As there a many permutations on how this could be done it’s not really feasible to have a document that outlines this.
For us to be able to help you out please start by describing your specific setup, including what type of connection you have with your service provider, what control protocol you use for your voice gateway, how your service provider sends called, for the fact also calling, numbers to you, if you do any number manipulation, if you do where do you do it, if your number manipulation is in your gateway or in CM, if in CM what type of configuration element(s) do you use for the number manipulation?
As you can tell there are many options for how to set this up.
There won’t be a specific document where it explains how to use the new DID range. As @Roger Kallberg mentioned we need more informations regarding your setup. so that we can provide you suggestion how it can be done.
