- Fix: AOC-D unit information length was set to 1 despite its actual length
- Removed optional BillingID from AOC-E data
- Cross-checked AOC-D and AOC-E IEs to other systems (Audiocodes Mediant 800; traces found in public sources)
- Tested with ISDN TEs: Siemens Profiset 51, T-Concept P522, Philips SOPHO ErgoLine, sphairon NT1PLUS-split; K1297 ISDN protocol tester