This Recommendation describes the frame relay network-to-network interface intended for the interconnection of public networks providing PVC and/or SVC frame relay data transmission service. The signalling at the NNI for frame relay SVC is applicable to public data networks supporting ITU-T Rec. X.36 at the DTE/DCE interface. Details of physical layer, data transfer and signalling procedures for SVC and PVC at the network-to-network interface are defined. PVC signalling procedures have been enhanced with a new segmentation capability procedure to increase the number of PVC status reports.

Recognizing that frame relay bearer services and signalling are not supported by ISDN local exchanges, Case B has been removed from ITU-T Rec. Q.933 (2003). Consequently this version of ITU-T Rec. X.76 no longer supports the NNI signalling capabilities specific to ITU-T Rec. Q.933 (1995) Case B.

This revision replaces ITU-T Rec. X.76 (2000). This revised ITU-T Rec. X.76 (2003) is in alignment with the latest release of ITU-T Recs Q.933 (2003) and X.36 (2003).