Not sure if it is possible but is there a facility to block certain numbers from being dialed from agents? We are currently being hit buy scam/fraudsters asking agents to them back ring back. We want to block these numbers.
Yes, I thought the option with prefix at trunk level as well, but it would be so tricky to maintain it. from my point of view is the GW level the best way how to achieve it. We implemented similiar function on Cisco GW too.