In this chapter we saw what to look for when making commercial choices about our upstream and downstream providers.
What is the mission of an ITSP? What kind of services do they sell? What technologies are involved in their operation? What should we be aware of? What questions should we ask? What are the hints that tell the good from the bad ones, and the features that define the one that is right for us?
We understood the differences between white and black routes to international destinations, their different pricing, reliability, quality. Then we saw the same with DID (DDI), the phone numbers we want people to call in order to reach us.
We closed the chapter with a reasoned laundry list of other features that can greatly affect our experience as Service Provider Customers.
