What is the best migration method in this scenario:
The customer has existing T1 line to their old PBX. They have 100 DID numbers. We will be migrating them to CallManager and Unity/Exchange. There will be two new VG200 connecting to two new ISDN PRI's. They will get 140 DID numbers with 100 of them same as what they currently have. There will be no need for legacy integration. It will have to be a weekend cutover. I would like to have both connection( i.e. the old T1 and new PRI's) running for a period of 1 week for pilot test. Knowing that 100 of the 140 DID's are the same, will it be possible to have both systems running for pilot?
What's your experience and recommendations for this type of migration? any case study for this type of migration scenario?
Thanks!
Chris