Aha! There's an article all about it here http://www.kitz.co.uk/adsl/ginp-retransmission.htm

and what does it say

As you note above, to comply with SIN 498, modems and routers must support retransmission in the downstream, but it is not a mandatory requirement in the upstream. Taking this into account and to maintain a high level of service, when we first rolled out retransmission to our Huawei estate we introduced interleaving on all lines where the modem/routers did not support retransmission in the upstream.

Are you seriously suggesting that the ECI modems and HH5A and Plusnet Hub One don't meet the requirements of SIN 498

In reply to a post by Oldjim:

Are you seriously suggesting that the ECI modems and HH5A and Plusnet Hub One don't meet the requirements of SIN 498

Yes. I haven't seen anywhere stating they do.

So BT provided a modem which doesn't meet their own standard and hence isn't an accepted device -

That appears to be the situation. Also Openreach appears to install modems that don't either.

I'm not sure. But I've just found one on the Plusnet forums that confirms they let customers see the GEA test results.

Later on the customer posts an image, but my machine has just started playing up so can't get the link.

Edit - no use re G.INP - it looks like an ADSL2+ circuit.

Edited by RobertoS (Tue 12-Jan-16 14:20:42)

The particular image (this one I think) doesn't show retransmission (it's a non-G.INP line with interleaving on): http://community.plus.net/forum/index.php?action=dla...

The GEA test will show interleaving, retransmission or error correction off for each of the upstream and downstream on the profile name, it can only show retransmission if the device supports G.INP. Interleaving and retransmission can show (AFAIK) low or high

Edited by deleted (Tue 12-Jan-16 15:04:01)

In reply to a post by Al1264:

To demonstrate whether a device supports G.INP if it doesn't report it I'd have thought asking the ISP for a GEA test should confirm whether retransmission is for downstream, upstream or both, 'Retransmission' on a GEA test confirms active G.INP in the relevant direction.
I'd imagine a few users will, by now, have seen such test reports indicating retransmission active downstream with HH5A

I see no-one has posted the results of a GEA test showing the Homehub5A or Hub1 running with G.INP. My feeling is that this device doesn't work with G.INP enabled.

G.INP wasn't part of the SIN478 when FTTC was first rolled out so the modems weren't required to support it back then.

However SIN 498 required it on downstream from at least Sept 2014 (v6) (I haven't found an earlier one) but other references indicate that it was introduced as early as August 2013 from http://www.niccstandards.org.uk/files/current/ND1436... and since BT were still providing the ECI modems after that time surely they should have supported downstream retransmission

Edited by deleted (Tue 26-Jan-16 19:14:00)