The subscriber table contains configuration information per subscriber line. Non-assigned entries are identified by NULL string for the subscriber name. It contains provisionable information such as subscriber name, line rate and subscriber line state.. The subscriber provisioning request may fail, if the targeted subscriber line is under test. Changes to the subscriber information are temporary until user actually requests save operation through systemSaveCnfg. Only at that point system writes information in the NVRAM storage and information becomes permanent.