What is Interconnect ?
When a new Company / CLEC starts a service, they have to build interconnect? service between all the telecom companies in that region.
If they DO NOT have Interconnect with all the providers, the Number of that Company MAY not be able to receive calls from the UN CONNECTED provider.
For Example the Telecom does not have interconnect with a Mobile operator ABC GSM, the users from ABC GSM will NOT be able to call this XYZ Telecom users/ Numbers.