BRAS is dead

[kinmel]

It appears that the dreaded BRAS Profiles have been killed off.

My A&A broadband control panel now shows the actual throughput rather than a profile..........

13 Dec 10:10:17      Line rate now 4713000   -BT-
9 Dec 18:17:07      BRAS 3M to 3M/828K, Opt In, 2011-12-08 17:49:15   -BT-

I am suffering the usual Christmas lights syndrome with the  SNR jumping up and down with subsequent connection rate changes. The changes pushed my profile down to 3M on the 9th, but a new sync of 4731on 13th gave me an instant throughput of 4713 !

At last BT are trying to get the best out of their system, rather than run it simply for their own benefit.

Are Idnet lines being treated in the same way?

[Lance]

I've just run a BT speedtest and it still shows a profile. What happens if you run one?

[.Griff.]

Saw this on Twitter earlier in the week - http://aa.net.uk/news-2011-faster-21cn.html

21CN BRAS steps
It seems BT are not longer running the BRAS rate limiters for 21CN lines (ADSL and FTTC) in the distinct 1M steps as before. It appears that the rate limiting is the line rate now.

Again, without a clear briefing, we cannot be sure this is all 21CN lines yet, but it seems to be the case on the ones we have checked.

The main impacts of this are (a) you do not lose up to a megabit because of the BRAS rate being in distinct steps, and (b) you do not have to have to wait after a sync speed change for BT to apply a new BRAS rate (can take hours). Also, of course, all of the possible error cases where the BRAS rate does not match no longer apply.

What we have changed
The main change we have made today (13th Dec) is that for 21CN lines we are no longer applying the BRAS rate update messages we get from BT but instead we are now using the rate we get when you connect. This will take effect next time you connect and show the rate on your control pages as the BRAS rate. Some BT tests still report the old BRAS rate system in the logs though. We will probably do an LNS upgrade at the weekend meaning all 21CN lines will update, but if you want this sooner you just need a PPP kill on your line to pick up the new speed.

These changes are particularly useful when they apply together as we have seen FTTC lines gain significant speed (e.g. 30M to 39M) and not update BRAS rates.

[kinmel]

I've just run a BT speedtest and it still shows a profile. What happens if you run one?

the BT speed test shows a "profile", but that profile is not the 3Meg the old system would penalise my recent disconnects with.

Whenever I resync now I instantly get a new profile that matches my new line speed.

[Steve]

I can't see my sync but got suspicious of something strange when the profile went from 38710kps to 38718kps . I believe AAISP limited an individuals throughput in their network to the advertised BRAS rate, this may be standard ISP practise    so all 21CN may gain a bit more if max throughput is at sync rate.

[Aaron]

I wonder if this affected my ADSL Max? Two nights ago my router lost sync and synced at a higher rate - 4640kbps. This was very odd, as I normally sync on 4200-4300 in the daytime and 3300-3800 if it's done in the night. Surprising to get this high of a sync at 1am.

But my IP profile has dropped to 2000 from 3500 from this higher resync as a result What gives? It should be at 4000. Horrible 2mbit download speeds!

Your DSL Connection Rate :4640 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 2000 Kbps

[Steve]

If it's stable at that sync rate  and you've still got the 2k IP profile on Monday, you need to talk to support. Occasionally they get stuck and need a helping nudge from BT.

[kinmel]

I believe AAISP limited an individuals throughput in their network to the advertised BRAS rate, this may be standard ISP practise    so all 21CN may gain a bit more if max throughput is at sync rate.

BT imposed the BRAS "speed limits", not any ISP.    AAISP, just like Idnet, do not do throttling, or port blocking of any kind, that is why some of us are prepared to pay extra for these premium ISPs.

But my IP profile has dropped to 2000 from 3500 from this higher resync as a result What gives? It should be at 4000. Horrible 2mbit download speeds!

Does a BT Speedtest give you a 2meg download result, or is it actually much higher than 2 meg

[Steve]

AAISP according to their website limit the maximum throughput of a single  customer whilst in  their network to the BRAS limit, the upside of this,is that if suddenly 500MB/s say is heading to your IP address your connection will not get swamped. This I agree is entirely different to throttling as they are delivering the maximum throughput for your connection.


http://aaisp.net.uk/kb-broadband-shaping.html

[pctech]

I'd day that most ISPs match the speed that a customer's traffic is delivered to an edge router for onward transmission to a customer as firing data at 24 Meg when the customer has a profile of 5 might well lead to packet loss.

[Aaron]

Does a BT Speedtest give you a 2meg download result, or is it actually much higher than 2 meg

2meg download result as well. My downloads are only managing to max at 240 KB/sec, which is a 2000 profile.

Will call support on Monday if it's still like that, thanks Steve

[kinmel]

I have been doing a number of hourly disconnects followed by BT speedtests and now the BRAS profile changes instantly after each resync.

At this moment the  BT Speedtester is showing " IP Profile for your line is - 4308 Kbps" rather than moving in the old half meg increments.

[Rik]

It's certainly what I've seen, Alan. We apparently have a new rule book.