How can the XPhone Server be operated redundantly in case it suddenly stops working?
VMWare and other virtualisation vendors offer solutions to operate XPhone systems redundantly without hurting the C4B licensecontract. VMWare offers the VMotion and VMWare HA technology. You can move serverimages in the running system from one to another physical machine with the named solutions or restart images on new hardware in case of hardwarefailure.
Informations to VMWare HA (for Hardwarefailure):
Informations to VMWare VMotion (Imagemigration while the system is running):