To generate an STC license you need the following information:
Then follow the steps below:
1. Connect to the Spirent Customer Service Center website at: http://support.spirent.com
2. Locate and click on License Activation (top right corner of page)
3. Enter the Entitlement ID/LAC as shown on your agreement and click Log In.
4. Follow the prompts to activate your license(s).
See also page 64 in Getting Started with Spirent TestCenter.(which can be found at the Spirent CSC download site under related resources for the Spirent TestCenter Application)