| In force components | 
| Number 
 | Title | Status | 
| Q.933 (02/03) 
 | ISDN Digital Subscriber Signalling System No. 1 (DSS1) - Signalling  specifications for frame mode switched and permanent virtual connection control and status monitoring 
 | In force 
 | 
| 
 | 
| Superseded and Withdrawn components | 
| Number 
 | Title | Status | 
| Q.933 (03/93) 
 | Digital Subscriber Signalling System No. 1 (DSS1) - Signalling  specification for frame mode basic call control | Superseded 
 | 
| Q.933 (10/95) 
 | Digital Subscriber Signalling System No. 1 (DSS1) - Signalling  specifications for frame mode switched and permanent virtual connection control and status monitoring | Superseded 
 |