To further enhance the availability of LSMS functions, you can choose to implement a shadow LSMS, where a shadow LSMS is an entire LSMS (with its own service provider ID) located in a separate geographical location from the main LSMS. Having a shadow LSMS available reduces the time needed to restore service in situations of severe error or disaster, such as fire or flood. The following types of shadow strategies are available:
Active shadow—a shadow LSMS that is connected to NPACs
Inactive shadow—a shadow LSMS exists but is not connected to NPACs
For more information about a shadow LSMS, and recovery procedures for each strategy, see Recovering from Site Failures. This chapter also describes the procedure for restoring a main LSMS after a site failure when no shadow is available.