Asterisk network Interconnect

Does anyone have any info on the status of the various system interconnect options (Sip direct to another provider). At one time there was freenum,org and E164,org, both of which seem to be dead. Something called has recently appeared (using blockchain tech) There was also sipbroker, which I am not sure where it is at the moment. Then there was Dundi. Don’t know what is going on there. And I thins something called ISN. Anybody that has any info on any of these or any other mehtod of totally bypassing the Bell system for calls?