All of the DSLAMs on the commercial rollout are ECI 128 cabs. Are they capable of vectoring? Seems like there is a bit of an undiscovered problem here.
These ECIs are board-level
) vectoring-capable, after firmware upgrade. But not system-level
vectoring is very limited. To work even half efficiently, the subscriber lines in a particular cable bundle or binder - where they crosstalk with each other - must all be lifted-and-shifted to one linecard in the DSLAM.
That is because the ECI's vectoring engine is embedded in the firmware of the card itself, rather than in the DSLAM controller unit. The latter - where the DSLAM controller unit mitigates crosstalk between ports on different linecards - is known as system-level
At first glance it might seem possible, if inconvenient, to do that lift-and-shift of every subscriber line to make board-level
vectoring work. However, the distribution of lines across multiple binders - with different binder sizes, different take-up rates for lines in each binder, and whatnot - rarely makes that possible.
The next problem with vectoring, is that Openreach has started to 'cascade' DSLAMs in the street. When one DSLAM reaches capacity, another DSLAM is added in an adjacent cabinet. Which means that crosstalk is potentially spread across two (or more) separate DSLAMs. And that requires node-level
vectoring. The Huaweis (can) support this, but so far as I know, the ECIs cannot.
Maybe vectoring algorithms will continue to improve - but a lot of people could be disappointed to find vectoring isn't the panacea they'd hoped. It probably won't return their DSL performance to its original (pre-crosstalk) state. Could be wrong though. Hopefully!
Edited by edwincluck (Sun 15-Mar-15 19:40:38)