German FTZ ISDN Specifications » History » Version 1
laforge, 02/02/2022 09:16 PM
| 1 | 1 | laforge | h1. German FTZ ISDN Specifications |
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| 3 | 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. |
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| 5 | In case of ISDN, the specifications mainly describe differences to the ITU-T specifications like I.430, Q.921, Q.931 and others. |
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| 7 | 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. |
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| 9 | 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. |
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| 12 | You can find a collection of such specifications at https://people.osmocom.org/laforge/ftz/ |
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| 14 | h2. National ISDN (1TR6) |
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| 16 | TBD |
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| 18 | h2. Euro-ISDN (DSS1) |
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| 20 | TBD |
