CCITT Rec. X.10 (11/1988) – CATEGORIES OF ACCESS FOR DATA TERMINAL EQUIPMENT (DTE) TO PUBLIC DATA TRANSMISSION SERVICES
1 Scope
2 General
3 Categories of access
3.1 Direct connection to data transmission services provided by public data networks
3.2 Switched connection to data transmission services provided by public data networks
3.3 Direct connection to data transmission services provided by ISDNs (including through Terminal Adaptors)
3.4 Switched connection to data transmission services provided by ISDNs (including through Terminal Adaptors)