cloud computing

Software-based networking: Critical to meet requirements of Cloud Environments

By: George Chacko, Principal Systems Engineer & Lead Technical Consultant, Brocade India

While cloud moves from vision to reality, a cloud data center is only as strong as its weakest link. While the overall IT infrastructure can be highly optimized for cloud, it simply cannot be leveraged well if the network infrastructure is stuck in the old hardware-based mode. Unfortunately, the traditional networking infrastructure has not been modernized the way server and storage infrastructure has been over the past decade. The inability to treat networking workloads with the same agility as other parts of the infrastructure has a huge and compounding effect on the effectiveness and efficiency of the entire cloud. Software-based networking is the most effective way to deploy critical networking tasks while meeting the fundamental business requirements of a cloud.

There are variety of ways to leverage software defined networking (SDN) to achieve both business and infrastructure requirements for a successful cloud offering. A few key opportunities follow below:

Secure Connectivity

Data on the cloud can be accessed through the internet, requiring every user’s connection to be encrypted for security. This requires VPN infrastructure at every single access location and within the cloud itself. SDN can significantly improve cloud network security using virtualization techniques. Within the cloud a new VPN virtual machine can be started in moments, using a small fraction of an existing server. This helps to reduce the cost of installing a hardware device, power consumption and space. The customer can deploy the same software or virtual machine at each access location rapidly and with minimal expense, as a “secure cloud connector.”

Instant Firewalls

A customer not only must firewall its sensitive systems, but should also ensure security in a multitenant environment using a shared connection to the public internet. Using traditional networking would require a lot of traditional hardware firewalls at a high cost, slow deployment, and with deep inflexibility. Software-based networking allows firewalls to be instantly deployed as virtual machines with no operating cost. The benefits for the customer are obvious (dynamic provisioning, seamless scale-up), while the cloud provider eliminates significant amounts of both CapEx and OpEx.

Dynamic Subnets

Network topologies in use on a customer’s premise must be enabled when their infrastructure is cloud-based. Traffic needs to be routed and subnets / Virtual Local Area Network need to be established. Software-based networking puts easy, low-cost and highly flexible capabilities in the cloud customer’s hands. Whether booted on an entire piece of hardware or deployed as a virtual machine, critical functions such as IP routing, address management, Network address translation, authentication, QoS and others can be rapidly deployed where and when the customer needs them.

Disaster Recovery

When all IT functions of an organization are software based it helps cloud customers to replicate their operational infrastructure design at other locations as a disaster recovery measure. The process becomes extremely costly in terms of CapEx and OpEx if the key functions are tied to traditional networking devices. With software-based networking, the customer’s total IT architecture can replicate easily to other locations. Similarly, changes to topologies and policies are easy to push to the disaster recovery replica. This is key to cost-effective and dynamic disaster recovery services in the cloud.

Highly Efficient Scaling Costs

Cloud adoption will drive huge volume of traffic within the datacenter and between the data and its customers. The cost of supporting that traffic must scale at extremely efficient levels. Software-based networking allows a network workload to scale by simply provisioning more of the server, allowing the network to scale at a cost equation similar to a commodity utility. In this way, CapEx can to start at only ~0.25× today and grow in smooth increments (as server resources are released to it) to a maximum cumulative total of only 1× in a year. This translates to a 10× CapEx advantage for software-based networking, an advantage that compounds with each upgrade cycle. As a result, clouds that embrace software-based networking will quickly gain strategic advantage through a radically more cost-effective network scaling model.

High Utilization Rates

In late 2009 Amazon published that their data center servers comprise 45% of the total IT cost and consume 55% of the power—yet their average server utilization is only 10–30% due to limitations caused by traditional proprietary networking infrastructure. In other words, old-style networking causes the single most expensive asset in a cloud data center to be more than 2/3 unutilized. Given that one of the primary business requirements for cloud is extraordinary efficiency, this is clearly unacceptable.

Usage-Based Pricing Models

Software-based networking eliminates the high upfront costs of traditional networking gear, and instead leverages existing server infrastructure. It also enables easy on-demand service capabilities such as increasing or decreasing network service levels. These advantages can be leveraged by engaging with the networking software vendor on a cloud-based licensing model. This can create exceptional financial opportunities for cloud vendors. At its most simple level, volume license agreements can create a foundation for constantly lower variable cost per customer. These benefits continue to compound as the cloud gains in size, underwriting a “scale-based” business benefit for the cloud vendor.

Taking this one step further, Service Provider licensing models are available which allow the cloud provider to synchronize license payments with their pricing models to users. By spreading costs over the duration of the customer contract, the cloud vendor’s financial performance gains the large benefits of a variable-cost infrastructure model. At more involved levels, utility-based pricing can also be established with flexible software vendors. For cloud providers employing highly granular usage-based pricing, it is possible to create similar usage-based licensing structures with software-based networking vendors


There is tremendous excitement in SDN. You might be tempted to ignore SDN, but this newly emerging technology has the potential to completely change the networking landscape. The benefits promised by SDN create real value to customers, which is a clear indication that SDN offers a real revolution in networking, not just exaggerated hype. For cloud providers, software-based networking offers tremendous and market disrupting business advantages. Those who embrace these advantages early will gain the most over time.

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