Nortel Networks Circuit Card - Manual (Page 814)

Page 814 of 906 NTDK20 Small System Controller card
553-3001-211 Standard 3.00 August 2005
Memory
The majority of system and customer configured data is both controlled and
stored on the NTDK20 SSC card’s Flash ROM. An active and backup copy
of customer data is also kept on the Flash ROM.
In the event of data loss, the NTDK20 SSC card also retains a copy of
customer files in an area called the Backup flash drive. The NTDK20 SSC
card is equipped with 8MB of temporary memory space called DRAM.
DRAM functions much like RAM on a computer system. It stores and
processes temporary automated routines and user-programmed commands
while the system is running. The DRAM on the SSC card stores operating
system files, user files, overlay data, patch codes, and the active copy of the
customer database.
The NTDK20 SSC card’s Flash daughterboard is the NTTK25. It performs
most of the system software storage and data processing.
NTTK25 daughterboard
The NTTK25 is a 48 MB daughterboard comprised of Flash ROM and
Primary Flash drive. It is required in the Call Server and MG 1000S.
The Flash ROM holds 32 MB of ROM memory, comprising operating system
data and overlay programs. Flash ROM is expandable using an expansion
flash daughterboard.
The Primary Flash drive contains 16 MB of storage space. Most of the data
storage is allocated to the Primary Flash drive – the main storage area of
customer configured data.
Other system data such as the Secure Storage Area (SSA) also resides in the
Flash drive. The SSA holds data that must survive power interruptions.
The Boot ROM is a 2 MB storage device located on the NTDK20 SSC card.
The Boot ROM contains the boot code, system data, patch data, and the
backup copy of the Primary Flash drive’s customer database.