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Avalanche: My license is installed correctly on the Spirent TestCenter. Why does the Avalanche Commander report a license error message when reserving a port, error: Reserve failed for ports x slot x at xx.xx.xx.xx?



  • Spirent Testcenter test modules on Avalanche Commander
  • CPU5002
  • CPU5003
  • MX test modules
  • CM test modules
  • EDM test modules




Prior to version 4.10 of the Avalanche Commander uses TCL to communication between application and the chassis.   

  1. Check TCL paths are set up correctly in the application.  If not the paths are incorrect, you will get a license error message similar to the example below: 
    •   Reserve failed for ports 5,6, slot 2 at
    •   Error reserving ports // //
    •   This chassis may be experiencing a problem with its license. 
    •   The license could either be missing or expired, or your SUPPORT_ENTITLEMENT may be out of date. 
  2. The TCL paths are specified in Avalanche Commander > Tools > Preferences > Spirent TestCenter:   
    •   Path to TCL Interpreter - C:\Program Files\Spirent Communications\Spirent TestCenter x.xx\TCL\bin\tclsh84.exe
    •   Path to Initialization Script -  C:\Program Files\Spirent Communications\Spirent TestCenter x.xx\Layer 4-7 Application\STC\SpirentTestCenter.tcl
    •   Note: x.xx refers to the software version.
    •   The Avalanche Commander requires TCL version 8.4.13. Download here, sign in is required; other versions of TCL are not supported. 
  3. Close the Avalanche Commander application, and relaunch.  

Version 4.10 and up

  • Ensure the correct TCL path in Avalanche Commander > Preferences > Miscellaneous > TCL interpreter as follow: 
    • Path to TCL Interpreter - C:\Program Files\Spirent Communications\Spirent TestCenter x.xx\TCL\bin\tclsh85.exe
  • NOTE: please check the release notes for the exact version of TCL supported with your s/w version. 
  • If the above steps do not resolve the problem.  Please check the followings:   
    1. ensure you are logged in as administrator and under Windows 7 the application is set to run as administrator.   
    2. ensure that the L4-7 test package is installed on the STC card(s).  For more information refer to FAQ10324 on how to upgrade & update the l4l7 test package.  
    3. ensure that the version of software in the GUI matches the firmware version on the chassis.
  • If the above does not resolve the issue you may have a corrupt installation.  It may be necessary at reinstall the Avalanche application and the f/w on the appliance/STC chassis and card. 


Product : Spirent TestCenter,Avalanche