BT Tested download speeds and actual Download speeds lower by a factor of 4x

[JSC]

I need to understand a problem that I have in that the tested line speeds of the BT router bears no relationship to the actual speeds achieved

BT  and other speed testers show download speeds of circa 4.5 - 5.5 Mbps (BT advise that Download speeds can reach 7Mbps) BT and other speed testers show upload speeds of  circa .48-.55 Mbps

The actual download speeds recorded on the computer are circa .5 Mbps to 1.1 Mbps

The actual upload speeds recorded on the computer are circa 46 -  55 Kbps

BT have advised that their tested speeds are the correct speeds and if I am not achieving them then it is nothing to do with them.

[Fiona]

Hi

Please run the test from http://speedtester.bt.com and see what results you get here. If you can then post these on the board we can explain what the results mean.

It is worth remembering, if you test your speed from a speedtester site in, say, America you are going through several different servers to get there which may be slow or congested. Also if you are testing your speed through downloads from different sites, again these may be busy or restricted and not give you an acturate download speed, just what you are downloading from their site.

Kind Regards

Fiona

BT Business Forum Moderator

[sej7278]

www.speedtest.net is the de-facto speed test site, it doesn't come from America it has test servers all over the world and you pick one local to you, like London. From that site I get 4.46Mbps/370Kbps

From the BT speedtester I got:

Download speed achieved during the test was - 4351 Kbps
 For your connection, the acceptable range of speeds is 600-7150 Kbps.
 Your DSL Connection Rate :7616 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
 IP Profile for your line is - 6500 Kbps

Which seems odd, why limit me to below 8Mbps?

the the modem/dsl reports 7.6mbps but the download tests both say around 4.4mbps, so there's some serious issue there.....?

[a-hill]

Hi sej7278,

the speeds you're seeing on the router are your line sync rate which usually matches your line profile, that's just the speed at which your router has synced with the exchange and isn't your actual throughput speed. The IP profile of 6500 is the cap rate imposed on the line which will maintain stability without causing errors. After your initial stabalization period, an MSR (maximum stable rate) and a FTR (fault threshold rate) are calculated. Max stable rate is as it suggests, the maximum rate you can expect your line to run in a stable mannor, and the FTR is the theoretical low end that we would expect the line to run before it would be considered slow and a fault. Your best bet is call the helpdesk on 0845 600 7020 opt2 and have them run a DSL Status Check on the line to see if you're breaching your FTR. Since ADSL Max is a rate adaptive service, we can expect to see fluctuations in the speed It's also worth noting that other influences on the line can cause this, such as faulty filters or phones causing noise on the line, or digital equipment such as faxes and cordless handsets interfering with the broadband signal.

[sej7278]

thanks for the response.

however it still seems strange that i'm rate limited to 6500 but still can't download faster than 4400.

i've not got any faxes etc plugged into the line and bt did the wiring, there's only one phone and the router in these premises, no extensions or anything.

[Fiona]

Hi

Broadband services are described as 'Up to' a certain speed. This is because high-speed broadband doesn't come as a fixed speed - it's flexible. Often, the speed you get will be automatically adjusted. This is to make sure you're getting the fastest, most stable broadband service that your phone line can support. Up to 8Mb is the maximum speeds, which you'd only see under perfect conditions. It is perfectly normal to have speeds lower than this.

The synchronisation (sync) speed is the speed at which your broadband modem or router communicates with the BT Exchange. This is always higher than the speed at which data will actually be downloaded over the connection. The sync rate is worked out by your phone line's characteristics, such as line length and quality. The shorter the line and the better the quality the faster the line will sync. From the test results you supplied it looks like your Sync Rate is 7616 Kbps, so this is the speed that your router and exchange are talking to each other and unfortunately not the download speed you would achieve.

The BRAS profile is responsible for regulating the maximum throughput (data rate) you will receive on your broadband service. Your BRAS profile changes when a stable connection has been made for a period of time; this may be up to 3 days in some cases. The BRAS Profile will also drop should the line rate decrease significantly. From your results, your BRAS Profile is set to 6500 Kbps, so this is the absolute maximum speed you would get on the line at that point, please don’t confuse this with a fixed download rate.

The throughput speed is the maximum speed that data will transfer across the connection. The maximum throughput speed is always lower than the sync speed. This is because the sync speed includes a certain amount of 'overhead data'. Essentially this is data that makes the connection work, rather than the data that gets added on to the web pages and files you download. Having the throughput speed lower that the sync speed ensures the connection doesn’t drop or become unstable.

This table shows the maximum possible throughput speeds for the different sync speeds you might see.

 

It's perfectly normal to see throughput speeds that vary throughout the day. Broadband works on a shared network. The available capacity on the network is shared out amongst all the customers that are using the Internet at that time. This means that at busy times, when more people are using the Internet, each person gets a smaller share of the bandwidth and so lower speeds than when the network is quiet. As different people use the Internet in different ways and have different usage patterns. This can mean that the speed you see can be constantly going up and down. We have the fair usage policy in place so people do not abuse the shared network, and makes sure the service can be used fairly by everyone.

In your case, I would test your line at http://speedtester.bt.com at different times of day, to see if you see any difference in your throughput speed. The tests results you posted are perfectly normal for a broadband connection and I am sure other customers on this site would agree.

If you see an issue with your connection speed on the BT Speedtester site when you have monitored it at different times of day, please come back to us.

I hope this helps

Kind Regards

Fiona

BT Business Forum Moderator

[DavidTC44]

I cannot even run  the BT approved loine testers.  Thgey time out.  AT&T tell me that the download and upload are .34MB.  I am paying for 4BM!  An explanation would be appreciated!