SIP Trunk Providers UK: Costs, Setup and Switching
Most businesses don't shop for phone services often. Then a contract ends, or ISDN stops being a realistic option, and you have to understand a market you haven't looked at in years.
This article walks through what moving to SIP trunking actually involves: what it costs, what the migration looks like, and where projects tend to go wrong. It should help you ask sharper questions when you speak...