# Recommendation Q.920 (11/1988): ISDN user-network interface data link layer - General aspects

> superseded recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q27051436](https://www.wikidata.org/wiki/Q27051436)  
**Source**: https://4ort.xyz/entity/recommendation-q-920-11-1988-isdn-user-network-interface-data-link-layer-general-aspects