentioned by @Lori-77. They have been there since the beginning of time and should have been removed after the switch to digital telephony. Rather, they produce such large interference that the IB2 cannot sync to g.Fast.

Remedy: Find the can that has a cover labeled T+T or TT. This can usually be found near the apartment door on the ceiling or at the top of a wall (but it can also be found in the stairwell). The box then contains the terminal where the cable comes from the basement (often white/blue pair of wires) and is currently distributed in a star shape over several pairs of wires to the rooms. Here you have to remove all but the one line to the router so that everything is correct. Don’t worry, there’s no power on it and even a short circuit wouldn’t harm the router, so you can go there yourself.

If everything is ok, simply switch the IB2 off/on and it will then start up at the appropriate speed.

Good luck 🙂

daffy2 · Apr 26, 2021

Roger G wrote:

The mCAN has been active since October 10th, 2019 and since then you can have at least 375mbps 🙂

😂Did I say that I started with 768/128? By the way, back then they still used the unit “k” and not “m”, and that was a dream after trrriilllerr-pfeiff-brrrrzzzzzzt 😂

@Roger G - thank you very much!

I have now found the right cable combination and now have the following values:

Say (up/down):


	before	after
Cushioning	6.9/10.9	3.⅜.1
SNR	7.⅜.1	6.2/9.5

That suggests that I should wiggle the cables again, right? While the attenuation appears to have improved significantly, the SNR, especially at UP, went from 7.3 db to 6.2 db - i.e. significantly worse.

The actually existing bridge through which everything flowed is definitely gone, now it looks like this (only the upper strand has been relocated):

POGO 1104 · Apr 26, 2021

The picture shows that completely unsuitable I51 cables are still being used with unsuitable terminal points.

A twisted U72 cable should be used, if possible without terminal points, and if so, suitable terminals should be used…

user109 · Apr 26, 2021

@daffy2 in the photo you can see I52 cable, not U72M!!!. I52 cable can have a lot of attenuation, i.e. less speed and also be very susceptible to interference (crosstalk). G.Fast has frequencies of up to 104 MHz on the DSL line, which is the VHF radio frequency. The cables photographed are unspecified and unsuitable for this purpose. It’s best to have the cables replaced; the flat rate from Swisscom (CHF 195) is usually covered by the landlord (please clarify in advance).

The whole installation is called BBR installation. (Broad Band Ready).

daffy2 · Apr 26, 2021

@POGO 1104 + @user109 - thanks for the info!

Is it correct that all of the cabling, from the Swisscom FTTB box (in the parking garage) to my socket, needs to be updated? That should be 30m across the development.

Are the following magic words suitable for the administration: "The existing cables of the telephone system are not suitable for the ultra-modern FTTB box from Swisscom in the parking hall. This leads to a rather poor connection quality to the Internet, with connection errors, which is particularly common in times of home office - A BBR (Broadband Ready) installation according to Swisscom’s specifications cannot help.

Where does the administration order the BBR installation? (In theory, my administration should know this, but practically speaking, I sometimes think there are some things they don’t want to know.)

And if the administration closes its ears - can I order the BBR installation for a flat rate of CHF 195 and, if in doubt, pay for it myself? Where?

POGO 1104 · Apr 26, 2021

Any sensible electrician should be able to do a BBR installation.

user109 · Apr 26, 2021

@daffy2 You can order the BBR installation via 0800 800 800. I hope the supporter comes with what you mean. Unfortunately, not all people are tech-savvy as they should be. A technician from Swisscom (Cablex) will come and replace the cables and issue you an extra invoice that you can easily pass on to the landlord.

Only the route UP (house connection) -> telephone socket router (apartment) is swapped. Incl. telephone socket (T+T83) on RJ45 Anschluss (purple).

user109 · Apr 26, 2021

@POGO 1104 wrote:

Any sensible electrician should be able to carry out a BBR installation.

@POGO 1104

That’s true, but most electricians don’t have a U72M 1×2×0.5, but only 1×4×0.5, which isn’t ideal.

daffy2 · Apr 26, 2021

Thank you everyone for your contributions!

I look at what the administration says, because in principle they have to approve the change through the BBR installation, even if they themselves couldn’t get around it anyway.

And then somehow it continues at some point with BBR and the FTTB box. 🤔

Roger G · Apr 27, 2021

Ouch… no advice is of any help here at the moment 😞 You were able to successfully fix the BT and I don’t see any measurable problems, but unfortunately this only resulted in 10mbps more in the DS. In the US I even see a little less speed.

When I look at this setup, only a handful sync on g.Fast (shocking). But then they’re pretty okay. The cause of the problems lies in the poor and very old wiring that was used at the time. I also see some corroded contacts, which significantly degrade the signal. So it’s entirely possible that everyone else’s problems and disruptions also have a negative impact on your line. The location is simply bad 😞

From the looks of it, no one will invest anything to improve the copper connections anymore. It is clear that people are more likely to wait for fiber optics here. But since it is a g.Fast FTTB location with 500+mbps, this will be at least. It will be another 1-2 years before we see glass in the apartments there.

My suggestion would be that you - or even several tenants - get in touch with the administration with the aim of having a technician in the building at least fix the UP, i.e. clean it, possibly insert new terminals, etc. replace cables It’s probably not possible, it will be too expensive for all parties. Unfortunately I don’t see any more options 😞

Good luck

daffy2 · May 3, 2021

Thanks again to Roger G for the feedback 🙂

I’ve been out and about for a bit and have now found the plan of my development, see below. The mCAN is circled above (the label has probably slipped); I’m down at “4161”. The distance between the points is approximately 76 m; I think I have found all the connection points.

What’s exciting for me now is the question of how to get a specific T+T box opened (== 4161?), which is probably the central distributor in the part of the house (for four parties): This looks like a negative Allen key (external hexagon ?), but the edge around it is extremely narrow? From _the_ I probably have bell wire, in the stretch before that I most likely know where it runs in the parking garage (the switches are all accessible under screwed sheet metal profiles under the ceiling).

Zoom:

daffy2 · May 3, 2021

@user109 wrote:

Only the route UP (house connection) -> telephone socket router (apartment) is exchanged. Incl. telephone socket (T+T83) on RJ45 Anschluss (purple).

@user109 What exactly does “house connection” mean?

I have the following route: mCAN -> 45m cable -> distributor (parking hall) -> 15m cable -> connector (parking hall) -> 17m cable -> house part distributor (?) -> 11m bell wire -> apartment distributor -> 6m bell wire - > “My can”.

For CHF 195 I’m happy to take mCAN -> “My Can”. 🙂

By the way, the installation as a whole looks very clean from the outside - but is there enough space for good cables up to the house part distributor (!)? There is definitely enough space in the cable pipe from the house part distributor, there is also an access point in the 11m, which would make rewiring easier.

user109 · May 3, 2021

@daffy2 House connection = UP (see picture you took T+T box) from there via the loop sockets (underground car park, apartment)

Pull a U72M 1×2 cable to your telephone socket where the router is connected.

daffy2 · May 10, 2021

user109

Final status after BBR installation:

Not a major change, from my point of view (which I didn’t really expect), but at least refreshed until I got my can.

Roger G · May 10, 2021

@daffy2 Did you do BBR yourself, or what did the technician measure on the UP?

daffy2 · May 10, 2021

@Roger G - I was able to convince the hotline that the “BBR installation” product was available at a flat rate. It also worked out economically - around 70 minutes of working time, material (at B2C purchasing prices),…

The Swisscom technician actually found that “only” around 150/50 came out on the UP (approx. 25m cable length from my socket). In this respect, even after BBR, I didn’t expect things to get better in terms of bandwidth.

Nevertheless, I hope that I have at least minimized interference from the UP to the apartment; The other bell wires (70m) are mostly behind sheet metal shielding - but still straight bell wire.

If time comes, advice comes, maybe at some point there will be an improved connection from the mCAN to me (to the UP). I have connection point “1”. Ta-da-di-ta-da-stupid. Hmmm.