Early Feedback from Openreach’s G.INP ECI Hybrid Fibre Trial

Some early feedback from Openreach’s (BT) latest trial of ReTransmission (ReTx / G.INP) technology on Fibre-to-the-Cabinet (FTTC / VDSL2) based broadband ISP lines, specifically those using the operator’s UK estate of ECI street cabinets, has shown improvements in service speed and latency times (ping).

G.INP (ITU G.998.4) is an error correction solution that is designed to help resolve spikes of Electromagnetic Interference (impulse noise), which can improve a line’s stability and thus performance. The introduction of this technology can, on some VDSL2 lines, even sometimes produce a small increase in performance.

As we’ve reported before. The feature is nothing new to Openreach and they’ve had better luck getting it to work on their larger estate of Huawei based cabinets, but sadly the same cannot be said for those using kit from ECI. Various past attempts have been made to get G.INP working on ECI and all have run into problems.

Last month we reported that Openreach were preparing to give G.INP / ReTx another try on their ECI estate with a new trial (here), which has now started to go live. The good news is that early feedback from a number of Plusnet’s customers appears to be very promising (here).

Summary of Early G.INP (ECI) Feedback

➛ “My downstream connection speed has jumped by around 7Mbps at the moment – interleaving was on prior to the resync and it is currently off [65742 downstream connection speed before resync, 72479 after].”

➛ “My connection resynced about an hour ago, g.inp is on. Got an extra 7 meg on the download and 1 meg on the upload and 0 FECS since compared to about 10k every 5 mins before. Also latency is 0.27ms rather than 8ms before”

➛ “Same here my router was interleaved at 58mbps last night, it’s now 64.8. My noise margin is 6.3 down and 6.1 up.”

➛ “Just to say like everyone else’s my line has jumped from 38meg to 44meg this morning and the ping is now sitting at 10-13ms from 19-20ms, so a nice little increase on my long line.”

➛ “I’m on a short ~149m line but my speed has increased by ~4Mbps and ping speeds reduced from ~12ms to 9.”

The results are good, although the key will be whether or not the upgrade causes any problems like we saw before (this may only become obvious once the trial expands). At present the plan seems to be to test this on up to around 100,000 lines via supporting ISPs (opt in). The trial itself is currently expected to run until around August 2020.

Success in this trial will be viewed primarily as a reduction in faults driven by an increase in stability and increase in speed. Assuming the results are as expected then the feature will remain enabled and deployed to their remaining ECI estate.