The Network Working Group was set up in January 1999 as an amalgamation of several other working groups which addressed network issues. These groups (Network Interconnection, Network Planning, Technical Interface, and Shared Costs Facilities) are now listed as Discontinued Groups. Documents revised/revisited after January 1999 may be found on the Network Working Group web pages; other documents will be found on the web pages of the original working groups.

As a result of the amalgamation, the filenames on some of the Network Working Group web pages are inconsistent. A document revised after January 1999 may still have the filename assigned to it by the original working group; thus the TIFS page, for example, has documents with filenames beginning NT (Network), NP (Network Planning), and TI (Technical Interface). For a detailed explanation of the naming convention, please refer to Appendix 10 of the Administrative Guidelines.