This week Cisco announced an entirely new approach to delivering rich services to the Enterprise branch office with the introduction of the ISR 4000 Series. For those folks paying attention over the last year this really was no shock. In fact the ISR 4451 announced at Cisco Live 2013 is the first member of this new series teasing the concepts and technologies represented today in an entire portfolio of platforms.

The ISR 4000 Series consists of 5 platforms that spread the architecture and technology introduced with the 4451 across a portfolio designed to meet the needs of most branch offices. With performance-on-demand, these 5 platforms hit 10 different performance levels, from 50Mbps to 2Gbps with services, giving IT departments the capability to pay for only the capacity they need with the option to increase performance with a simple license. The multi-core control/data/services plane CPUs with included virtualization through Service Containers, server replacement capabilities with the UCS E-Series and flat performance-curve with services are truly revolutionary in the industry, so how did we get here?

The answer is simple but no less impressive when you think about it. The ISR 4000 Series stands on the shoulders of one of the richest pedigrees in the entire IT industry going back more than 20 years.

Humble Beginnings

1In 1993 a gallon of gas cost $1.16 and Intel introduced the Pentium processor to handle the brand new Windows 3.1 operating system. That was also the year Cisco introduced the first router designed specifically for the branch office, the Cisco 2500 Series. With innovative interfaces like 10Mbps Ethernet, high-speed 16Mbps Token Ring and Serial WAN connections, the venerable 2500 Series was a fixture in offices until end-of-sale 2001 (and beyond). The ability to forward not just IP, but also a myriad of other popular protocols of the day made this a real breakthrough platform that the ISR 4000 Series continues today.

2The follow-on to the 2500 was the first modular branch router in the Cisco 2600 Series and 3600 Series in 1998. For the first time, users could swap out WAN interface modules across the portfolio (there was very limited modularity in late 2500 versions). The 2600 Series also introduced the concept of Integrated Services for the first time with the introduction of integrated security for VPN and firewall functionality inside the router. All of these are concepts that still exist on the ISR 4000 Series. Oh and gas had actually dropped a penny to $1.15 a gallon.

A Star is Born

Integrated Services was such a great idea. Why not name an entire product family after it and call this an Integrated Services Router? That singular idea embodies the entire design philosophy for Cisco branch routers in the 21st century. Introduced in 2004, the original ISR family of 1800, 2800 and 3800 Series built on the integrated security concepts with support for hardware accelerated VPN encryption.

3Even more services were integrated for the first time on any platform. For the first time the router could also handle voice services, wireless LAN, network analysis and a staggering array of features and interface types. Gas had skyrocketed to $2.10 a gallon so we really wanted to get as much out of a single platform in the branch as possible. (Disclaimer: That was purely coincidental. The ISR had nothing to do with the price of gas as far as we know.)

As great as the original ISRs were, network technology is always evolving and customers are always providing suggestions for improvements along the way. Enter the second generation of Integrated Services Routers, the ISR G2 [LF1] in 2009 with the 1900, 2900 and 3900 Series. With the ISR G2, Cisco tried to keep the formula that had made the first round of ISRs so successful while updating to the latest technological trends and responding to some of the suggestions on the original ISRs.

4In addition to all of the service integration from the original ISRs, the ISR G2 Series introduced dramatically faster platforms with native VPN encryption acceleration and options for integrated servers within the branch router. For the first time the concept of a single platform to provide everything a branch network needs was realized. Designed to complement the move to cloud-based services with rich application awareness and cloud connectors, the ISR G2s continue to provide an ideal mixture of traditional interfaces and features combined with cutting edge technologies like application visibility and software-defined networking. We were now up to $2.73 for a gallon of petrol and the cloud sounded so attractive.

The Newest ISR

It’s 2014 and Americans are paying on average $3.36 for a gallon of gasoline. The rising price of gas has reflected a general tightening of the belt in both personal and Enterprise spending. Companies are now looking to do more in their business with less budget, less time, and fewer people. That’s the environment that sees the introduction of the latest ISR Series which continues the theme of integrating more services in the branch with every generation.

5In addition to everything integrated from previous generations, the ISR 4000 Series introduces several new concepts to branch routing. Separate CPU complexes for control plane and packet processing is nothing new, but the ISR 4K brings this technology down into the Enterprise branch for the first time in an affordable way that looks and feels as familiar as the traditional ISRs. Virtualization of services is a popular solution and the ISR 4K includes both server virtualization as well as a built-in hypervisor for integrating network-focused virtual machines right on the router itself through Service Containers. Add in license-based performance and you have a platform designed to grow with you through additional services and performance without the need to replace hardware in the field or over-buy more capability than you need up front.

Management is a key area that is evolving in the industry and the ISR 4000 Series address this with support for both traditional network management platforms and models as well as emerging standards. That means they include support for the same IOS CLI, SNMP, and management protocols that have been around for 20 years as well as newer concepts such as REST, SDN, and programmability through Cisco onePK.

I think I see a trend here…

Not many products available today can trace their roots back directly through 20 years of continuous innovation. With every generation, the design philosophy behind branch routers from Cisco has remained the same: address the changes taking place in the Enterprise network, constantly improve the platform through ongoing customer feedback, and give the customer more while making sure that every generation integrates more than anything that came before.

Evolution of Branch Routers


Matt Bolick


SRTG Marketing - US