An Avaya System SD card must be present in this slot at all times. This card holds copies of the IP Office firmware and configuration and is used as the IP500v2 control units non-volatile memory. · Each Avaya System SD card has a unique Feature Key serial number which is used for generating and validating licenses entered into the IP Office configuration. · The card stores the prompts for embedded voicemail operation and acts as the message store for embedded voicemail messages. · Prior to any planned shutdown or restart of the IP Office system, the current configuration running in the IP Office system's RAM memory is copied to the /primary folder on the System SD card and to the systems nonvolatile memory. · Following a restart, the software in the /primary folder is loaded by the IP500v2 control unit. If the required software is not present or valid a sequence of fallback options is used, see Booting from the SD Cards 155 for full details. · Following a restart, if present, the configuration file in the /primary folder is loaded by the IP500v2 control unit. If no file is present the system will check for a file in its internal non-volatile memory. If no copy is found it will generate a default configuration file. See Booting from the SD Cards 155 for full details. · Once each day (approximately between 00:00 and 00:30) the IP Office will copy the current configuration running in its RAM memory to the /primary folder on the card. · Configuration changes made using IP Office Manager are first written to the copy of the configuration file on the card and then merged with the configuration running in the IP Office system's RAM memory. · The write lock setting on cards in the System SD card slot is ignored. · Optional SD Card A card does not have to be present in this slot for normal IP Office operation. The slot can be used for various maintenance actions.