well you said "Where does that 98% come from? I don't remember seeing it anywhere." and I provided some information from a SIN which would go some way towards explaining that, for the benefit of anyone reading. Even you, if you wanted to.

Do you have a problem with that ?

In reply to a post by yarwell:

Openreach docs all work in line rates, profiles are an upstream responsibility.

So you're unaware that the Openreach DLM sets a profile?

I am aware that the Openreach DLM has a sync speed profile for the line which reflects the product chosen and the DLM can adjust it by applying a band which from memory has a minimum 50% of the max to avoid syncing at silly low speeds.

That's a line speed thing. It isn't an IP Profile. The IP profile is downstream shaping set by the CP in response to the speed updates that are inserted by Openreach into the PPP / DHCP negotiations.

In reply to a post by yarwell:

words, and for some reason I can't find them on the page linked ?.

Sorry . I scrolled down that page to here:-

Data Rate (bRAS profile)

The Data Rate is the fastest speed (throughput) that you will be able to download at and is profiled by BT at the bRAS.
A maximum throughput level is needed to stop more data than your line can physically achieve being sent down the backhaul and being dropped at the DSLAM.

For more information see bRAS / IP profile page.

I followed that link and my quote is from way down that page.

In reply to a post by yarwell:

I am aware that the Openreach DLM has a sync speed profile for the line which reflects the product chosen and the DLM can adjust it by applying a band which from memory has a minimum 50% of the max to avoid syncing at silly low speeds.

That's a line speed thing. It isn't an IP Profile.

So the Openreach profile is a line speed profile not an IP profile? is this line speed profile the sync speed or 98% of the sync speed?

In reply to a post by yarwell:

... in response to the speed updates that are inserted by Openreach into the PPP / DHCP negotiations.

seems slightly at variance with

In reply to a post by yarwell:

DLM is only concerned with the Line and the VDSL connection over it, it has no knowledge of the PPP

I know what you meant to say, but will the OP? Your cleverness can be very confusing.

In reply to a post by yarwell:

It's clear from the diagram that the BRAS is not the DLM system, but merely a consequence of the sync speed which itself is a consequence of the DLM system. Note the one way arrow. BRAS profile is a dependency of DLM via the sync speed.

1) The IP Profile is merely one parameter within the BRAS profile.

2) This thread is about FTTC connections. It is clear that diagram is discussing ADSL Max, with possible adaptations for WBC in the accompanying text. The DLM described there has nothing(directly) to do with the determination of sync speed on FTTC.

3) Given that the Kitz articles are describing BT Wholesale line control systems, they seem to be quite clear that the setting of the IP Profile at the BRAS is controlled by the BTW DLM.

I've no idea why anyone would want to conflate the line management and IP profiling into one thing when they are a) different functionalities and b) different systems

I have no idea why you should try to show that only one DLM is active when the evidence you yourself provide points to there being two, as originally stated.

So the Openreach profile is a line speed profile not an IP profile?

Absolutely. That's the only reference to profile in Openreach's domain that I can see. It's Generic Ethernet Access after all.

is this line speed profile the sync speed or 98% of the sync speed?

Openreach generally work in data rates, as per the SIN excerpt I posted earlier. So I expect it is set as a data rate but I don't know if the DSLAM is given a sync speed to work to or a data rate - do you ? The outcome would be the same.

In reply to a post by RobertoS:

Where does that 98% come from? I don't remember seeing it anywhere.

I meant 96.79% I think. Did I mention I was confused?

I wonder where the calculation of "IP profile = Sync speed * 96.79%" is done?

In reply to a post by yarwell:

Openreach generally work in data rates, as per the SIN excerpt I posted earlier. So I expect it is set as a data rate but I don't know if the DSLAM is given a sync speed to work to or a data rate - do you ? The outcome would be the same.

No I don't, but I suspect it's sync speed.

Maybe one way to find out would be to determine if the "IP profile" or equivalent for Sky matches the sync speed of an unlocked modem or is 96.79% of the sync?

Edited by deleted (Wed 13-Feb-13 18:48:58)