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News Faster service on 21CN lines

December 2011 It seems there are a couple of things happening that mean almost all of our 21CN customers will get slightly more speed!

We don't have any briefings from BT on this yet, but various investigations have suggested some things are changing now.

If we get more concrete information from BT on this, I'll update this news page.

FTTC frequency plan changes

It seems there has been a frequency plan change involving the VDSL links used for FTTC. This seems to be a prelude to trials of 80M FTTC services soon. We don't have any more details to publish on the 80M trials, but like some other ISPs we are on the trial. What is interesting is the frequency plan changes that are happening or have happened appear to be improving the sync speed of normal FTTC customers on the normal 40M services. The result is many more are now able to get the full 40M or at least a few meg more than before.

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.

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