"AT&T Integrated Services Digital Network (ISDN) Primary Rate Interface and Special Application Specification User-Network Interface Description"; Jul. 1989. |
"AT&T Integrated Services Digital Network (ISDN) Primary Rate Interface Specification", Jul. 1989. |
"ISDN: Concepts, Facilities, and Services", Gary C. Kessler Copyright 1990 McGraw Hill Inc, pp. 125-144, Appendix C. |
Northern Telecom Primary Rate Interface Doc. No. NIS A211-1 of Jan., 1992 (Section E. p. E-32). |
British Telecom Doc. No. 188 of Sep. 1984 entitled "Digital Private Network Signalling System" No. 1 (DPNSS 1) (BTNR 188), (Sec. 11, pp. 4-6,22-24)(Sec. 19, pp. 1-12). |