ABSTRACT: This document proposes the Generic Requirements for local switching systems that offer public network ISDN capabilities over a Primary Rate interface to CLASS II equipment. The scope of the document is to call establishment and clearing procedures for signaling over a Primary Rate Interface to CLASS II equipment and interworking with existing networks. Supplementary services over a Primary Rate Interface are beyond the scope of this document. In addition, four appendices are included covering the following material:

• Appendix A
Covers Symmetric Call Operation for public switching systems providing private network services;
• Appendix B
Covers the D-channel Back-Up procedures to allow a public switch to have a standby D-channel to allow greater reliability when using non-facility-associated signaling (for more than 2 DS1 facilities);
• Appendix C
Covers the Data Dictionary for memory update commands;
• Appendix D
Covers the Group-Specific Traffic application for Primary Rate to allow CLASS II equipment increased public and private traffic functionality..

TR-NWT-001268 replaced TA-NWT-001268 and SR-NWT-002108. TR-NWT-001268 is erroneously referred to as "TR-NWT-001286" in GR-505. Issue 1 contains Revisions 1 through 4.