| ISUP
(Integrated Services User Part) |
| Essential
for circuit-switching related signalling |
| Not only
ISDN (can be generally used in PSTN) |
|
|
|
|
|
| Features: |
||||
| Establishment /
release of circuit switched connections |
||||
| (basic call control) using link-by-link signalling |
||||
| End-to-end
signalling between two exchanges (for this |
||||
| purpose SCCP +
ISUP is used) |
||||
| General
(non-user-related) circuit management |
||||