Non Call Associated Temporary Signaling Connections (NCA TSC) are used to establish connections and pass messages for features like Message Waiting Indication (MWI) activation and deactivation. QSIG protocol establishes and releases the NCA TSC for each MWI session. When a TSC is established between two Communication Manager systems it sends the message it was established for. The TSC then stays up until there have been a few minutes of inactivity. Depending on traffic, this TSC can be used for multiple messages.
A TSC that is established between a Communication Manager system and a messaging system will be taken down after the initial message is sent.