# Recommendation I.241.4 (11/1988): Teleservices supported by an ISDN: Mixed mode

> recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q26985361](https://www.wikidata.org/wiki/Q26985361)  
**Source**: https://4ort.xyz/entity/recommendation-i-241-4-11-1988-teleservices-supported-by-an-isdn-mixed-mode