Chapter 2: About the HSIM-W6HSIM-W6 User’s Guide 15ISDN Back-upThe ISDN back-up feature provides a back-up link for a remote site or branch office when one ormore primary WAN interfaces for a frame relay circuit or a nailed-up PPP connection fails. TheWPIM-S/T serves as the backup medium for this primary connection. The WPIM-S/T uses theISDN interfaces to back-up any primary interfaces which have been configured for ISDN back-up.Time to Connect, Time to Disconnect, Connect Retries, Back-up Override, Input Idle Time-outand Output Idle Time-out, are the six back-up parameters used to manage the ISDN Back-upfeature on the HSIM-W6, and are described as follows:Time to Connect — Time to Connect allows you to configure the amount of seconds the primaryinterface can be in a failed state, before attempting to switch over to the back-up interface.Time to Disconnect — Time to Disconnect allows you to configure the amount of seconds therestored primary interface must remain connected, before attempting to switch over from theback-up interface.Connect Retries — Connect Retries allows you to configure the number of tries to restore theback-up interface, before giving up.Backup Override — Backup Override forces the back-up interface to remain connected, anddoes not allow the back-up interface to switch back to the primary interface, even if the primaryinterface is restored.Input Idle Time-out — Input Idle Time-out allows you to determine the amount of time necessaryfor data packets to be received, before the interface is automatically disconnected.Output Idle Time-out — Output Idle Time-out allows you to determine the amount of timenecessary for data packets to be transmitted, before the interface is automatically disconnected.
