I agree that this should be offered as a option or at the very least the ISP should create a interface with openreach to change between the three profiles which dlm offers. The documentation of the 'speed' profile indicates that it forces fastpath but isps only use 'standard' as far as I know.
My experience with dlm upon upgrade was that sync at 76/20 was fine, throughput ~73/18 - however as I was getting a few crc errors dlm decides to cap at 60/20 AND apply interleaving at the same time. It's simply a horrible design, incremental changes should be made not a ~18% decrease cap and latency increase as a result of interleaving when there is no packet loss, disconnections or throughput issues on the line.
I agree. I'll miss this level of optionality that I got with BEThere. They had an interface that allowed you to set Interleaved/Fastpath and Noise Margin of 3dB, 6dB or 9dB. I chose Fastpath and most of the time 3dB as it gave me the best speeds and lowest ping due to Fastpath being chosen (Gaming Mode On). Obviously the reliability of a line has to be considered, but mine rarely dropped out and produced no more than around 2000-3000 CRC errors a day, connection itself seemed fast and reliable.
I just hope when I get Infinity for Business Option 2 installed on the 8th June that I don't find my gaming experience ruined (e.g. Interleaving gets switched on).
In reply to Flamey post I have already asked the question to the mods regarding DLM profiles so I'll post the answer here.
After a bit of fact finding we've put together the following explanation:
Line stability on all FTTC lines, including BT Retail BT Infinity lines, is achieved by the use of DLM. DLM is applied by Openreach, who offer CP's a choice of 3 profiles - Speed, Standard or Stable.
BT Retail purchases its FTTC service (BT infinity) via BT Wholesale, which is a customer of Openreach. BT Wholesale also offers its CP's a choice of 3 DLM profiles - Standard, Stable, and Superstable.
The mapping between the Wholesale and Openreach DLM profiles is:
BTW "Standard" = Openreach "Speed"
BTW "Stable" = Openreach "Standard"
BTW "Superstable" = Openreach "Stable"
The DLM policy which BT Retail consumes for BT Infinity is BT Wholesale's "Standard" DLM profile, which in turn consumes Openreach's "Speed" profile.
It is not possible for BT Retail to specify different DLM profiles on individual lines, since this process is entirely automated by BT Wholesale and Openreach.
Hopefully this clarifies things for you but if you have any other questions by all means email me back.
There's nothing you can do about it. Openreach won't turn it off. End of.
Actually Openreach will according to the DLM section on page 2 of this fact sheet http://www.openreach.co.uk/orpg/home/products/super-fastfibreaccess/fibretothecabinet/fttc/downloads... but for some reason BT Wholesale don't offer the option to their customers. Nothing really different but it is interesting that Openreach offer the option.
So there is an option to choose, but BT dont allow it , no doubt if BE ever release a fibre product they might allow it 🙂
I think fibre to the premises willl come faster than BT letting you choose what level of interleaving you want.