German FTZ ISDN Specifications » History » Revision 2
Revision 1 (laforge, 02/02/2022 09:16 PM) → Revision 2/7 (laforge, 02/03/2022 10:00 AM)
h1. German FTZ ISDN Specifications In Germany, the FTZ (Fernmeldetechnisches Zentralamt, part of the government monopoly _Deutsche Bundespost_) issued a series of technical recommendations (TR) related to all aspects of the telephony and ISDN network. In case of ISDN, the specifications mainly describe differences to the ITU-T specifications like I.430, Q.921, Q.931 and others. Originally, in the 1980ies, when interational standardization of ISDN was incomplete, those specifications defined a _national ISDN_ variant. It is basically a fork of early drafts of Q.921 and Q.931. Later on, in the 1990ies, they switched to Euro-ISDN, also called EDSS1. The differences to ITU-T and ETSI specs obviously were much smaller then. You can find a collection of such specifications at https://people.osmocom.org/laforge/ftz/ h2. National ISDN (1TR6) |_.Number|_.File|_.Title| |1 TR 6|"FTZ-1TR6.pdf":https://people.osmocom.org/laforge/ftz/FTZ-1TR6.pdf|Kennzeichenaustausch zwischen DIVO(ISDN)-Vermittluingsstellen und ISDN-Teilnehmereinrichtungen - ISDN D-Kanal-Protokoll - (Schicht 2 und 3)| TBD h2. Euro-ISDN (DSS1) TBD
