Identifying Router Components and Accessories

Cisco Router History and Architectural Overview

Since the early 1990’s, Cisco has taken a new approach towards device modularity on enterprise network devices. In the past; the Cisco 2500 Series Routers, excluding the 2524 had fixed port(s) configuration ranging from Ethernet, Serial, Token Ring, ISDN and Terminal Lines which in this case it imposed a limit for network investment protection and scalability within an enterprise networks.

With the announcement and release of the Cisco 3600 Series Routers in 1996, businesses felt a relief in investment protection as they were not required to replace an entire router when upgrading WAN and/or LAN link aggregation. Companies could easily migrate from using an ISDN line to a content line with the swap of a WIC (WAN Interface Module) as well as upgrade LAN ports from 10Base-T to 10/100Tx with the change of a NM (Network Module).

The Cisco 2600 Series routers, announced in March of 1998 was the next milestone for Cisco Systems Inc., a new generation Multi-Service router(s) engineered to provide secure, wire-speed delivery of simultaneous voice, data, video, and wireless services. However, the Cisco 2600 Series platforms lacked one feature that was available on the Cisco 3600 Series routers which upset several network engineers throughout the industry which was the PCMCIA flash card slots. Engineers that were familiar with the 3600 Series platforms found that during disaster recover, the restoration of configuration files as well as IOS images was simple with the change of a PCMCIA Flash card.

The 3700 Series platforms which include the 3725 and the 3745 were announced around the same time as the Cisco 2600 Series. These platforms was a major stepping stone in Cisco’s device architecture as these platforms introduced the removable Compact Flash (CF) card memory which is commonly used with Digital Cameras. Even today, devices such as the 2800, 3800 Series ISR (Integrated Services Routers), ASA 5500 Series Firewalls, and countless other platforms were designed to utilize Compact Flash (CF) Cards. CF cards proved to be several times faster and more resilient than previous storage technology utilized by Cisco devices.

In May of 2002, Cisco launched the new Cisco 2600XM Series Multi-Service Routers which included several upgraded system architecture features such as a revision of the current Motorola Processor, 125MHZ SDRAM, 16MB integrated flash with a max flash of 48MB, and support of 128MB RAM.

Later, with the release of 12.2(8r) bootrom, the 2600XM Series Multi-service Routers physically supported 256MB RAM. However, when 12.2(8r) was first introduced it only provided the “future-ability” to use 256MB RAM. At that given time the Cisco IOS for the 2600XM were still limited to 128MB RAM, however the benefit from using 256MB RAM and the 12.2(8r) bootrom is that the bootrom would decompress the Cisco IOS image into address space not addressed by IOS kernel. Traditionally when the images got larger on the 2600XM platform the processor addressable memory space shrunk as the images are decompressed and loaded into memory upon boot (unlike the 2500 series which are ran directly from flash) This gave a significant performance boot on the 2600XM platforms. At that time the upgrade was offered, using 256MB RAM on a 2600XM platform gave you an additional 50-60MB or so as the decompressed image did not reside in IOS processor addressable memory. If you do the show memory command on a 2600XM with 256MB RAM running 12.3T you’ll see that the process should have 128MB available to address. IOS versions released after October of 2004 had the ability to address the full 256MB ram minus the decompressed image.

The Cisco 2691 router was also released at the same time as the 2600XM and it’s the fastest platform in the 2600 Series portfolio. Designed with higher throughput, scalability, and versatility in mind. The Cisco 2691 Series router was the baby brother to the Cisco 3725 Series router. In a side by side comparison, they look very similar; However performance and modularity and PRICE sets them apart.

The 1800, 2800 and 3800 Series routers support the HWIC (High-speed WAN Interface Card’s) which supports 400Mbps aggregate (shared among all slots) whereas previous WIC technology only supported 8Mbps aggregate per PCI BUS.

Example; the 2600XM Series has two integrated WIC slots on a shared bus. The 2600XM supports a single WIC-2T port operating at 8Mbps speed or two ports at 4Mbps but due to the shared bus, the other WIC slot cannot be used. This limitation also applied to the NM-1FE2W, NM-1FE1R2W, NM-2FE2W and NM-2W network modules.

The 2800 Series ISR Routers (Excluding 2801) have four HWIC slots supporting 400Mbps aggregate (400Mbps per all slots on a chassis) and one or more NME (Network Module Enhanced) slots operating at a shared 1.2Gbps across all slots within the platform whereas its predecessor; Network Module was only capable of operating at shared speeds up to 600Mbps across all network module slots within the platform.

Several platforms including but not limited to the 2600 Series, 3700 Series and even newer Integrated Services Routers have internal expansion slot(s) called AIM slots. AIM, which stands for Advanced Integration Module is used for expanding the capabilities of a particular platform. There are a vast range of Advanced Integration Modules available from Cisco such as the AIM-CUE which is the Cisco Unity Express module that provides voice mail functionality for the Unified Communications Manager Express platform or even the AIM-VPN module which is a cryptographic processor which offloads cryptographic functions from the routers processor thus increasing router performance.

Click on the Router Matrix Chart tab to view charts of common routers including ports, slots, performance, max RAM and FLASH;

Common Cisco Router Specifications

Cisco 2500 Series Routers

Notes: This chart was compiled for lab use only; these routers should NEVER be used in production.
2500’s have a Motorola 68030 20 MHz processor. Have 1x 80pin SIMM RAM slot & 2x pin SIMM Flash slots.
Some 2500 series routers have 2MB DRAM soldered onto the mainboard used for buffer/shared memory.
Async Lines can be used as modem ports or terminal lines used in access servers.
*H = High Speed Synchronous Serial Interface.
*L = Low Speed Synchronous/Asynchronous Serial Interface.

Cisco 1600 Series Routers

Notes: 1600 Series used PCMCIA Flash Cards.
1600 Series routers use a Motorola 68360 33Mhz Processor.

Cisco 3600 Series Routers

Notes: 3600 Series routers are completely modular and support PCMCIA Flash Cards.
3620 & 3640 use an IDT R7000 RISC Processor
3631 uses a PMC-Sierra RM7061A RISC Processor
3660’s use a QED RM5271 RISC Processor

Cisco 2600 & 2600XM Series Routers

Notes: The 2600 Series utilize the MCP860 PowerQUICC Processor.
The 2612 & 2613 have an RJ45 Token Ring port.
The 2691 supports both internal and CF (Compact Flash) Storage.
2620 & 2621 can support 32MB Flash with 12.1(3r) bootrom or later.
The 2600XM Series can support 256MB DRAM using 12.2(8r) bootrom or later.

Cisco 1700 Series Routers

Notes: 1700 Series Routers use a Motorola MCP RISC PowerQUICC Processor
1711 & 1712 have an integrated VPN Hardware services module.
Models 1720 and later support an installable VPN Hardware Services Module.
The 1711 Router has an integrated 56k v.90 analog modem.
The 1760 has 4 available VIC slots, two of which can only support WIC’s.

Cisco 3700 Series Routers

Notes: 3700 Series routers support High Density Service Modules (HDSM’s)
3745 Can support 512MB DRAM (2x256MB SODIMM) using 12.3(6r) Bootrom.
3700 Series routers support Online Insertion & Removal (OIR) of NM’s and Power Supplies.

Cisco 1800 Series Routers

Notes: All 1800 Series use a QED RM52xx Processor
All 1800 Series excluding the 1841 have an 8 Port 10/100 Managed Switch.
The 1841 does not have integrated WiFi but supports WiFi via the HWIC-AP
The 1841 has a single USB 1.1 Port, Other 1800 Series have USB 2.0
The 1841 support’s the aDSL & G.SHDSL WIC and HWIC’s.
The 1841 has an AIM Slot (Advanced Integration Module)
The 1841 supports the majority of existing WIC’s, VWIC’s and VIC’s (Data Mode Only)
The 1805 has an integrated Cable DOCSIS 2.0 port and a 4 10/100 Port Managed Switch
The 1861 has 4x Integrated FXS ports, 2x BRI S/T, 8 Port 2x POE 10/100 Managed Switch.

Cisco 2800 Series Routers

Notes: The 2800 Series Routers have an Integrated Cryptographic Processor for VPN Services.
The 2800 Series Routers have installable Digital Signal Processors (DSP’s) for voice Services.
The 2801 Does not support the HWIC-1GE (1 Port SFP HWIC)
The 2800 Series supports the HWIC-1FE but not the HWIC-2FE. HWIC-2FE’s require 3800 Series.

Cisco 3800 Series Routers

Notes: The 3800 Series routers support High Density Service Modules (HDSM’s)
The 3800 Series routers have a single Small Pluggable Form-factor (SFP) port.
The 3825 Uses a Single-core Broadcom BCM1125H 500 MHz Processor.
The 3845 use a Dual-Core Broadcom BCM1250 650 MHz Processor.