You are quite right. C&W are not new to ADSL2+ in themselves

To my knowledge, Bulldog didn't use SRA either

I have heard stories such as they require a firmware update and that firmware update is too expensive, never before have I heard a reason for not applying 'software' updates is due to cost

that's because as usual you're talking out of your behind with no real knowledge of the industry.
And to back that up we have this fantastic example:

Given SRA is something that is going to benefit longer lines more than shorter lines we can see where the isp's priorities lie, in giving the best performance to the shortest lines.

While I haven't looked at it (but probably will) it's reasonable to assume that SRA is part of this standard.

From memory I think it's actually part of ADSL2, not 2plus.

Therefore if a DSLAM doesn't support SRA then it doesn't conform to the standard

It's not usually as black and white as that. IEEE standards do tend to be more strict, but RFCs for example are very specific about the use of words such as "shall" and "must". So with RFCs at least you can be compliant with it but not implement everything that is contained within it. The same *probably* holds for IEEE standards.

So are Be* suggesting that they've purchased/installed equipment which doesn't meet the standard it's supposed to meet?

Who says it has to meet that?
All BT require is that any equipment used is within the ANFP (Network Frequency Plan), it's perfectly possible to support a subset of a standard and be within BTs idea of what is acceptable and of course what is acceptable to a Service Provider.

as Be dish out routers with their service one would think they could come up with a DSLAM / router combination that gave the best outcome.

I can imagine there are interoperability issues with SRA just like some routers will do 8128 interleaved on BT and others won't. How much of this is down to features under the user's control I don't know either - the ability to cap speeds, tweak SNR margins and select useful features are often hidden and have to be invoked from the CLI.

In reply to a post by nredwood:

I'd be surprised if SRA was enabled. As far as I'm aware no UK ADSL2+ provider is using it officially. UKOnline will do it, but it's not officially supported
C&W are however new into this, so who knows

Connection's stayed up for 2 days now, but sync rate firmly stuck at 2635/959 and SNR Margin wandering around between 8 and 12dB.

So, no SRA (and what was going on initially is anyone's guess.)

I suspect the alternative modem firmware is somehow hanging on better when noise levels increase, but I'm also not seeing a drop/reconnect at higher speed when it falls.

Demon asked to provide MAC. They say they'll email it 'within 24 hours'.

Out of the lines that we provide via C&W, we are always told that SRA is not currently possible when we get a request from a customer.

Would certainly be nice if they did offer it though.

Matt

Thanks for that confirmation, Matt

Which ISP are you migrating to, if you don't mind me asking?

In reply to a post by nredwood:

Which ISP are you migrating to, if you don't mind me asking?

CCS Leeds (Business 15), I believe they're an Entanet reseller and yes, I have read of the recent problems some customers have had with Entanet.

In spite of that, it still looks like they're better now than Demon are now and I'll be paying slightly less. Being pragmatic, both they and BT have been rolling out major upgrades. There are bound to be problems. I'll give them the benefit of the doubt.

Interesting...

I've just had someone from Demon call me. It seems like they read this forum...

He's going to try to get C&W to enable SRA and failing that, try to get us reconnected back to BT with their rate adaptation (which they told me was impossible last week.)

I've known this line is rubbish from when we moved here in 2001. Noise levels (probably crosstalk) vary during the day and seasonally (high rainfall correlates with low sync rate.) It's been suggested that the cable dates from the 1940s, when our estate was built, and water's getting in.

So it stands to reason that we need some form of rate adaptation in order to maintain a stable connection. SRA would be ideal if it worked. It strikes me that our line problems are exactly what SRA is designed to deal with.

BT's profiling worked, though obviously responds rather slowly to changing line conditions.

Capping the line at the maximum rate possible under the worst conditions wouldn't be acceptable as we'd probably end up with 1M fixed; not too good when I've seen 3M on ADSL during a long dry spell.

Wouldn't it be nice if one ISP or another at least trialled SRA with a few customers? For people like me on long-ish lines (54dB Att.) with variable noise it'd theoretically provide a stable connection; one that adapted to changes more rapidly than BT's profiling allows.

I gather Be* won't take on customers with poor/long lines... I wonder if they've considered that enabling SRA would mean they could take on these customers; and that might more than pay for their firmware upgrades...

Let's see what happens. I haven't firmly decided to migrate quite yet, but if it's the only way to get a stable connection with some form of rate adaptation then there's little choice.