Upgrading the DRAM SIMM
in the Cisco 2500 Series Routers

Warning To prevent shock hazard and injury, do not touch the power supply and fan assemblies. These components are not user-serviceable.

Installing Primary-Memory DRAM SIMMs

The router contains primary and shared (or packet) memory. Primary memory size, in kilobytes (KB), is displayed in the system banner on the console screen. Primary and shared memory are 1 MB each of the dynamic random-access memory (DRAM) on the system board.

After booting your system, the system banner displays the amount of primary memory installed. The following example shows a system with 1 MB (1024 KB) of primary memory. (The system does not display shared memory.)

System Bootstrap, Version (2.1), SOFTWARE
Copyright (c) 1986-1993 by cisco Systems
2500 processor with 1024 Kbytes of main memory 
>

If you use very large routing tables or many protocols, you might need to expand primary memory. This expansion might also be necessary when the router is set up as a connection device between large external networks and your internal network.

Tools and Equipment Required

• Medium-sized flat-blade screwdriver (1/4 inch [0.625 cm])
  

• ESD-preventive wrist strap
  

• The appropriate DRAM SIMM for your router model
  

Primary Memory Configurations

You can upgrade to 4 MB, 8 MB, or 16 MB of DRAM. Table 1 lists the upgrade amounts and corresponding memory configurations.

Table 1 : Memory Configurations

Upgrade DRAM	Memory Configuration
4 MB	1 MB x 36 DRAM SIMM
8 MB	2 MB x 36 DRAM SIMM
16 MB	4 MB x 36 DRAM SIMM

Approved DRAM SIMMs

You can order DRAM SIMMs from Cisco Systems or an approved vendor.

Table 2 lists the upgrade amounts and corresponding Cisco Systems product numbers.

Table 2 : Cisco Systems DRAM SIMMs

Upgrade DRAM	Cisco Systems Product Number
4 MB (1 MB x 36, 70 ns DRAM SIMM)	MEM1X4D=, MEM-6M=
8 MB (2 MB x 36, 70 ns DRAM SIMM)	MEM-1X8D=
16 MB (4 MB x 36, 70 ns DRAM SIMM)	MEM-1X16D=, MEM-18M=

Table 3 lists approved 70 nanosecond (ns) DRAM SIMM vendors.

Table 3 : Approved DRAM SIMM Vendors

Upgrade DRAM	Vendor	Vendor Part Number
4 MB (1 MB x 36, 70 ns DRAM SIMM)	Hyundai	HYM536100AM-70
	Micron	MT9D136M-7
	Mitsubishi	MH1M36ASDJ-7
	Mitsubishi	MH1M36BNDJ-7
	NEC	MC421000A36BE-70
	OKI	MSC23136B-70BS12
	Samsung	KMM5361003C-70
8 MB (2 MB x 36, 70 ns DRAM SIMM)	Smart Modules	SM536C2000-7
16 MB (4 MB x 36, 70 ns DRAM SIMM)	Hitachi	HB56D436SBR-7AGS
	Hyundai	HYM536410M-70
	Mitsubishi	MH4M36ANXJ-7
	NEC	MC-424000A36BE-70
	Samsung	KMM5364100A-70

DRAM SIMM Installation

Following is the procedure for installing DRAM SIMMs:

Step 1 Turn OFF power, but to channel ESD voltages to ground, do not unplug the power cord.

Step 2 Attach an ESD-preventive wrist strap.

Step 3 Open the cover according to the procedure in the section "Opening the Chassis."

Step 4 Turn the chassis so the system board is opposite the position shown in Figure 2, with the primary memory DRAM SIMM socket toward you.

Step 5 Remove the existing DRAM SIMM (if installed) by pulling outward on the connectors to unlatch them (shown in Figure 3). Be careful not to break the holders on the connector.

Caution To prevent damage, do not push on the center of the SIMM. Handle the SIMM with care.

Figure 3 : Removing and Replacing the DRAM SIMM

Step 6 Using the system board orientation shown in Figure 2, position the new SIMM so that the polarization notch is located at the right end of the SIMM socket. Note that the orientation of the system board is opposite of that shown in Figure 3.

Step 7 Insert the new DRAM SIMM by sliding the end with the metal fingers into the SIMM connector socket at approximately a 45-degree angle to the system card. Gently rock the SIMM back into place until the latch on either side snaps into place. Do not use excessive force, or the connector could break.

Step 8 Replace the router cover using the procedure in the section "Closing the Chassis."

Step 9 Connect the router to a console terminal.

Step 10 Turn ON the power to the chassis. If error messages relating to memory are displayed, repeat steps 1 through 7, taking care to firmly seat the SIMM in its socket.

Closing the Chassis

This section explains how to close the chassis.

Tools Required

The following tools are required to replace the cover:

• Medium-sized flat-blade screwdriver (1/4 inch [0.625 cm])
  

• Size M 3.5 hex-head nut driver (optional)
  

Cover Replacement

To replace the cover, follow these steps:

Step 1 Position the two chassis sections as shown in Figure 4.

Step 2 Referring to Figure 4, press the two chassis sections together and ensure the following:

• The top section fits into the rear of the bottom section (See Part A in Figure 4.)
  

• The bottom section fits into the front of the top section (See Part B in Figure 4.)
  

• Each side of the top and bottom sections fits together (See Part C in Figure 4.)