(Non-Facility Associated Signaling): When a group of PRI interfaces are effectively bundled together, one D-channel can be used for the signaling data of all the combined B-channels, while the redundant D-channels can be used for data transmission. NFAS is only possible with a T1 PRI.

stands for Non-Facility Associated Signaling. For NFAS configuration, a single CCS component instance provides the signaling for multiple E-1 or T-1 lines, providing an extra B channel for those lines without a CCS subcomponent instance; this means that only the CCS instances providing the NFAS signaling will need to be created. The decision to use a NFAS configuration occurs at the time of component-instance configuration, not during component configuration, meaning that only the number of CCS instances required needs determination prior to component initialization.

Edit / See: Non-facility Associated Signaling