PBX call duration restriction related

[Panasonic KX-TDA] Conversation Features
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Extension-to-Trunk Call Duration:
If a call between an extension user and an outside party is established, the call duration can be restricted by a system timer selected for each trunk group (→ Extension-to-Trunk Call Duration [472]). Both parties will hear an alarm tone 15 seconds before the time-limit at five-second intervals. If the timer expires, the line will be disconnected.
COS programming determines to enable or disable this feature (→ Trunk Call Duration Limitation [502]). Whether this feature is applied to outgoing calls only or all calls (how?) is also programmable.