# Recommendation I.231.6 (11/1988): Circuit-mode bearer service categories : Circuit-mode 384 kbit/s unrestricted, 8 kHz structured bearer service

> superseded recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q27051393](https://www.wikidata.org/wiki/Q27051393)  
**Source**: https://4ort.xyz/entity/recommendation-i-231-6-11-1988-circuit-mode-bearer-service-categories-circuit-mode-384-kbit-s-unrestricted-8-khz-structured-bearer-service