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Cisco 4000 Series Memory Update

Product Bulletin #284

Introduction

This Product Bulletin contains information regarding various memory issues on the Cisco 4000 Series routers. There is potential for confusion between the three models in the 4000 Series and surrounding the factors which affect memory requirements. There has also been requests for information regarding alternate sources for memory. This Bulletin attempts to clarify the issues and provide a single source for answers to memory questions for the Cisco 4000 Series.

The three models in the Cisco 4000 Series are: 

  Cisco 4000      the original 4000, new unit shipments stopped 6/94
  Cisco 4000-M    memory enhanced 4000, shipments started 6/94
  Cisco 4500      high performance model, shipments started 8/94
Each has (had) different standard memory configurations, different upgrade options and different minimum memory requirements for certain IOS versions, network sizes and functional requirements. Some of the major factors which can affect memory requirements include:

Given the many variables which can affect memory requirements, it is best to have a Cisco expert analyze network designs and recommend memory configurations. This Product Bulletin provides the basic information needed to determine what memory options are available, what minimum requirements are some basic guidelines for selecting memory options and some alternate sources for the memory.

Memory Options and Requirements

Each of the platforms in the 4000 Series has a standard memory configuration and a set of supported memory options. Each of the current IOS software streams has a set of minimum memory requirements. Tables 1a and 1b below are a comprehensive compilation of the current hardware configurations and minimum requirements for various IOS releases. 

Table 1a: Standard and Optional Configurations
---------------------------------------------------------------------
MEMORY TYPE        STANDARD CONFIG. (MB)      OPTIONAL CONFIGS. (MB)
=====================================================================
Cisco 4000
  Boot EPROM               1                           2
  System FLASH             2                           4
  Main DRAM                4                          16
  Shared DRAM              1                           4
---------------------------------------------------------------------
Cisco 4000-M
  Boot EPROM               1                           2
  System FLASH             4                           8
  Main DRAM                4                       8, 16, 32
  Shared DRAM              4                          16
---------------------------------------------------------------------
Cisco 4500
  Boot EPROM               4                           8*
  System FLASH             4                           8
  Main DRAM                8                          32
  Shared DRAM              4                          16
---------------------------------------------------------------------
*Not currently available


Table 1b: Minimum Memory Requirements
-----------------------------------------------------------------------------
                            MINIMUM REQUIREMENTS FOR RELEASES (MB):
               9.1  9.14  9.21  10.0  10.1  10.2.1   10.2.1   10.2.1   10.2.1
MEMORY TYPE                                  Base      Ent      DT       IP
=============================================================================
Cisco 4000
  Boot EPROM    1     1     2     2    n/a     2       n/a      n/a      n/a
  Sys FLASH     2     2     2     2    n/a     2       n/a      n/a      n/a
  Main DRAM     4     4    16    16    n/a    16       n/a      n/a      n/a
  Shared DRAM   1     1     4     4    n/a     4       n/a      n/a      n/a
-----------------------------------------------------------------------------
Cisco 4000-M
  Boot EPROM   n/a    1     2     2    n/a     2       n/a      n/a      n/a
  Sys FLASH    n/a    4     4     4    n/a     4       n/a      n/a      n/a
  Main DRAM    n/a    4     8     8    n/a     8       n/a      n/a      n/a
  Shared DRAM  n/a    4     4     4    n/a     4       n/a      n/a      n/a
-----------------------------------------------------------------------------
Cisco 4500
  Boot EPROM   n/a   n/a   n/a   n/a    4     n/a       4        4        4
  Sys FLASH    n/a   n/a   n/a   n/a    4     n/a       4        4        4
  Main DRAM    n/a   n/a   n/a   n/a    8     n/a      32        8        8
  Shared DRAM  n/a   n/a   n/a   n/a    4     n/a       4        4        4
-----------------------------------------------------------------------------

Memory Requirements for the Cisco 4000 Series

As shown in Table 1a and 1b above, there are certain minimum memory requirements for each of the IOS feature sets. In practice of course, many factors affect the memory requirement on a router. This section contain some guidelines for determining when to recommend additional memory upgrade for the Cisco 4000 Series.

Main DRAM

The Cisco 4000 Series runs from an image stored in main DRAM. This memory is also used by the system for tables and stacks. Therefore, the amount of main memory required is determined by the size of the image and by the configuration of the internetwork.

On the Cisco 4000 and 4000-M platforms, 4 MB of Main DRAM is sufficient for most routers running 9.1 and 9.14 images. A memory upgrade was required only for routers in very large internetworks of with very large and complex access list requirements running those older releases. Virtually all 4000 and 4000-M routers running 9.21 and 10.X software will require a memory upgrade. Only very small internetworks with minimal protocol support requirements could run these releases in 4 MB.

For the Cisco 4500, the memory requirement can be reduced by running a subset image. The minimum memory size for the 10.1 Enterprise and the 10.2 IP and Desktop images is the standard 8 MB. For the 10.2 Enterprise Set the minimum is 32 MB. More detailed rules for the Cisco 4500 are contained in "Cisco 4500 Update."

Shared DRAM

The Cisco 4000 Series use shared DRAM, also known as packet memory, for handling user data. The recommended amount of shared memory is determined solely by the number of physical and/or virtual interfaces supported by the router. The original Cisco 4000 came standard with 1 MB of Shared DRAM. That was sufficient for routers with up to 5 interfaces. As higher speed (FDDI) and density NPMs and virtual interfaces became available, 1 MB was clearly not enough shared memory for a standard configuration. Therefore, the standard configuration was changed to 4 MB of shared DRAM for both the Cisco 4000-M and for the Cisco 4500. That is sufficient for most configurations with less then 24 physical or virtual interfaces. For routers with multiple ISDN BRI ports or with 24 or more physical and virtual interfaces, we recommend an upgrade with the 16 MB shared DRAM option.

System Flash

The Cisco 4000 Series images are stored, compressed, in Flash memory. For the Cisco 4000 images up to release 9.21 have fit in the 2 MB Flash memory. That boundary is very close to being exceeded, however, so if a customer desires upgrades to 10.0 or beyond, you should recommend the flash upgrade. The earliest releases of 10.0 will also fit however there is no room for growth so even a future maintenance release won't fit.

The Cisco 4000-M and 4500 come standard with 4 MB of system flash. This is sufficient for all current releases and still leaves room for future image growth. Customers who wish to store two images should upgrade to the 8 MB option. That is the case where the router is used as a TFTP server for other Cisco routers.

Boot Flash

The Cisco 4500 Boot image is also stored in Flash. The standard configuration of 4 MB will be sufficient for the foreseeable future. Currently no upgrades are offered.

Boot EPROM

The Cisco 4000 and 4000-M Boot EPROMs are 2 MB for recent releases. Some older releases were contained in 1 MB EPROM.

Memory Upgrade Orderability Information

Table 2 below contains the most current list of available memory options for the Cisco 4000 Series. Three sections in the table list the options for each of the Cisco 4000, the Cisco 4000-M and the Cisco 4500. 

Table 2: Memory Upgrade Options
---------------------------------------------------------------------------
PRODUCT NUMBER     DESCRIPTION
===========================================================================
Cisco 4000
 MEM-NP4F=         Additional 2 MB of Flash EPROM (total 4 MB)
 MEM-NP16M=        Additional 12 MB of Main Memory (total 16 MB)
 MEM-NP4S=         Additional 3 MB of Shared Memory (total 4 MB)


Cisco 4000-M
 MEM-NP8F-M(=)     Additional 4 MB of Flash EPROM (total 8 MB)
 MEM-NP8M-M(=)     8 MB Upgrade, replaces 4 MB Main Memory (total 8 MB)
 MEM-NP16M-M(=)    16 MB Upgrade, replaces 4 MB Main Memory (total 16 MB)
 MEM-NP32M-M(=)    32 MB Upgrade, replaces 4 MB Main Memory (total 32 MB)
 MEM-NP16S-M(=)    16 MB Upgrade, replaces 4 MB Shared Memory (total 16 MB)


Cisco 4500
 MEM-NP8F-P(=)     Additional 4 MB of Flash EPROM (total 8 MB)
 MEM-NP32M-P(=)    32 MB Upgrade, replaces 8 MB Main Memory (total 32 MB)
 MEM-NP16S-P(=)    16 MB Upgrade, replaces 4 MB Shared Memory (total 16 MB)
---------------------------------------------------------------------------
Notes:

  1. For new system orders, order the memory upgrade part number without the "=" suffix.

  2. For upgrades to existing systems in the field order the memory part number with the "=" suffix.

  3. Part numbers shown in the list above with "(=)" suffix can be ordered either with a new system or as a field upgrade.

  4. MEM-NP16S-M(=) is a new option. This shared memory upgrade for the Cisco 4000-M is orderable now and will first ship September 19, 1994

Memory Components Approved Vendor List

Each of the memory options, listed in Table 2 above, consists of standard memory components and, in some cases, additional proprietary parts. Since many of the parts are standard off-the-shelf memory components, customers have occasionally expressed an interest in purchasing memory from third parties. The lists of approved vendors for standard parts are included below for convenience and in order to maintain the customers warranty or service contract in good standing. As of this date, all of the DRAM options are available from third parties while all of the Flash options are proprietary and must be purchased from Cisco.

Cisco 4000 Memory Options

Cisco 4000-M Memory Options

Cisco 4500 Memory Options

Posted: Tue Nov 11 13:36:55 PST 1997
Copyright 1996 © Cisco Systems Inc.