BT Infinity - guaranteed speeds

I switched from TalkTalk ADSL to BT Infinity 1 in January 2017. My postcode is LE9 2EH and according to the BT Broadband Availability Checker, my connection to KIRBY MUXLOE Exchange is served by Cabinet 15.

Cabinet 15 is 285 metres from my home. The copper connection runs underground for 50% of the way. Then, it passes between three telegraph poles, before dipping underground again. Consequently, there will probably be at least five joints in the line.

BT provided a Home Hub 6 router which seems to work OK. My Windows 7 desktop computer has a wired connection to the router. My Windows 7 laptop and several Android devices connect via Wi-Fi.

When I switched from TalkTalk, BT estimated my download speeds would be between 54Mbps and 55Mb, with upload speeds between 9Mbps and 10Mb. I rarely achieved 54Mbps, although I usually achieved the minimum guaranteed speed of 50Mbps.

More recently, BT upgraded their Infinity 1 service to some subscribers at no extra charge. So in September 2017, I noticed a significant increase in download speeds. That lasted for a few weeks and on one occasion, my speeds peaked at 83.13 Mbps (up) and 17.42 Mbps (down). See https://www.thinkbroadband.com/speedtest/15066049535...

Then, performance became erratic but subsequently stabilised at around 56 Mbps / 16 Mbps (tested, using a wired connection to my router).

The BT Broadband Availability Checker quotes the following figures:

VDSL Range A (Clean).
Downstream (Mbps) High 80, Low 65.4. Upstream (Mbps) High 20, Low 19. Downstream Handback Threshold (Mbps) 55.7

VDSL Range B (Impacted)
Downstream (Mbps) High 78.3, Low 51.9. Upstream (Mbps) High 20, Low 15.3. Downstream Handback Threshold (Mbps) 39.8

I have just re-contracted with BT for a further 18 months, in return for worthwhile discounts. BT�s confirmation email estimates my download speed will be between 67Mbps and 80Mbps, and my upload speed will be between 19Mbps and 20Mbps. The minimum guaranteed speed I can expect should be 60Mbps.

I cannot achieve the minimum guaranteed speed of 60 Mbps and present average download speeds are usually around 55 Mbps, as per the speed test at https://www.thinkbroadband.com/speedtest/15138528687...

My router stats are as follows:

Product name: BT Hub 6A
Serial number: +084316+NQ64155250
Firmware version: SG4B1000B316
Firmware updated: 28-Sep-2017
Board version: 1.0
Gui version: 1.64.0
DSL uptime: 12 Days, 22 Hours 53 Minutes 28 Seconds
Data rate: 19.00 Mbps / 60.00 Mbps
Maximum data rate: 23211 / 77309
Noise margin: 15.8 dB / 10.3 dB
Line attenuation: 16.8 dB
Signal attenuation:
VPI / VCI: 0/38
Modulation: G_993_2_ANNEX_B
Latency type: Fast Path
Data sent / received: 13237 MB Uploaded / 12258 MB Downloaded
Broadband username: [email protected]
BT Wi-fi: Active
2.4 GHz wireless network name: BTHub6-RGPC
2.4 GHz wireless channel: Channel 11
5 GHz wireless network name: BTHub6-RGPC-5
5 GHz wireless channel: Channel 36
Wireless security: WPA2 (Recommended)
Wireless mode: Mode 1
Firewall: On
MAC address: AC:84:C9:B2:0F:B9
Software variant: -
Boot loader: 7.33.1

My connection appears to be very stable, and I have suffered no dropouts within the past 12 days. However, I do not understand why the router stats show a data rate of 19.00 Mbps / 60.00 Mbps, if the maximum data rate is 23211 / 77309. Consequently, I wonder whether BT have imposed a cap.

Any advice would be appreciated.

Can you describe your set up please, what�s connected to what, and how in your property ? ( I�m talking telephone sockets, filters, etc)

The telegraph pole outside the property serves two houses. An overhead wire from the telegraph pole enters my home and terminates in a BT Openreach master socket, which was installed by Openreach several years ago. (see image at https://www.dropbox.com/l/scl/AADFEpDAswqbH-DHbYo4_q...

There is nothing plugged into the front of the master socket, but there are two wires connected to the rear of the faceplate. The first wire goes into my loft and splits into branches, which serve extension sockets in several rooms. All of the bell wires were disconnected a while ago. Three devices are plugged into these sockets (and each one has a filter):

Sky receivers (2)
BT6500 telephone base unit

The second wire, which is only three metres long, serves an extension socket in the adjoining room. My router, the fax connection from my printer/scanner and an ordinary telephone are connected to the extension socket (via a BT filter).

I hope this helps.

Edited by bob_lucas (Sat 23-Dec-17 13:33:06)

Your link doesn't work for some reason ?

But from your very clear description (thank you) I is obvious that your internal set up is causing a 'bridge tap' fault. This will almost certainly be what is causing your speed issues.

I'm guessing your linked photo showed a 'normal' NTE ...... Is it possible to remove the front faceplate (causing the two attached extensions to be disconnected) Then plug the router in the test jack in the back of the NTE ... if possible post the same stats from the router again, this should show a pronounced increase in max attainable sync ....... Throughput won'y show any different due to a DLM cap.

Easiest next steps for you as a BT Retail customer is to ring them, explain your lack of speed (and no more) and hopefully they'll arrange a 'Broadband Boost' visit from Openreach .... a bit of jiggery-pokery with the wiring, and you'll be sorted.

Post deleted by PaulKirby

Edited by PaulKirby (Sat 23-Dec-17 15:03:05)

Thank you for your helpful reply.

I don't know why you were unable to view the picture. (I wish thinkbroadband would allow subscribers to upload picture files directly to the forum). However, I agree with your assumption that I probably have a standard NTE5 or NTE5A master socket. The master socket, which is clearly labelled Openreach BT, has a single output faceplate. I vaguely recall that when the Openreach engineer installed it, he said it was the latest version, which included a bell wire filter. It is not a NTE5C (with a curved front).

Your reference to a Bridge Tap prompted a Google search which in turn, led me back to the BT Broadband Availability Checker. I hadn't noticed the additional information at the foot of the page, which said:

Premises environment - Bridge Tap No; VRI No; and NTEFaceplate No. Last Test Date 14-05-2017.

I don't know whether that proves conclusively whether broadband performance is, or is not affected by a Bridge Tap. Furthermore, the quality of the ancient copper cable between the Cabinet and my home is also suspect and over the years, I have experienced far too many line faults.

Unfortunately, further investigations using the test socket will have to wait until after Christmas, because the socket is in an inaccessible position behind heavy furniture. However, I will go down that route as soon as possible. I presume there would be no charge for a call-out by a BTOR engineer, for a Broadband boost.

Incidentally, would it help, if I replace the master socket faceplate with a Pressac (or similar) filtered faceplate, which has separate voice and ADSL connections? If so, I could run a Cat 5 wire directly from the data terminals at the back of the filtered faceplate to a new outlet box and RJ11 socket, behind the router - and connect the telephone extensions to the other terminals.

Edited by bob_lucas (Sat 23-Dec-17 16:08:17)

Really not sure why that checker says no to a bridge tap ? But then these things aren�t 100% assured.

Not sure if your solution with the Pressac would achieve the same , but that�s because I�ve not tried one.

If you go the Boost route you�ll get an end to end pair quality test and verify the pair itself. Plus the engineer can do a DLM reset once they�ve resolved any issues.

I don't know why you were unable to view the picture.

Quite possibly because ). has been added to the end of the url. Removing the ). I was then asked to log in to view the picture something I thought would have been unnecessary.

I can't see it even having signed in and removed the ). I'm getting You don�t have access to this content. You�re signed in as ....

In reply to a post by RobertoS:

I can't see it even having signed in and removed the ). I'm getting You don�t have access to this content. You�re signed in as ....

Should be OK now.

I shall have to find a different way to upload pictures. Dropbox used to be fine but now, it doesn't seem to permit third party access to files, even if I enable sharing.

Dropbox have upgraded their systems and introduced different ways of sharing files.

Anyone who tried to use the previous link had to sign in with a Dropbox account. Then, I needed to authorise each request.

The following link is different, and should provide unrestricted view access to everyone.

https://www.dropbox.com/s/txp4gn9wwfp49av/master%20s...

To get the best out of your line, you need to plug your router into the master socket and add an SSFP filter to it which will then stop the broadband signal going down your telephone extension cables. As already mentioned you do have a bridge tap present, and this is the reason for your slow speeds.

To resolve it, plug the router into the master socket with one of these fitted to what you already have in place https://www.ebay.co.uk/itm/Genuine-BT-Openreach-MK3-...

If your desktop does not have a wireless connection, then you might want to look at either running an ethernet cable from where your master socket & router will be located (master socket location) to your desktop, or if that is going to be a problem, look at getting some power line adaptors.

Totally up to you, but the only real way for you to get the best out of your line is for the filter to be fitted and your router moved to the master socket from the extension socket. If you call OR out, then if everything is ok at the master socket, then you could be looking at a potential charge for the visit, as the problem will be classed as customer cabling (extension sockets).

Hope that helps

Yes, I know they have. IIRC it was to do with security, with the original being too each to hack.

They have changed at least twice. The intermediate one was almost impossible, the latest I have managed to get to work, but more by luck than good judgement.

Anyway, I have now seen yours thanks to your authorising it. It is a bog standard NTE5A for anyone who wants to know.

It is not practicable to site the router permanently by the master socket. However, was able to connect it temporarily to the master socket, where I performed some additional tests. I used an Ethernet wired connection between my computer and the router and I disabled the Wi-Fi adaptor on my computer.

For the first test, I connected the router to the master socket faceplate (i.e. the telephone extensions were still connected to the llne). The router statistics were:

Product name: BT Hub 6A
Serial number: +084316+NQ64155250
Firmware version: SG4B1000B316
Firmware updated: 28-Sep-2017
Board version: 1.0
Gui version: 1.64.0
DSL uptime: 0 Days, 0 Hours 13 Minutes 40 Seconds (please ignore, because I needed to re-boot the router, when I moved it)
Data rate: 19.00 Mbps / 60.00 Mbps
Maximum data rate: 22786 / 71933
Noise margin: 7.9 dB / 8.8 dB
Line attenuation: 17 dB
Signal attenuation:
VPI / VCI: 0/38
Modulation: G_993_2_ANNEX_B
Latency type: Fast Path
Data sent / received: 1 MB Uploaded / 3 MB Downloaded
Broadband username: [email protected]
BT Wi-fi: Active
2.4 GHz wireless network name: BTHub6-RGPC
2.4 GHz wireless channel: Channel 11
5 GHz wireless network name: BTHub6-RGPC-5
5 GHz wireless channel: Channel 36
Wireless security: WPA2 (Recommended)
Wireless mode: Mode 1
Firewall: On
MAC address: AC:84:C9:B2:0F:B9
Software variant: -
Boot loader: 7.33.1

A Thinkbroadband speed test reported an average download speed of 53.9 Mbps. (https://www.thinkbroadband.com/speedtest/1514809468110844155 ).

Then, I plugged the router into the test socket (with no extensions connected to the line) and repeated the test.

The Thinkbroadband speed test result suggested a slightly slower average download speed of 52.4 Mbps. (https://www.thinkbroadband.com/speedtest/1514810767641781855 )

All of the router statistics were the same, except the Maximum data rate of 22786 / 71933 had increased to 25775 / 82802; the Noise margin had changed from 7.9 dB / 8.8 dB to 16 dB / 11.8 dB; and Line attenuation had reduced from 17 dB to 14.4 dB. Significantly, the Data rate of 19.00 Mbps / 60.00 Mbps remained unchanged.

So plugging the router into the test socket had made little difference.

Finally, I performed a BT Wholesale Broadband Performance Test, which produced the following results:

Download 54.36 Mbps
Upload 15.12 Mbps
Ping Latency 33.13 ms

The test reported a download speed of 54.36 Mbps, which was similar to the results of previous Thinkbroadband speed tests.

You can view the complete result of the BT test at https://www.dropbox.com/s/q440noqxdtkzbz0/www.speedt...

Significantly, the BT test indicates that the IP profile for my line is 55.58 Mbps and the acceptable range of speeds is 40 Mbps to 55.58 Mbps. That differs from the BT offer letter, which stated:

We estimate your download speed will be between 67Mbps and 80Mbps, and your upload speed will be between 19Mbps and 20Mbps.

The minimum guaranteed speed you can expect from your broadband will be 60Mbps.

I wonder whether BT have applied an incorrect profile to my line, because there is no way I could achieve a minimum of 60 Mbps, if the profile is capped at 55.58 Mbps.

From your post ....

"Data rate: 19.00 Mbps / 60.00 Mbps
Maximum data rate: 22786 / 71933
Noise margin: 7.9 dB / 8.8 dB"

Shows that with a DLM reset, and an SSFP on the NTE you could be getting pretty close to 80 meg download sync.

What is capping your throughput speed tests is the IP profile system.