The IP Profile is nothing to do with the Openreach DLM. It is a feature of the WBC one. Proven by there being no IP Profile on TT and Sky FTTC.

WBC also has options for the ISP to specify Standard, Stable, or Super Stable per connection. Whether there is any mechanism not known about in the public domain to pass this request to the OR one I don't know. If there is, it will probably be documented in the WBC FTTC handbook, only available to ISPs. The most likely option is that it triggers line profile banding. That is certainly present in the OR DLM. Note that the line profile is not the same thing as the IP Profile.

There is no "semi" about the IP Profile automatically following the sync. What can go wrong is that the re-sync is not detected by either WBC or the ISP, (still to be resolved), due to exceptionally quick resyncs completing without the PPP/DHCP spotting the line drop. This also happens occasionally on ADSLx. See this detailed post. Both quotes are from the OR description of their DLM.

I'm not sure where you get your information about "DLM is super-keen on stability". Which of these DLMs? I've seen no evidence here of this on FTTC.

The fact remains that the severe criticism of the BT DLMs by zyborg is based on a product that is not used on FTTC. Until I and others told him, he didn't even know that lousy old product could be avoided by going LLU - and as I said it was a mammoth task to persuade him to take that step.

The new WBC product is radically different and better. The OR one he knows nothing about from his own experience.

They 100% offer 80/20

It's offered on their website. Here's a screenshot.
http://i47.tinypic.com/11c8ql5.png

There's a number to call etc too. It's totally unlimited with no restrictions on vpn, p2p, torrents etc.

Here's a speedtest I just did. It's via wifi using the sky router so would be better via ethernet no doubt http://www.speedtest.net/result/2195361751.png

I agree with much of what RobertoS says; in particular that extreme criticism is mostly unfounded. As we both say; the main issue for a customer is DLM, not profile. TT and Sky share the DLM.

The rest is a matter of use of words. 'Semi-atuomatic' seems reasonable term for something automatic that doesn't always work without manual intervention. (In my experience, doesn't usually work without manual intervention, for the reasons he explains.)

The IP profile is 'to do with' DLM because of the way they are linked, even though they are operated by different sub-companies of BT in different locations. And for a typical Infinity customer with locked modem, the IP profile is the only indication (a rather poor one alas) of what the sync speed is, and thus their only guide to how DLM is behaving.

DLM does indeed have three control options, but as I said, the Infinity user isn't allowed to play with them. I'm not sure of the situation for other isps. The one used by BT retail means that a burst of noise can force the DLM settings down quite far and very fast. It will not build up again for a long time, often nearly two weeks; even if the line remains consistently good quality and capable of reliably returning to the original speed. That's what I mean by "DLM is super-keen on stability"; it is my experience confirmed by that of many others on the BT forums. Many people would happily turn off interleaving and choose faster speeds even if it did mean more error packets and more frequent loss of service.

I'm not sure you aren't mixing up the two DLMs, and also the behaviour on ADSLx and FTTC (Infinity if on BT Retail) . It would help greatly if you would say which you mean each time you mention DLM. Also when you say a burst of noise can force the DLM settings down quite far and very fast, I repeat I don't recall anything about this being mentioned as a general problem on FTTC.

You also seem, if talking about ADSLx, which we shouldn't be, to be conflating noise margin issues and IP Profile changes.

It may be me, but I feel befogged by your last two posts. Other than a few problems, unsurpising given the number of people on Infinity and other FTTC connections, there seem to me to be virtually no problems with either DLM. Just fault handling by support teams, and the need at times for an Openreach removal of unnecessary banding. Not seen any of those for a while either.

I was talking only about FTTC, not at all about ADSL. Sorry, I should have made that clear.

eg DLM at the cabinet. And if you look on the BT forum, you will see lots of complaints about it.

It is often confused with the profile on that forum. As I mentioned, people can see the profile but can't see the DLM controls so the confusion is natural. Quite a few of the complaints are actually ungrounded, or come down to issues with the HomeHub. However, a significant number remain that are to do with DLM. Maybe a single burst of noise is an exaggeration, but a not very long extended burst will push down the DLM allowed rate (not sure what term is used for it); and I and many others have seen it take around 2 weeks to return.

I assume you mean an inhouse BT forum?

Anyway, I believe the normal term for it is banding, where a maximum and minimum sync are set. I expect this is the topic more fully described in the WBC FTTC Handbook. I also think this mechanism is how the higher stability options are achieved, instead of the ADSLx BTW DLM's control by the target noise margin.

Yes. Anyone thinking of infinity should visit it. http://community.bt.com/t5/BT-Infinity/bd-p/BTInfinity No need to be on bt to sign up.

~~~ sorry for the bad link earlier, should work now

Edited by StephenTodd (Sun 23-Sep-12 11:14:55)

Post deleted by BatBoy

In reply to a post by StephenTodd:

Yes. Anyone thinking of infinity should visit it.

But you run the risk of really inexperienced/uninformed people posting "stuff" 24x7 that can give a false impression. I've seen the same on other ISP forums that are open to the public. tbb's big advantage is clued up individuals (e.g. RobertoS and others) and the likes of MrSaffron.

The BE forum avoided the problem by limiting to members, it kinda makes sense now.

Yes, I absolutely agree with the problems of a forum like the BT one. I should have put that as a caveat on my post. However, read carefully, it does give a lot of insight that complements TBB. Even the BE and TBB forums (and everything else on the web) contain a fair proportion of rubbish and need to be interpreted carefully.