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BT's super-fast Infinity broadband stuck in the slow lane
Tuesday 14 December 2010 11:49:40 by John Hunt

BT's latest and greatest broadband product, BT Infinity, which offers to deliver super-fast broadband speeds of up to 40meg has not been living up to its name. Users of the service have been reporting slows speeds on BT's community forums, with users seeing their service limited to speeds as low as 2meg in the evening until after midnight when speeds suddenly jump back up to the expected 30-40meg.

Users of the forum have suspected that the problem lies within the traffic shaping used on the BT network to throttle connection speeds to ensure that all users receive a fair broadband service without slowing down others to a crawl. Unhappy users have spent hours on the phone trying to get a fix to this but many have failed, and have resorted to contacting BBC Watchdog.

BT staff who have responded had been looking into it on an individual case by case basis as they did not believe this to be a general issue. We approached BT about the issue and received the following statement back from them:

"The slow speed experienced by a number of customers was due to a technical fault that was highlighted through individual complaints and our customer forums, this has now been fixed. We're sorry for the inconvenience and grateful to customers who highlighted this."

BT spokesperson

Users were still reporting issues last night so those affected will need to wait until this evening to see if the issue has actually been resolved.


Posted by 303pedro over 6 years ago
Wonder what has QoS priority? BT Vision by any chance? Traffic Shaping at its best (...or worst, dependent on your point of 'view')
What a disparity!
Posted by paulmsmith over 6 years ago
I'm a Business Fibre customer and believe I'm suffering the same issue.

When I download a podcast from Apple for example, it never goes higher than 4mb/sec should that be saying 40mb/sec?
Posted by john (Favicon staff member) over 6 years ago
paulmsmith: Check your units are correct. If it is saying 4MB/s in uppercase, that is the equivalent of 32Mbps (or 32meg) which wouldn't be too bad on a 40meg service. Try running our speedtest and see what that reports.

(the difference is the case of the b. Lowercase b means bits. Uppercase B means Bytes which are 8 times larger than a bit.)
Posted by infinidim over 6 years ago
This slowness seems not to be only with the new service. I am in Fareham and have been experiencing slow performance since about the 6th December on the BT 21CN WBC delivered service. I have now spent hours on the phone with the help desk and despite having a good sync rate between our house and the exchange we get a poor IP throughput.
Posted by paulmsmith over 6 years ago
Thanks for the info John. I just got this result:

I think maybe I am getting the full speed then? I have the TB speedtester before and its given me a better result than that.
Posted by PJWilkin over 6 years ago
I think BT's FTTC as a whole is broken. I'm with another ISP who provisions across BT's FTTC and suffer the same poor performance issues. I actually get worse (at times) on FTTC than I did on ADSL.

(A quick google shows lots of ISP's seem to have people with issues of slow performance on FTTC)

I suspect the FTTC system (which I gather uses the BT21CN network) is not up to the task of delivering more than ADSL1 or ADSL2 speeds
Posted by comnut over 6 years ago
rofl rofl - laugh! I almost bought a BT modem!!!! :D :D
been on VM CABLE 10M for years, glad I left the BT shambles behind!!

try - you can also compare your speed to others, change the server, etc...
Posted by GMAN99 over 6 years ago
You won't hear of slow user speeds on Virgin Cable of course ;o)

But seriously.. sounds like a bit of a shambles...
Posted by TGVrecord over 6 years ago
Looks like I am better off staying with Be's established broadband service which gives me a more or less constant download in the region of 14.5 Mbps
Posted by GMAN99 over 6 years ago
This does sound like a traffic management blunder than normal service though.
Posted by drteeth over 6 years ago
I don't know how FTTC works via BT wholesale, but my FTTC does NOT traffic manage at all and I can get my full speed 24/7.
Posted by otester over 6 years ago
This isn't traffic shaping, traffic shaping simply means the bandwidth available is prioritised for services that need it the most (latency sensitive->HTTP->P2P).

This is simply down to lack of bandwidth (result of overselling) if people aren't just confusing 2MBps with 2MBps, I doubt they'd be stupid enough to not invest enough to cater for the minimum guarantee of 5Mbps.
Posted by otester over 6 years ago
2MBps with 2Mbps*
Posted by otester over 6 years ago
Also I think it is down to confusion due to the level of intelligence you need to qualify as a BT customer.
Posted by GMAN99 over 6 years ago
otester - so they suddenly ran out of bandwidth? Ok throttling then, I don't believe they suddenly ran out of bandwidth, they've applied something (incorrectly) to the masses similar to when a user goes over the FUP by the looks of it.
Posted by undecidedadrian over 6 years ago
It sounds like somebody at BT towers instead of entering 300 gig as the monthly limit put something a lot less in as a trigger limit and has capped a ton of lines.
Posted by otester over 6 years ago

Traffic shaping doesn't discriminate against users but against types of traffic.

BT does restrict speed if you exceed 100GB, it could well be a swarm of heavy users from other providers that have jumped on to the Infinity bandwagon who otherwise wouldn't have gone with BT that are encountering problems.
Posted by GMAN99 over 6 years ago
Forget shaping otester, throttling or policing, whatever you want to term how they restrict your connection when you go over your FUP. That's what we are talking about here. Read on the forums this problem kicked in a 6pm and goes back to normal at 12am, its sound like an management mistake not bandwidth issues, it wouldn't suddenly hit everyone everywhere across the country like it has if it was a bandwidth problem. And its 300GB now not 100GB.
Posted by vm1990 over 6 years ago
im going with a diffrent option BT's network back bone cant handle the amount of users connecting at such high speeds during peak times

id like to know if the sync rate stays the same at all times?
if it does its traffic managment.
if not BT are fiddling the connection speeds so there "network backbone" dosnt bottle neck.
Posted by GMAN99 over 6 years ago
If it were bandwidth issues why would everyone drop to 2Mb? It sounds like an enforced rate limit, we'll probably never know. :|
Posted by otester over 6 years ago
The mass majority gets home at that time from work, hence 'peak time' and majority go to bed before our around midnight.

I've used a BT Retail connection during peak time before while round a friends house at uni, got ~2Mbps, same area I got 14Mbps 24/7.
Posted by GMAN99 over 6 years ago
I know when the peak hours are. Ok well.. differing opinions then, it seems too exact to me, running out of bandwidth would mean different people getting different speeds not all 2Mb. I doubt they'll fess up to the cause.
Posted by themanstan over 6 years ago
Strange, looking at the forums and what others who use ADSL2 are saying it looks like a BT goof on throttling logic. Everyone uses the same backhaul once the wires/fibres reach the exchange, so if there was a capacity/backhaul issue then everyone (copper users too)would be screaming.
Posted by torgo over 6 years ago
This has been a recurring problem for me since joining Infinity. Hope this marks the end but I am not closing the fault for now.

In general, I've had massive variability in downlink speed on Infinity - usually anything from 30Mb/s to 10 Mb/s. Uplink has been a fairly steady 8 Mb/s.

Also strange that the TBB speed checker routinely reports about half the downlink speed that reports (with BT's own checker usually coming in somewhere between the two, but closer to
Posted by anon123456 over 6 years ago
I suspected this would be a problem.

It wasn't long ago people were being fairly vocal about BT FTTC being a good contender against Virgin media 50mbit, especially with better upload. I pointed out back then, BT wholesale bandwidth is fairly expensive and it's the ISPs networks that are really the bottleneck here, especially during peak times. It was always a problem as long as I was with ISPs reselling BTW bandwidth.

It's such a refreshing change to be on VMs new 50mbit network, at least for now it's really fast for me, although some people are being traffic shaped now :/
Posted by GMAN99 over 6 years ago
Yep I hear of a lot of people getting snotty overusage emails on 50Mb now
Posted by herdwick over 6 years ago
" why would everyone drop to 2Mb " - Zen's product description for "up to 20M" states "It is likely that broadband speeds no greater than 2Mbps on Lite/Active/Pro services, and 3Mbps on Office and Office Max services, will be achieved at peak usage times." and a similar regime applied to MaxDSL.

So not inconceivable that all users would see same speed under congestion.
Posted by GMAN99 over 6 years ago
Herdwick, but that is being enforced though? uncontrolled bandwidth doesn't work like that, if there's no management, QoS, shaping, policing people will get varying speeds when you hit congestion, it will jump all over the place it won't be XMb for everyone.
Posted by BIORAPTOR over 6 years ago
[quote]Posted by GMAN99 1 day ago
You won't hear of slow user speeds on Virgin Cable of course ;o)

But seriously.. sounds like a bit of a shambles... [/quote]

I wish I could get Virgin round my area,I had a BT leaflet through he door about Infinity although I am in consideration on weather to make the change or wait until another optic ISP comes along?.
Posted by infinidim over 6 years ago
My thoughts are it could be to do with the bRAS profile. I have had issues with my "Upto 20 Mb" BT service. The sync rates are quite good (1600 m approx cable distance) - upstream 15106 Kbps, downstream 1048 Kbps, IP profile 13000 Kbps - yet I only get about 7863 Kbps IP downstream throughput out of the link.... this looks like my bRAS profile is set too low for the sync rate. This might be happening with the FTTC services as well between 1800 and 2400 to stop congestion. Anyway those are my thoughts on it. I continue my ongoing fight with BT to try and get a stable downstream IP throughput.
Posted by herdwick over 6 years ago
"uncontrolled bandwidth doesn't work like that" - but it isn't uncontrolled, shirley. Otherwise you can't have "Max Premium" with peak time priority etc.

@Infinidim a 13000 BRAS profile isn't going to limit you to 7863 even if it should be a bit higher.
Posted by GMAN99 over 6 years ago
I know its not uncontrolled which is my point, if all people are getting 2Mb that is an artificial limit that is set
Posted by infinidim over 6 years ago
My situation looks like it is being resolved. It looks like BT Wholesale have not been monitoring the DSLAM to bRAS path out of Fareham exchange and let it get overloaded.
Posted by elder666 over 6 years ago

I had the same problem until I plugged my laptop into router via Ethernet.

If anyone you are still on a Wireless G or less then upgrade to Wirless N adapters otherwise you'll notice slower download speeds.

On a Wirless N connection now and 20Mb plus, 30mb+ vis ethernet.

Wireless G 8MB or less.
Posted by elder666 over 6 years ago
p.s. I'm in N.Ireland where ADSL has been stuck at 512 and less connections since ADSL Max was born so well Done to BT for ungrading my street and exchange. I can now finially work form Home ;-) and dump my 3G setup ;-). Bring on the snow ;-).
Posted by elder666 over 6 years ago
Posted by RAConnell over 6 years ago
This type of BT service is the very reason I switched from BT to BE getting a BB speed that is 3x faster. BT are just a con service and I'd have no faith in getting a BT infinity speed anywhere near 20 Mb. BT's business approach is to provide more customeres with a poorer service.
Posted by roughbeast over 6 years ago
I'm so glad I'm on VM. Unlike BT they offer excellent TV and the FTTC broadband delivers what it says on the box. I started with VM on 10Mb, got upgraded to 20Mb for free and am now on 50Mb/5Mb. Always I have had full delivery of the paid-for speed, with no outages.Looking forward to 100/10.

BT are going to have to better than this if they want people to believe in their rather excellent ads campaign..
Posted by spikealight over 6 years ago
It is not only fibre users that have been affected. My father in law signed up to BT Broadband on the basis of 5.5mbs estimate (I get 6mbps in the next street from Be, so thought it correct) but only gets 1.7mbs (less than his old service with Orange). The unknown factor is that our exchange was converted to FTC around the same time!
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