This read-only value reports the total amount of SMS message record storage space allocated in the router's DRAM for holding incoming SMS messages. An admin uses this as the ceiling against which to judge c3gSmsInSmsStorageUsed and c3gSmsInSmsStorageUnused, understanding the absolute capacity available before incoming messages must be archived or dropped. For example, on a router expected to handle a high volume of inbound SMS alerts, the admin would check this maximum capacity to decide whether more frequent archiving is needed to avoid running out of storage.