Thanks, CarlT. I have probably forgotten most of what I knew about those devices.
I really don't know why j0hn makes a reference to vectoring. 
As the capacity of the MA5616 was being discussed?
OpenReach run them up to 256 ports with HD extension, but the line cards on the smaller Huawei cabinets only do vectoring on the 32 port cards last time I checked, limiting them to 128 ports.
With regards to Huawei MA5616's...
OpenReach have 256 port versions live in the network.
OpenReach have 128 ports vectored live in the network.
