N3 Migration Process

Hi All

We are currently involved in a N2 (Healthnet) to N3 migration. I have
read all the websites but still cannot make heads or tails of the
actual process. Could someone possibly assist with:

1. The roles/responsibilities of BT
2. The roles/responsibilities of the client

Also, any advice on the actual migration ("do's and Don'ts) would be
greatly appreciated. The websites seem to be a bit thin on Techie
stuff. I am currently running on the assumption that if all is working
on N2, then it should just be a case of cutting across and allowing the
new routes to propogate. Is this correct?

Regards

Deanbo