# Recommendation I.411 (11/1988): ISDN user-network interfaces - Reference configurations

> superseded recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q27051416](https://www.wikidata.org/wiki/Q27051416)  
**Source**: https://4ort.xyz/entity/recommendation-i-411-11-1988-isdn-user-network-interfaces-reference-configurations