Applications  are roundly in the spotlight now, with the launch of Cisco Application Centric  Infrastructure (ACI) and the Nexus 9000 solutions.

Citrix has been in the application delivery business for the past two decades; it’s what we’re known for.  Our customers deliver millions of applications – Windows, Web, SaaS or Cloud – to their employees and their customers.  We live with the apps at layers 4-7, riding on the network at layers 1-3.

Applications + Networks

We have been taking steps to bridge the application and networking worlds.  The goal of our proposed collaboration with Cisco is to meet the needs of applications running on Cisco infrastructure.  And if you think about it, delivering applications is what IT is all about.

Our alliance has blossomed over the last few years.  Two years ago, we started with the applications – application and desktop virtualization solutions featuring XenApp & XenDesktop on Cisco UCS.  Our next step is to work closely with Cisco’s Data Center product teams in cloud networking.  We have been working on integrating and embedding our market leading NetScaler application delivery controller with Cisco Nexus 7000 and Nexus 1000V.  With a vPath integration, our mutual customers can chain virtual services across VMs in the data center and Citrix NetScaler appliances are managed seamlessly as service blades in Cisco Nexus infrastructure – more on this later.

What makes this special?

In short, this is another significant step in our journey towards making the infrastructure application-aware. In a typical application deployment today, development and delivery teams have no real ability to control the network, which is largely unaware of the unique needs of applications and unable to offer app-centric services.

But now, with the work our two teams have done together (and propose to continue), Cisco’s ACI architecture with closely integrated application services can become application-aware. This application-centric approach is a foundational enabler of a truly agile, flexible and resource-wise fluid data center.

Let us look at it in some detail.

What is it?

There are two parts to the application-awareness formula:

  • A centralized fabric control and automation framework capable of juggling application policies:  This policy driven automation framework allows resources to be dynamically provisioned and configured based on application requirements.  The result is that core services such as traffic management, application delivery and firewalls can be consumed by applications in a manner that is automated, repeatable, follows-the-app and push-button simple.
  • Application Services:  These are the higher level application centric services such as load balancing, firewalling, advanced optimizations, application firewalls and so on, that live in the network, but have affinity to applications.

A collaboration between Citrix and Cisco can allow the Cisco Application Policy Infrastructure Controller (APIC)  to become the control and automation framework with Citrix NetScaler providing several of the application services.

APIC enables a policy-driven service insertion solution that automates the step of routing network traffic to the right services based on application policies.  The automated addition, removal, and reordering of services allows applications to quickly change without needing to rewire, reconfigure or relocate resources and services.  This is policy that evolves with the application in a topology and location independent fashion.

Citrix NetScaler works in the APIC environment in an integrated manner providing Layer 4-7 services such as load balancing, application acceleration, optimization, and application security.

What does it do?

Put simply, an  integration between NetScaler and Cisco APIC would unify both the management and flow of data through hardware and software in the datacenter.  This makes a number of things possible:

  1. You can automatically insert a service based on application policies.
  2. Network services can now be automated with scripts leveraging open APIs.
  3. You have tight integration of physical and virtual service appliances.
  4. With virtual LAN overlays, massive scale and multi-tenancy can be woven in without any additional special treatment for network services.
  5. You get visibility and statistics across the network and services.

Why does it matter?

This level of tightly integrated application + network infrastructure can be a game changer.

  1. Central point of control – now there is one place in the network to control all of the functions that the network delivers.  Application teams can focus on application policies and the network can manage their provisioning and deployment.
  2. Scalable and Elastic – by decoupling service nodes from service policy, we allow elastic scale with both physical and virtual ADC appliances.
  3. Investment Protection – the integration is designed to be fully compatible with existing NetScaler deployments and deployment models
  4. Open – while the work on this integration is groundbreaking, we are committed to help standardize some of the important innovations that go into it.  As an example, Cisco and Citrix are driving within the IETF to define the Network Service Header (NSH) protocol that supports the fluid movement of both service functions and application workloads within the fabric.

Joining us on the Application + Networking Path

When you adopt the latest and greatest from Citrix and Cisco that are a part of this program, you can be at the cutting edge of this movement.  However, one of the best things about our collaboration activities is that even as we are working together to deliver NetScaler integration with Cisco ACI, we have integrated NetScaler with Nexus 1000V and 7000 already.  These integrations serve as a prelude to fully-managed ACI, bringing the benefits of application-awareness to today’s networks.


In closing, the unification and cross-leverage of the application and infrastructure that we see here brings full centralized policy-driven automation of data flow unified across layers 2-7.  Similarly, a single pane of glass for configuration, policy and visibility offers corresponding unification in the control plane as well.

Exciting times ahead.  Watch for more innovation from Cisco and Citrix.