Cisco 2500 series explained

The Cisco 2500 series routers are a series of 19" rack mount access routers typically used to connect Ethernet or Token Ring networks via ISDN or leased serial connections (i.e. Frame Relay, T1 etc.). The routers are based on a Motorola 68EC030 CISC processor.[1] This line of routers is no longer sold or supported by Cisco Systems.[2] They were superseded by the Cisco 2600 series, which has also reached EOL now.

Specifications

Models available

Fixed Configuration Routers
ModelEthernet AUIToken RingSerial (Sync) (DB60)ISDN BRISerial (Async)HubNotes
25011 10Mbit/s2Multiprotocol Router
250212Multiprotocol Router
25031 10Mbit/s21Multiprotocol Router
2504121Multiprotocol Router
250528 10Mbit/sRouter/hub
25072 16 10Mbit/sRouter/hub
25091 10Mbit/s28 (HD-68)Router/access server
2509-ET1 10Mbit/s28 (HD-68)Extended-temperature general purpose access server; available in the U.S. only
AS2509-RJ1 10Mbit/s28 (8x RJ45)Access Server
2510128 (HD-68)Router/access server
25111 10Mbit/s216 (2x HD-68)Router/access server
AS2511-RJ1 10Mbit/s216 (16x RJ45)Router/access server
25121216 (2x HD-68)Router/access server
25131 10Mbit/s12Dual LAN/multiprotocol router
25142 10Mbit/s2Dual LAN/multiprotocol router
251522Dual LAN/multiprotocol router
25161 10Mbit/s 2114 10Mbit/sRouter/hub
25201 10Mbit/s2 12 Low-speed (2x DB60)Multiport serial routers
25211212 Low-speed (2x DB60)Multiport serial routers
25221 10Mbit/s218 Low-speed (8x DB60)Multiport serial routers
252312 18 Low-speed (8x DB60)Multiport serial routers
Semi-Modular Routers
ModelEthernet AUIToken RingSerial (sync)ISDN BRIHub ModuleNotes
251712111 available after connection with routerRouter/Token Ring Hub
25181 10Mbit/s2123 available after connection with routerRouter/Ethernet Hub
251912 123 available after connection with router
Two distinct rings available
Router/Token Ring Hub
Modular Routers
ModelEthernetToken RingAvailable WAN modulesNotes
25241 AUI or RJ-452-wire switched 56 kbit/s DSU/CSU
4-wire 56/64 kbit/s DSU/CSU
Fractional T1/t1 DSU/CSU
5-in-one Serial (Sync)
ISDN BRI (optional NT1)
ISDN BRI with integrated NT1
3 WAN interface module slots:
•2 Serial (Sync)
•1 ISDN
25251 STP(DB-9) or UTP(RJ-45)2-wire switched 56 kbit/s DSU/CSU
4-wire 56/64 kbit/s DSU/CSU
Fractional T1/t1 DSU/CSU
5-in-one Serial (Sync)
ISDN BRI (optional NT1)
ISDN BRI with integrated NT1
3 WAN interface module slots:
•2 Serial (Sync)
•1 ISDN

Modular Routers

The modular routers had 3 interface slots available – 2 Synchronous Serial and 1 ISDN. The ISDN modules were keyed so as not to be inserted into a Synchronous WAN module slot.

The following modules were available:

CiscoPro Routers

These routers were repackaged versions of the 2500 specifically to be sold through channel partners to small and medium businesses that needed a greater ease of setup.[3] They were offered at a reduced price due to their reduced software feature set. They are characterized by a light grey/cream colored case compared to the standard dark grey colouring.

Mission-Specific Routers

'Mission-specific' models contained less memory and less hardware functionality, and were tailored to support only a subset of protocols. A 'Mission-specific' model could be upgraded to full router capability by installing a full featured IOS image and (if necessary) adding memory. There routers were mainly intended to be frame relay access devices.

The software images installed on these devices intentionally crippled the hardware (for example on-board Ethernet port on the 2501CF was disabled, and the 2503I disabled both on-board serial ports).

'Mission-specific' models included 2501CF, 2501LF, 2502CF, 2502LF, 2503I, 2504I, 2520CF, 2520LF, 2521CF, 2521LF, 2522CF, 2522LF, 2523CF and 2523LF.

The 'CF' in the model number stood for CFRAD software (Cisco Frame Relay Access Device), and the 'LF' stood for LAN FRAD (Local Area Network Frame Relay Access Device – i.e. Ethernet/Token Ring to Frame Relay). 'I' referred to an ISDN access device.

Pricing (Circa 1995) – 2520CF US$1,595 to 2523LF US$3,995

RAM/FLASH

RAM

The 2500 series uses a single 72pin FPM (70ns) SIMM with parity, and can take a maximum of 16 MB.

System boards with a revision 'A' through 'G', have an additional 2 MB of RAM soldered to the system card. Revisions 'I' through 'N' do not have any RAM soldered to the system card. This means total RAM can be 18 MB on routers having the additional 2 MB on board.[1]

On system boards with on board RAM, the SIMM socket may be left unpopulated.

FLASH

There are 2 Flash Memory sockets available (80pin, 120ns), with the maximum flash memory supported being 16 MB. Standard flash memory was 8 MB on most routers and 4 mb on 'Mission Specific' models. A boot ROM upgrade may be needed to use 16 MB of flash. The 2500 ran its IOS directly from flash memory.

An erasable, programmable read-only memory (EPROM) of 2 MB in size was used to permanently store the startup diagnostic code (ROM Monitor), and RxBoot. This ROM was held in 2x PLCC sockets and was user upgradeable.

Each unit had 32k of NVRAM, used for storage of the startup configuration.

Some 2500 models (e.g. 2511) had a PCMCIA slot installed on the board. It was intended that Cisco would send IOS updates on PCMCIA, which would then update the router. Support for this was very limited, and the device was read only.

Software

The 2500 series ran Cisco IOS (Internetworking Operating System). The initial IOS release for this model was 11.0, and the final release was 12.2(4)T[4] or 12.3(26).

On the 2500 software upgrade required booting to a BOOTROM OS with reduced functionality to have write access on the flash file system. The BOOTROM OS did not support Tokenring interfaces, making software upgrade more complex.On more recent models, the software is a compressed file on flash that first need to be extracted in RAM. As a result, the flash file systems on those routers was read/write during operation and software installation could be done during runtime.

IOS Feature Sets

The following IOS feature sets were available

The encryption on these models was restricted to DES (no 3DES supported), restricting the encryption of IPsec and SSH.

Alternative OS

uClinux is a free software project that allows a stripped down Linux installation to be run on the Cisco 2500. [5]

History

The Cisco 2500 series was introduced in 1993 and sold until 2001.[6] They were superseded by the Cisco 2600 series.

List pricing (circa 1995) ranged from US$1,595 for the 2520CF up to US$5,995 for the 2519.

See also

References

  1. Web site: Cisco 2500 Series Router Architecture. Cisco. 26 September 2014. dead. https://web.archive.org/web/20160820043228/http://www.cisco.com/c/en/us/support/docs/routers/2500-series-routers/5750-arch-2500-5750.html. 20 August 2016.
  2. Web site: Cisco 2500 Series Routers. Cisco. 23 October 2013. dead. https://web.archive.org/web/20160306121113/http://www.cisco.com/c/en/us/products/routers/2500-series-routers/eos-eol-notice-listing.html. 6 March 2016.
  3. Book: InfoWorld. 8 January 1996. InfoWorld Media Group, Inc.. 41–. 0199-6649.
  4. Web site: Cisco 2500 Series Routers Support for IOS 12.2T Feature Sets. Cisco. dead. https://web.archive.org/web/20160304051925/http://www.cisco.com/en/US/products/hw/routers/ps233/prod_bulletin09186a0080092057.html. 4 March 2016.
  5. Web site: KDV Electronics - uClinux Cisco 2500. 2021-09-24. www.kdvelectronics.eu.
  6. http://www.cisco.com/en/US/products/hw/routers/ps233/prod_eol_notice09186a008032d40b.html "End-of-Sales Announcement for Cisco 2500 Components (Cisco 2500 Series Routers) – Cisco Systems"

External links