Cisco 2500 Series - Manual (Page 6)

1-10 Cisco 2500 Series Hardware Installation and Maintenance
Memory Configurations
Table 1-3 shows possible memory configurations for the router models.
Table 1-3 Memory Configurations
Memory Type Memory Capacity
Primary memory (DRAM SIMMs) 1 MB (expandable to 4, 8, or 16 MB)
Shared (packet) memory 1 MB (DRAM on the board)
1
1. The router has 2 MB of permanent (fixed) DRAM memory and a DRAM SIMM socket for upgrading
the memory. 1 MB of this permanent memory is used by the CPU and is called primary memory. The
other 1 MB of memory is used by the network interface ports to store packets and is called shared or
packet memory. When a DRAM SIMM is installed in the DRAM SIMM socket, all of the DRAM
memory on this SIMM becomes primary memory for the CPU, and the 2 MB of DRAM that is
permanent on the board becomes shared memory.
System-code memory (Flash or PROMs) 4 MB (expandable)
Boot ROM memory 2 MB (expandable)
Nonvolatile RAM (NVRAM) memory 32 KB