Network Functions Virtualization (NFV) has resulted in replacing dedicated network appliances - such as routers and firewalls - with software running on commercial off-the-shelf servers. These software or applications running on servers are called as Virtual Network Functions or VNFs.
Based on a recent survey by IHS Infonetics, more than 75% of the respondents rated “increased operational efficiency” as a strong driver for NFV. Flexibility in deploying VNFs (in terms of location of the servers) is a key factor for increased operational efficiency in NFV networks.
Five options are available for the service providers to host their NFV servers.
1. Provider Central Office (CO)
2. Provider Data Center (DC)/Private Cloud
3. Provider Point of Presence (POP)
4. Enterprise Head Office (HO)
5. Enterprise Branch Office (BO)
A more pragmatic approach is a distributed deployment model where some of the VNFs are running on servers at the Enterprise HO/BO whereas some others at service provider CO or POP or DC. For example, in the case of an Enterprise vCPE, the data plane functions such as NAT, QoS, etc. are deployed at Enterprise HO/BO (Distributed Data Plane). Meanwhile, the control plane functions such as DNS, DHCP, etc. are deployed at a service provider CO or POP or DC (Centralized Control Plane). Distributed deployment of VNFs brings in the advantages of network offloading capability, reduced latency & jitter considerations, higher reliability & availability and improved security.