CANC is an autonomous message transmitted by the NE to a user when a session established by that user is terminated because no messages were exchanged for a long period of time (a timeout). There is a default timeout period based on the user’s privilege/security level. Starting with Release 4.0, timeouts can be provisioned through CTC. Starting with Software Release 4.6, timeouts can be provisioned through TL1 with the SET-ATTR-SECUDFLT command. The default timeouts based on privilege/security level are:
- A Superuser [SUPER] has a timeout period of 15 minutes.
- A Provisioning [PROV] user has a timeout period of 30 minutes.
- A Maintenance [MAINT] user has a timeout period of 60 minutes.
- A Retrieve [RTRV] user has no timeout period.
When a timeout occurs, the corresponding port drops the session and the next session initiation at that port requires the regular login procedure.
The CANC message is only used to indicate that a session has been terminated because of a timeout. If a session is terminated for a different reason (for example, forced logout, loss of communication), the REPT EVT SESSION message is used.