"Non-exchange-based diversion services" is where a specialist company working in association with the carrier offers an enhancement to the ability to divert ISDN30 connectivity in case of failure to any other number or group of numbers.
"Inbound numbers", or "08 type services", is where the carriers or specialist companies can offer 08/05/03 prefixed numbers to the ISDN30 direct dial telephone numbers and can point them to alternative numbers in the event of a diversion requirement.