How to Optimize Your Network Using the Cisco CSR 1000v

Does it make sense to implement a router in software? And if so, under what conditions? Hardware routers will always outperform software-based routers, by a factor of 20. It’s like pitting a Maserati against an off-the-lot Chevy. Hardware routers were built for speed.

Cisco has focused its CSR 1000v on public cloud deployment, like AWS. That’s because the customer doesn’t control the networking or their network access to the public cloud service. Putting a software router in a virtual partition on an AWS server can extend your private network reach into the cloud.

Cisco runs its software router over the IOS XE router operating system. It comes as a software module in with the CSR 1000v package. It brings almost all the functionality of IOS XE – some 3,000 features by last count.

Since mobile and personal devices are becoming an increasingly integral part of network endpoints, enterprise networks require a complex, integrated approach to secure valuable information. Without proper prevention, sensitive organizational data is vulnerable to attacks that traverse more than just a network gateway.

So what did we test?
Two different cloud environments. First we created a simulated private-cloud environment, running Red Hat Enterprise Linux atop Cisco UCS C200 series servers. We then tested it on Amazon Web Services (AWS), a public-cloud environment where users don’t have nearly the same access to, or control over, the nuts and bolts of the server hardware or network as in a private-cloud setting.

So, yes, software-based routers do have their place. The technical skill in tuning and tweaking them to achieve optimum performance when running on x86 Intel virtualized servers will remain a major challenge.

How about the settings themselves? What can users do to optimize their Cisco software router’s throughput? Well, there’s some expected configuration settings, and some not so expected.

We did see appreciably more throughput with more virtual CPUs. On AWS, going from two to eight vCPUs increased throughput tenfold. In the private cloud going from two to eight vCPUs usually at least doubled throughput. And a faster CPU will yield higher throughput. It’s almost linear: we saw a 37-percent increase in CPU speed yield a 30 percent increase in throughput.

But did you know that you’ll get better throughput – 10 to 20 percent in fact – by setting the server to a modest Packet Drop Rate (PDR) – we used the industry standard 0.01 percent drops – than using a No Drop Rate (NDR)? And do turn on SpeedStep and Turbo Boost; you’ll see another increase up to 30 percent in throughput.

Want more ways to optimize performance? Download the Cisco CSR 1000v report!