Router & Speed test Difference

Hi all,
I was on the phone to U.tv today trying to figure out the reason I can only get upto and about 3meg downstream, he asked me to go into my router home page and to check the ADSL status window , I did and the downstream showed - 7,000 kbps (7mbps??) Approx - but on the speed test on this site Iam getting 1.5mbps - 3.25mbps!
I went into the policy schedual, and took the % of retained bandwith right down to 0%, but didnt make any difference.

For info - currently running one phone cable from master socket to ADSL router with only the two main cable connected.

Any answers or sugestions are appreciated.

On ADSL Max there is a profile generated on your line called a BRAS profile, because the characteristics of the line can vary throughout the day, and can be much worse during the hours of darkness. You will only get a 7M profile if your modem/router reliably achieves 7M sync reliably over a 3-day period. If the speed drops at night, then the profile will be lower.

You will also get slower download speeds if the exchange is very busy, because ADSL is a shared service.

Edited by deleted (Sat 07-Oct-06 18:17:45)

I can go straight from the Speed test on ADSLguide - showing 3mb (max) to my router showing 7mb, and then back to ADSLguide and show maybe 2mb.

I may be wrong but that tells me that the line is coming in around the 7mb, but when it goes through the router to my system I can only use 3mb or less than 50%.

the Utv Support guy today mentiond the group policy edit that I tried, but it hasn't made a difference.

The speed of your BRAS profile has nothing to do with the speed that your modem is currently sync'd at. My ASL modem quite often sync's at 6M during the day, but I never achieve that speed, because my line SNR degrades at night, and I only get a 3.5M profile on the line. For you to get 7Mbps, your modem would have to be sync'd at that speed for 3 days with no sync speed drops, and you would also have to be connected to a service which is not being heavily shared with others.

Sorry zebedeee, I can just about follow some of that (have no idea what you mean all beyond me).
So is there any way I can get the bandwith through to my system?
Or is this as good as it gets?

cheers for the info zebedeee.

He is saying, rightly, that sync speed is one thing, but that actual throughput may be limited by many facters, including the Bras profile. Also exchange and ISP contention can be issues.

Not to mention throttling, FUP etc...

Have a look at the link below; gives a good deal of useful information.

http://www.adslguide.org.uk/qanda.asp?faq=technical

Just as an update on this;
I hardwired a line direct in to the mastersocket, (just wires 2 & 5) ran it straight to router, connected via a new Belkin microfilter, The rate thats coming to my router still says about 6-7mbps, but all tests show 1mbps, perhaps the odd peak at 1.5mbps.
for the techy's here's the latest details;

SNR Margin >down15.5 >up28.0 dB
Line Attenuation >down23.2 > up12.5 dB
Errored Seconds > down85 >up5
Loss of Signal >0 0
Loss of Frame >0 0
CRC Errors >526 >7
Data Rate >6912 >448 kbps
Latency INTERLEAVED INTERLEAVED

I cant get the BTspeedtester to complete, the ADSLguide wont show anything above 1.4mbps. Task manager > network confirms this.
I've adgusted the group policy to remove the withheld bandwith.
I've disconnected all other phone systems - sky & the portables downstairs.
Downloading a file mozilla shows rate at approx 175Kbps.

Iam not totally offay with the errors above.

Anyway, I've logged a call with U.tv, awaiting a test on the line will be interesting to see what they say.

G&W.

With those figures it ought to be contention, throttling or a stuck BRAS profile. If you can get the BT speed test to work, it will confirm whether it's the latter. Good luck.

worth checking at http://www.speedguide.net/analyzer.php or other tweak sites that your TCP/IP receive window or RWIN value is 64k or bigger. Small values can constrain data throughput.

You will have to persevere with the BT speedtester to find out your IP Profile, try early in the morning.

I think an analogy would be useful here.

You own a car that will go at a maximum speed of 100 mph. There are two things that can slow you down, a speed limit and traffic congestion. If the speed limit is 30mph it does not matter how fast your car will go, you are limited to 30mph. If the road is a motorway with a speed limit of 70mph but it is very congested - you may still only be able to go 30mph.

Maximum speed of 100 mph = your sync speed, say 6 mb/s
Speed limit = BRAS profile
Traffic congestion = Exchange contention

BRAS profile
You cannot download faster than your BT imposed "IP Profile", sometimes called your BRAS profile after the bit of equipment in the exchange that does the profiling.

Even though your router is synced at 6 mb/s the BT exchange equipment will always set your BRAS profile at a marginally lower figure. At 6 mb/s the BRAS profile will be around 5.5 mb/s and may be lower. If you do a speed test it will never show a result higher than your profile.

The BRAS profile is based on the lowest speed at which your router synchronised in the past 3 days. So although it may happily sync at 6 mb/s at the moment if at any time in the last 3 days it synched at (for instance) 2 mb/s then the BRAS profile will be set at about 1.5mb/s. The BRAS profile resets after 3 days, so if your router holds sync at 6mb/s for three days then it will reset your BRAS profile to around 5.5 mb/s.

Exchange Contention
Broadband is a shared resource. In simple terms, the more people there are on your exchange trying to connect, the slower your speed tests will be. Almost everyone has slow speeds in the evening. My router syncs at 8 mb/s and my BRAS is 7 mb/s but between 6pm and 11pm my speed tests vary between 2mb/s and 4mb/s. At 1am I can do speedtests at over 6.5mb/s (in other words when no-one else is using the internet I get the road to myself!). There is nothing you can do about this, it is down to how well BT equip their exchanges.

Fiddling with group policies, MTU, Rwin etc will make almost no difference to your download speed if your exchange is heavily contended or if your BRAS profile is set at a low figure.

If you cannot get the BT speedtester to show you your IP profile, do this speed test http://www.speedtest.bbmax.co.uk/ at 2:00 in the morning. This will be pretty close to your BRAS limit. If this is 5mb/s or higher and you still get slow speeds in the evening then I am afraid it is all down to BT exchange contention.

There are problems that can occur with the BT equipment such as "stuck" profiles so post back if your system does not sort itself out.

Speed test results in

Seem to be getting a bit of a lift on the line, seems that a moan in the ear of UTV worked so-far, but as far as I can make out from the speed test there may be room for improvement. but hopefully this will happen over the next few days.

Thanks to all who helped me on this.
The speedguide tester said my router was not set up properly, is there a utility or programme that can set this up? or do I have to figure it all out myself?

BT Speedtester - at 22:40hrs on 10th October '06

Results Image not loaded

Test1 comprises of Best Effort Test:
IP profile for your line is - 4000 kbps
DSL connection rate: 448 kbps(UP-STREAM) 6720 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 3711 kbps

That throughput for the quoted profile is quite reasonable, I think. The profile suggests that your router has dropped the connection and re-synched at lower speeds. For it to rise, you need a minimum of three days of higher-speed syncs. One low one and you start again.

I'm not sure what the tester meant about your router, never having seen the error message myself. Did it come with a setup CD?

Not that i can remember, there's not much in the way of Identification on the router itself.
Iam nearly sure its a conexant one, all it says is; 4 Ports ADSL Router , P/N 81180026 on the bottom and a serial number.
the router itself must be about 2 to 3 years old by now.

I wonder if it itself is limited as to what it can through-put?

It might be limited by what it can sync at but not what it will throughput. You might want to try a more modern router if you want to get the maximum sync rate for your line.

Your IP profile of 4000 suggests that you have had a sync in the last 3 days of around 4500 kb/s. Leave it until the weekend and do another test. If the system is working properly, and based on your sync rate of circa 6000 kb/s then it should increase to around 5500 kb/s and your download speeds should increase.

Just for clarification, the minimum sync speed for a 4000kbps IP (BRAS) profile is 4544kbps, and for a 5500kbps IP profile, the minimum sync is 6240kbps.
The router needs to hold sync, above the minimum, for three days before the IP profile will increase.

Another succesfull BT speedtest;

IP profile for your line is - 4000 kbps
DSL connection rate: 448 kbps(UP-STREAM) 7072 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 2997 kbps

As far as I can see, the possible connection of 7072Kbps has went up and the actual of 2997Kbps has went down, Will give it a few days and see what happens.

I was thinking about a more moder router today, could be money well spent

So Ade, would you agree with Last Man, that perhaps a more modern router would help the sync rate?

To be frank, your results are not at all bad. You have an IP profile of 4000 which is the maximum possible theoretical speed test that the BT exchange equipment will allow on your line. If you get more than 3000 for a speed test on a line with an IP profile of 4000, I would say that your connection is working well.

I am basing my suggestion that you may benefit from a new router on the fact that you have a 15db SN margin downstream. It should be nearer to 6db.

When you resynchronise your router the Exchange equipment will set the fastest rate it can to achieve a 6db SN margin.

If your router is showing 15db of SN margin this can either mean either of the following:

1. Your SN margin varies a lot between night (typically a low SN figure) and day and your router last did a resync in the night and you are looking at the stats during the day.

2. The BT equipment has set an unusually high SN margin for your line. BT will sometimes do this if the line conditions are particularly poor.

3. Your router is not fully compatible with a rate adaptive service such as ADSL Max.

Before you buy a new router you could try eliminating the possibility that it is 1 above by rebooting your router during the day. If it synchronises to the maximum speed of 8128 kb/s then it is likely you have a noisy line at night. If it still synchronises at around 7000 kb/s with a SN margin of higher than, say, 10db then it could be either 2 or 3 above.

Unfortunately I know of no way of telling for definite whether BT have set a higher than normal SN margin target for your line, so if you buy a new router it could still be no better than your old one.

It's possible, but it's equally possible that some of your line goes overground and is picking up noise. This is what my line does. My line will sync quite happily at 6M during the day, but drops down to 4M at night, and I end up with a 3.5M profile. This is because the prime source of noise (interference from MW/AM radio stations) gets stronger at night.

Finally Sorted, I knew there was more speed to be had!!

BT Speed test - 8am 17th October;

Test1 comprises of Best Effort Test:
IP profile for your line is - 6500 kbps
DSL connection rate: 448 kbps(UP-STREAM) 7616 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 6084 kbps

happy days, & thanks guys for all the help on this one.
Goes to prove the forum really works!!