The required dual homed DISN Core or NIPRNet access circuits DO NOT follow geographically diverse paths from the CER(s) along the entire route to the geographically diverse SDNs.

In previous requirements we discussed the need for redundant DISN Core access circuits between the enclave and the DISN SDNs. Another method for providing the greatest reliability and availability for DISN services is to provide redundancy in the network pathways between the customer site and the redundant DISN SDNs. The DISN core network is designed to be highly reliable and available in support of the DoD mission, the most vulnerable part of the network is the access circuit from the enclave to the core and the path it takes from the SDN to the customer’s site. Therefore redundant access circuits should be provisioned. Physical pathways for communications network access circuits are vulnerable to physical disruption from a variety of threats, both natural and man made. These threats range from storm damage (falling trees, floods, to being damaged or dug up by "the big yellow fiber-finder" (backhoe); to rampaging vehicles attacking utility poles; to malicious acts including war and terrorism. To overcome the physical threat, the redundant circuits should follow geographically diverse paths.