All of OSI stack used ASN.1 extensively, something that would have made building protocol implementations much easier than text-based IETF style. SNMP is, IIRC

All of OSI stack used ASN.1 extensively, something that would have made building protocol implementations much easier than text-based IETF style. SNMP is, IIRC, inspired by much more capable CMI which was part of OSI stack of protocols and is still used in some high end WAN network gear for monitoring and control (whereas "write" aspects of SNMP have mostly disappeared)