Tweaks for ECI VDSL2 cabinets may boost speeds for some
The manufacturer of the DSLAM within the VDSL2 cabinet is not something any of us get to choose and our forums have had people reporting the success of various initiatives on Huawei cabinets such as G.INP and the xdB roll-out that have boosted their speeds particularly the download speed.
The last few days has seen Openreach announce that xdB noise margins are to be run through a proof of concept trial on ECI cabinets (oddly one or two claim to have already seen this in their modem stats, but the wider data set suggests that nothing major has taken place yet). xdB for those not aware means that rather than the VDSL2 modem syncing at a 6dB noise margin, if the Dynamic Line Management system believes the line is stable at a 6dB target noise margin a setting of 5dB will be applied giving you a little more speed, and then after a while if that is stable a target of 4dB is tested and then 3dB. This can give people a few more Meg of speed, but for those at the maximum sync speed e.g. 39999Kbps for 40/2 and 40/10 products, and 79999 Kbps for 80/20 nothing will change. The reduction in target noise margin is not permanent and if the DLM sees enough errrors it will return you to a higher target noise margin.
The result of the xDB and G.INP improvements (note ECI is not getting G.INP yet - this impulse noise protection algorithm can boost speeds too) is pretty obvious when you look at how the speeds of FTTC users on ECI and Huawei cabinets has changed since 2015. While a gap of 3 Mbps may not sound much, for users in the 20 to 25 Mbps region it can be the difference between ultra HD video streaming smoothly or seeing the buffer symbol of doom every few minutes. For users with sub superfast speeds in the 5 to 8 Mbps, even an extra 1 Mbps might be enough to make HD video streaming smooth and while the obsessive may not the change in large file download times the quality and speed of broadband is very often judged by the majority based on how well video streaming performs. The chart plots the median speed, but the mean average shows a similar pattern and has a 2.1 Mbps difference in Q2 2017.
ECI cabinets represent around 30% of the 82,000 VDSL2 cabinets (this figure does not include additional second cabinets added to increase capacity) and were largely rolled due the earlier commercial phases, almost all the BDUK project cabinets are Huawei based and with the longer line lengths you would expect as your edge into the peri-urban and rural areas the difference between the two sets of median speeds is even more suprising.