# Recommendation I.241.1 (11/1988): Teleservices supported by an ISDN: Telephony

> recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q26985358](https://www.wikidata.org/wiki/Q26985358)  
**Source**: https://4ort.xyz/entity/recommendation-i-241-1-11-1988-teleservices-supported-by-an-isdn-telephony