swapping out some DSLAMs, unless there's some other way to get even more ports into the existing ones
TBH I don't think viability of the MA5616's is much more than of the M41's when it comes to upgrades. * But at least the Huaweis have g.inp and thus 3dB. However it's looking like most of the latest technology could be confined to the MA5603's
There's quite a bit more to making them vectoring enabled than just adding the cage. For starters the existing Central Control Unit Board would need upgrading from a CCUB to a CCUE (more specifically a H831CCUE) to be able to support daughter cards. (to attach a vectoring module to).
The backplane doesn't appear to be able to support this either and _would_ need upgrading from a H831MABA -> H831MABB. You'd also need to swap out the power board with one with higher wattage to be able to add the daughter card (200W -> 400W). There's about only the chassis, fan tray and service board that wouldn't need an upgrade.
I'm even doubtful about those if they were to have vectoring as the line cards would also without need replacing so not sure how that would affect the system board. Finally the real bummer.. because of heat dissipation if you add a vectoring module, then the MA5616's are restricted to just 96 lines (compared to the current max of 128) which could in itself cause headaches for Openreach unless they housed it in a larger S200 **.
Hopefully SRA won't be as drastic as vectoring when it comes to the MA5616's. But it shows that the smaller Huawei cabs are not without their problems either.
TBH it would probably work out cheaper for Openreach to upgrade the M41's to V41's than it would be to fully upgrade the MA5616's. Yeah you can add a vectoring module in a cage.. but when the rest of the boards also would need upgrading to support the daughter board, but the time you paid someone to rebuild the MA5616's in the field then it probably works out as cheap to just buy a new [fully complete] dslam. Which is the point I was trying to make when it came to cost for Openreach. If OR arent willing to swap out the ECI's then I strongly doubt they will practically rebuild the 5616's by replacing most of the boards in field. I don't think I was getting my point across too well about just how much needs replacing in the 5616's before you can start adding daughter boards.
It only appears to be the MA5603's which are easily upgradable.. which is probably why they are the units which OR is installing most of these days.
*Yes they are upgradable, but if would require swapping out practically everything else in the MSAN
** At which point M41 -> V41 swapout is certainly easier than rebuilding the 5616's.