G.INP

[Bill]

OpenReach briefing to ISPs: http://www.ispreview.co.uk/index.php/2015/04/bt-openreach-briefs-uk-fttc-fibre-broadband-isps-on-g-inp-issues.html

TBB thread with some discussion about it, I know no more than that.

[Bill]

Hmm... I read somewhere that G.INP will allow the DLM to be more responsive, ie it won't sit and sulk for several weeks after it (eg) puts interleaving on the line.

Looks like it might be working, this morning it gave me back the ~10msec of latency and 8-10Mbps of sync that it stole only about 30 hours ago!

[Gary]

Hmm... I read somewhere that G.INP will allow the DLM to be more responsive, ie it won't sit and sulk for several weeks after it (eg) puts interleaving on the line.

Looks like it might be working, this morning it gave me back the ~10msec of latency and 8-10Mbps of sync that it stole only about 30 hours ago!

You are lucky, the balls up that BTORT have made has seen people with ECI Modems and Huawei Cabs who run at full 80/20 drop down to 67 and latency as high in extreme cases as 50Ms. Since they installed ECI cabs there are now hundreds of thousands of people potentially on a two tier FTTC service due to BTOR's bean counters. THe ECI cabs were cheaper and could contain as many line cards as the Huawei 288 and also run at lower power, that's probably going to be reduced since they all need warning pads now as they let in to much moisture  ::)Glad your G.inp is working, just wish I had it and wasn't on a ECI cab. 

[Tech Dude]

I have a Draytek 2860n (FTTC) that's been sync'd @ around 52 to 54 MB for ages.

In February / March 2015 my sync rate dropped and latency increased on the back of a line fault. I thought that the DLM made some changes and that I'd have to wait for recovery. Sync rate dropped to mid 30's with latency going up. A reboot after waiting for days often resulted in an even lower sync rate.

I looked at various Draytek firmware revisions with G.INP support: 3.7.5 / 3.7.8 / 3.7.8.1 / recently released G.INP BETA which have improved my sync rate, reduced the latency BUT has introduced a host of issues (as listed below), resulting in me reloading a non G.INP version of firmware (listed a STANDARD, not with Vectoring / G.INP) on the Draytek site.

It seems that G.INP has been activated on my line (down stream only) when looking at the line stats with interleaving either set to Interleave or Fast, dependant on the firmware used during the test. I seem to also get different results when using the BT Wholesale Speed Tester using different firmware (with non G.INP reporting more than a 10+ MB drop in my profile in minutes which I can restore with other firmware.

Results of testing (G.INP / Vectoring firmware:

1. Sync rate recovers significantly (although not holding a stable connection for some firmware with frequent re-syncs)
2. Latency drops (with limited / no packet loss)
3. HTTP traffic is highly erratic (browsing both faster / slower with frequent stalls, not functional - as if name resolution & routing stops working)
4. POP3 protocol fails, STMP seems to work
5. Vodafone Sure Signal (Alcatel Lucent 9361 FEMTO/3G signal booster) is NO LONGER able to establish an outbound connection to a remote host / does not connect using the G.INP firmware which also provides support for Vectoring).
6. Some delays in establishing other outbound VPN services (I have tested with VPN capabilities disables as well)

I'm having to run non G.INP firmware on a G.INP enabled line - running slower with increased latency. Maybe a day run without a re-sync will help, maybe not ?

Any advice or suggestions will be greatly appreciated !

Thank you.