Most enterprise customers have connectivity to the cloud for IaaS, SaaS or PaaS services. The cloud offers enterprise customers many benefits. It is very common for an enterprise to adopt cloud-based services to
- Be agile
- On demand services for computing resources
- Reduction in CAPEX
Enterprise architects prefer having control of the services in their tenant space within the cloud infrastructure. The concept of network function virtualization (NFV) comes up here. NFV elements are prevalent in IaaS cloud services. NFV brings a simple concept of implementing network service elements such as routing load balancers, VPN services, WAN optimization, and firewalls, in software. This is possible due to the new capability of provisioning memory and server facility to the network service elements. The NFV elements can be automated enabling faster provisioning of service. These virtual services enable an enterprise to have these network functions on an on-premises data center, in the provider cloud, or at a branch location.
NFV offers new ways to design, orchestrate, and manage network services. NFV decouples network functions from underlying hardware so these functions can run as software images on commodity hardware as well as custom-built hardware. NFV is a framework that provides virtualization of network services such as routing, load balancing, firewall services, intrusion detection and prevention, and network address translation into building blocks. These services can be chained together to create network service chains tailored for different use cases.
The concept of NFV originated from service providers looking to increase the agility and flexibility of deploying new network services to support growing customer demands. NFV is complementary to SDN, and there is no dependency between SDN and NFV. NFV can be implemented using non-SDN mechanism leveraging techniques commonly deployed in many data centers. However, combining SDN with NFV simplifies deployment, operation and maintenance procedures.
CSR 1000V as a Virtual Network Function
The evolution of orchestration and management for NFV technology helps network architects leverage NFV technology to meet the same network requirements within a single box rather than using multiple dedicated appliances. The maturing of orchestration technology and availability of software footprint of IOS-XE (CSR 1000V) has increased the adoption of virtual networking functions in the enterprise.
You will hear the terms NFV and VNF (Virtual Network Functions) interchangeably sometimes. However, there is a subtle difference. NFV is a complete virtual service paradigm, while VNF is an element that is part of the NFV framework.
The use of the CSR 1000V removes the need for dedicated routing hardware, and a complete suite of NFV elements can replace IT service functionality needed at the branch. Cisco has various options to orchestrate and automate these virtual instances using Network Service Orchestrator and Enterprise Service Automation engine (APIC-EM).
Below are the use cases within the enterprise for CSR 1000V:
- vBranch
- Route reflector
- LISP xTR
- VPN Gateway
The adoption of CSR 1000V for these use cases has helped the enterprise to scale and optimize their CAPEX investment. The extension of enterprise has resulted in an increase in demand for enterprise features in the cloud, such as:
- DMVPN
- Performance routing (PFR)
- IPSEC
- Firewall functionality
- NAT
- LISP
- VxLAN
Virtual Branch Solution
The NFV approach to branch virtualization opens up new technology avenues by providing a platform for customers to deploy virtualized network elements as required. Coupling this with an easy-to-use end-to-end orchestration and management framework, enterprises are able to significantly reduce costs and get better return on investment (ROI) by avoiding expensive truck rolls to enable services at their branches. These are the key aspects of branch virtualization:
- Programmability—You can leverage open APIs to enable better automation of network services while improving visibility.
- Agility—You gain flexibility in deploying services quickly in a timely manner. You can improve business efficiency in capital and operations by meeting the evolving business requirements, including traffic growth, diversity of traffic types, performance, reliability demands, and expectations.
- Simplicity—You can reduce complexity from services and operations and endorse more nimble business models. You gain the ability to manage all branches with a single pane of glass.
Branch virtualization leverages a specialized platform customized to take care of NFV requirements and offload special functions, such as encryption and customized drivers, to provide increased performance for different NFV elements. NFVs and VNFs are the foundation blocks for the next-generation networking gear:
- Customized x86 hardware to host VNF elements
- Optimized hypervisor platform to launch VNF elements
- Solid foundation of orchestration engine
- Flexible options for I/O
Conclusion
NFV enables on-demand service and centralized orchestration for integrating the new service into the existing ones—in essence creating a service chain. For example, a customer who desires firewall functionality can use a portal to choose among a list of VNFs (ASAv, vWAAS, and so on), which will then be deployed dynamically on the platform. Enterprises gain the ability to choose "best of breed" VNFs to implement a particular service. By using NFV, you can spawn virtual devices to scale to new feature requirements. For example, the branch router has a security gateway (firewall and Sourcefire) that provides functionalities such as firewall services, Advanced Malware Protection (AMP), Application Visibility and Control (AVC), and URL filtering. Instead of using firewall functionality in the router, you have an option of using an NFV element that provides additional security functionality.