To change the class of service (COS) for an extension in a Panasonic PBX using TAPI, follow these steps:

1. Ensure the Panasonic TAPI driver is installed and configured.
2. Connect to the PBX system using a compatible TAPI application.
3. Access the extension settings through the TAPI interface.
4. Modify the COS parameter based on required permissions and restrictions.
5. Apply the changes and restart the extension if necessary.

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