# Recommendation X.31 (11/1988): Support of packet mode terminal equipment by an ISDN

> superseded recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q26985489](https://www.wikidata.org/wiki/Q26985489)  
**Source**: https://4ort.xyz/entity/recommendation-x-31-11-1988-support-of-packet-mode-terminal-equipment-by-an-isdn