Network Functions Virtualization: Don’t Fence Me In

Oct 22, 2014

Network Functions Virtualization (NFV) offers the promise of reducing cost and increasing innovation by bringing the power of the cloud to the network.  One aspect of NFV is the decoupling and separation of hardware and software, and separation of functions from appliances.  Why discard the power of separation by keeping the virtualized functions fenced inside a data center?

Put the Functions Where They are Needed
In many cases it makes sense to put virtual network functions (VNFs) in a datacenter where they may be used to realize economies of scale.  Especially for functions like virtual CPE (vCPE), it is efficient to use large servers to provide many functions for multiple customers and services.  This was the scenario envisioned in the original ETSI NVF white paper.

However, some VNFs may need to reside at the customer site, even if they are virtualized.  An example would be any VNFs associated with security where packets need to be protected before they leave the customer site.  Otherwise they might be subject to interception on the access link, and that is not acceptable for some customers.

Here are some other examples that are associated with topology:

  • WAN Optimization and Content Caching, especially for low-speed access links.  The optimization functions must occur at the customer site in order to realize the benefits.
  • Dual-home routing. The routing function must reside on the customer site.  This is because a local routing decision must be made in failover scenarios.
  • SLA Monitoring.  This includes both network performance as well as Quality of Experience.
  • Diagnostics.  This VNF might be temporarily instantiated on the customer site as a part of a trouble-shooting process.
  • Cloud Storage Gateway, which optimizes the performance and security of cloud services.

Finally, a VNF may be providing a function that must continue even if the access link is lost.  Examples of this include wireless controllers and authentication servers.

Support Existing Deployment Models Where Appropriate
The scenarios described above are all related to services whose operation requires VNF functionality at the site where the service originates.  A less obvious reason to locate functions there is that it fits with existing service implementation and operational models.

Operators know that they need to change the way that they create and deploy services, moving to include aspects of DevOps, agile methodologies and cloud technologies.  However, these changes can’t occur instantaneously.   Providing a means to implement services with VNFs at the customer site provides a means to gracefully transition to a virtualized world, realizing the benefits without having to make a step change in methodology.

Don’t Limit Innovation!
The final and best reason for supporting virtualization at the edge of the network is that it provides a platform for innovation.  As I have written elsewhere, the most valuable innovations are the ones that we haven’t thought of.  These future innovations will be enables by creating a platform that allows efficient service delivery today with a means for supporting those yet-to-be discovered future services.

Bring the Cloud to the Customer
Overture and other suppliers are providing interesting new platforms that support deploying VNFs at the on ramp to the cloud.  These platforms combine the best of carrier-class physical features with the flexibility of an open server platforms. You can read more about Overture’s offering here.

About the Author
Prayson Pate is Chief Technology Officer and SVP of R&D at Overture, where he is also a co-founder. Prayson is a technology leader and evangelist with a proven track record leading teams and delivering products. Since 1983 he has been building Carrier Ethernet and telecom products for service providers and network operators around the world – both as an individual developer and as a leader of development teams. Prayson spends much of his time driving adoption of Overture’s new Ensemble Open Service Architecture, which includes aspects of automation, virtualization, SDN and NFV. He has a BSEE from Duke, an MSECE from NC State and is the holder of nine US patents.

Network Functions Virtualization: Don’t Fence Me In was last modified: June 30th, 2015 by Prayson Pate

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