#SDN #ADN #cloud #devops What does that mean, anyway?
SDN and devops share some common themes. Both focus heavily on the notion of programmability in network devices as a means to achieve specific goals. For SDN it’s flexibility and rapid adaptation to changes in the network. For devops, it’s more a focus on the ability to treat “infrastructure as code” as a way to integrate into automated deployment processes.
Each of these notions is just different enough to mean that systems supporting one don’t automatically support the other. An API focused on management or configuration doesn’t necessarily provide the flexibility of execution exhorted by SDN proponents as a significant benefit to organizations. And vice-versa.
Devops is a verb, it’s something you do. Optimizing application deployment lifecycle processes is a primary focus, and to do that many would say you must treat “infrastructure as code.” Doing so enables integration and automation of deployment processes (including configuration and integration) that enables operations to scale along with the environment and demand.
The result is automated best practices, the codification of policy and process that assures repeatable, consistent and successful application deployments.
F5 supports the notion (and has since 2003 or so) of infrastructure as code in two ways:
Infrastructure as code is an increasingly important view to take of the provisioning and deployment processes for network and application delivery services as they enable more consistent, accurate policy configuration and deployment. Consider research from Dimension Data that found “total number of configuration violations per device has increased from 29 to 43 year over year -- and that the number of security-related configuration errors (such as AAA Authentication, Route Maps and ACLS, Radius and TACACS+) also increased. AAA Authentication errors in particular jumped from 9.3 per device to 13.6, making it the most frequently occurring policy violation.” The ability to automate a known “good” configuration and policy when deploying application and network services can decrease the risk of these violations and ensure a more consistent, stable (and ultimately secure) network environment.
Less with “infrastructure as a code” (devops) and more-so with SDN comes the notion of programmability. On the one hand, this notion squares well with the “infrastructure as code” concept, as it requires infrastructure to be enabled in such as a way as to provide the means to modify behavior at run time, most often through support for a common standard (OpenFlow is the darling standard du jour for SDN). For SDN, this tends to focus on the forwarding information base (FIB) but broader applicability has been noted at times, and no doubt will continue to gain traction.
The ability to “tinker” with emerging and experimental protocols, for example, is one application of programmability of the network. Rather than wait for vendor support, it is proposed that organizations can deploy and test support for emerging protocols through OpenFlow enabled networks. While this capability is likely not really something large production networks would undertake, still, the notion that emerging protocols could be supported on-demand, rather than on a vendor' driven timeline, is often desirable. Consider support for SIP, before UCS became nearly ubiquitous in enterprise networks. SIP is a message-based protocol, requiring deep content inspection (DCI) capabilities to extract AVP codes as a means to determine routing to specific services. Long before SIP was natively supported by BIG-IP, it was supported via iRules, F5’s event-driven network-side scripting language. iRules enabled customers requiring support for SIP (for load balancing and high-availability architectures) to program the network by intercepting, inspecting, and ultimately routing based on the AVP codes in SIP payloads. Over time, this functionality was productized and became a natively supported protocol on the BIG-IP platform.
Similarly, iRules enables a wide variety of dynamism in application routing and control by providing a robust environment in which to programmatically determine which flows should be directed where, and how. Leveraging programmability in conjunction with DCI affords organizations the flexibility to do – or do not – as they so desire, without requiring them to wait for hot fixes, new releases, or new products.
The very same trends driving SDN at layer 2-3 are the same that have been driving ADN (application delivery networking) for nearly a decade.
Five trends in network are driving the transition to software defined networking and programmability.
• User, device and application mobility;
• Cloud computing and service;
• Consumerization of IT;
• Changing traffic patterns within data centers;
• And agile service delivery.
The trends stretch across multiple markets, including enterprise, service provider, cloud provider, massively scalable data centers -- like those found at Google, Facebook, Amazon, etc. -- and academia/research. And they require dynamic network adaptability and flexibility and scale, with reduced cost, complexity and increasing vendor independence, proponents say.
Each of these trends applies equally to the higher layers of the networking stack, and are addressed by a fully programmable ADN platform like BIG-IP. Mobile mediation, cloud access brokers, cloud bursting and balancing, context-aware access policies, granular traffic control and steering, and a service-enabled approach to application delivery are all part and parcel of an ADN.