Cisco 4400 and 4300 Series ISRs, the Differences

October 19 2017 , Written by Cisco & Cisco Router, Network Switch Published on #Networking, #Cisco Routers, #Cisco & Cisco Network, #IT

Cisco ISR 4000 series is the trend among the hardware routers. The popular 4000 Series

ISR models are users’ options. Why? You can read more about the The “Always On” Cisco ISR 4000 Will Replace the Popular Cisco 1900, 2900, and 3900 Series-Benefits of Migrating to Cisco 4000 Series Integrated Services Routers

The 4000 Series comes to five platforms: the 4451, 4431, 4351, 4331, 4321 and 4221 ISRs.

Learn more: ISR 4221, the New Cisco DNA-Ready Platform

Cisco 4000 Series: Technical Highlights and Comparison

The Cisco 4000 Series uses Cisco IOS XE Software, the same Linux-based OS found on the bigger ASR 1000 Series platforms. Cisco IOS XE retains the design and user interface of the Cisco IOS OS used by previous generation Cisco routers, yet allows the use of multi-core CPUs. This setup facilitates separation of the data and control planes and uses dedicated CPUs for services.

Because the services plane is separate from the data and control planes, the router can handle more and heavier services on a single platform, allowing an office to consolidate devices. Solutions such as Cisco Unified Border Element (CUBE), Cisco Unified Survivable Remote Site Telephony (SRST), or various routing services can be deployed more easily and efficiently on a single ISR. In addition, for many of the services, such as CUBE, the scalability is significantly greater without added costs per port. Performance also remains solid across most typical branch-office deployments, providing application-specific integrated circuit (ASIC)-like performance in a highly reliable platform.

X86-based embedded service containers offer dedicated virtualized computing resources that include CPU, disk storage, and memory for each service. An industry-standard hypervisor presents the underlying infrastructure to the application or service. This design offers better scaling and flexibility than a tightly coupled service. Deployment with zero footprint, security through fault isolation, and the flexibility to upgrade network services independently of the router software are other benefits.

And the Cisco 4400 and 4300 Series ISRs have a very similar user interface design.

The biggest difference to most users is that the 4400 Series supports dual power supplies, whereas the 4300 Series does not; this difference makes the Cisco 4451 and 4431 the preferred choices for organizations that cannot tolerate any downtime.

The 4400 and 4300 Series are both designed with the same base architecture as their close relative, the ASR 1000 Series, using distributed control and data plane resources.

The 4400 Series routers have a physical separation between control and data planes, using dedicated CPU sockets for each. The 4300 Series uses a single socket with multiple CPU cores, providing the distributed control plane, data plane, and service plane resources. This is, however, a difference most users will never be aware of.

Figure1 shows the Cisco 4400 Series architecture.

The abbreviations in the figure are as follows:

FPGE: Front-panel Gigabit Ethernet. The Ethernet interfaces on the front panel.
ISC: Internal services card. An internal module used for expanding the capabilities of the system. Commonly used for digital signal processor (DSP) modules.
SM-X: Enhanced service module. A larger module type used mainly for Cisco UCS E-Series Server blades and high-density Ethernet switch modules. Some of the SM-X modules are compatible with the ISR G2 product line.
NIM: Network interface module. Half the size of an SM-X, and generally used for WAN, voice, and lowdensity Ethernet interfaces. NIMs are not compatible with previous-generation ISRs.

Figure1. Cisco 4400 Series Architecture

The Cisco 4400 Series uses two multicore CPU complexes for the data plane (packet processing) and control and services planes. In Cisco IOS XE Software, classic Cisco IOS Software runs as a single daemon within a Linux OS, helping ensure control-plane protocol compatibility with all other Cisco routers. This setup is indicated as “Cisco IOS Software” in the figure. Additional system functions now run as additional, separate processes in the host OS environment. “ISR-WAAS” in the figure is an example of a typical virtualized service in a Cisco IOS XE Software service container. As with the previous ISR G2 routers, a multigigabit fabric supports direct intercommunication on Layer 2 between the Internal Services Card (ISC), Cisco SM-X EtherSwitch modules, and network interface modules (NIMs) without having to be routed through the host router data plane.

Figure2 shows the Cisco 4300 Series architecture, which is similar to the 4400 Series but does not include physical separation of the control and data planes. All functions are, however, exactly the same, with identical enduser experiences and feature support.

Figure2. Cisco 4300 Series Architecture

Individual Models in the Cisco 4000 Series

Figure3. Cisco 4451-X ISR

The Cisco 4451-X is suggested for migration from the existing Cisco 3925E and 3945E routers. It offers 1-Gbps performance, upgradable to 2 Gbps, in a 2-rack-unit (2RU) form factor with three NIM slots and two enhanced service module (SM-X) slots.

The 4451-X includes an option for built-in redundant power.

● 4-core processor (one control and three services processors)

● 10-core data plane

● Single or double-wide Cisco UCS E-Series support

● Up to 16-GB control and services memory

Figure4. Cisco 4431 ISR

The Cisco 4431 is suggested for migration from the existing Cisco 3925 and 3945 routers. It offers 500-Mbps performance, upgradable to 1 Gbps, in a 1RU form factor with three NIM slots. Like the 4451, the 4431 includes an option for built-in redundant power.

● 4-core processor (one control and three services processors)

● 6-core data plane

● Up to 16-GB control and services memory

Figure5. Cisco 4351 ISR

The Cisco 4351 is suggested for migration from existing Cisco 2951 routers. It offers 200-Mbps performance, upgradable to 400 Mbps, in a 2RU form factor with three NIM slots and two SM slots.

● 8-core CPU with four data-plane cores and four cores for control-plane and containerized services

● Single or double-wide Cisco UCS E-Series support, and up to 16-GB control and services memory

Figure6. Cisco 4331 ISR

The Cisco 4331 is suggested for migration from the existing Cisco 2911 and 2921 routers. It offers 100-Mbps performance, upgradable to 300 Mbps, in a 1RU form factor with two NIM slots and one SM slot.

● 8-core CPU with four data-plane cores and four cores for control-plane and containerized services

● Single-wide Cisco UCS E-Series support, and up to 16-GB control and services memory

Figure7. Cisco 4321

The Cisco 4321 is suggested for migration from the existing Cisco 2901 and 1941 routers. It offers 50-Mbps performance, upgradable to 100 Mbps, in a 1RU desktop form factor with two NIM slots and no SM slots.

4-core CPU with two data-plane cores, one control-plane core, and one core dedicated for services
Up to 8-GB control and services memory

The Cisco 4000 Series is designed to help branch and remote offices do more with less. These routers provide higher bandwidth for heavy service combinations and greatly enhanced WAN management. They also introduce embedded X86-based virtual machines together with options for data center–class servers, and an unprecedented flexibility in upgrading.

All in all, the 4000 Series provides the branch office with less need for rack space; lower cost for maintenance, power, and cooling; faster rollout of new services; and less time spent by IT staff managing routers.

Compare ISR 4000 Models