A document that regulates security-relevant aspects of an intended connection between an agency and an external system. It regulates the security interface between any two systems operating under two different distinct authorities. It includes a variety of descriptive, technical, procedural, and planning information. It is usually preceded by a formal MOA/MOU that defines high- level roles and responsibilities in management of a cross-domain connection.
Sources:
CNSSI 4009-2015
A document specifying information security requirements for system interconnections, including the security requirements expected for the impact level of the information being exchanged for all participating systems.
Sources:
NIST SP 800-47 Rev. 1
under interconnection security agreement