Virtualization - Network Functions Virtualization

10 important questions on Virtualization - Network Functions Virtualization

What does the NFVI Virtualized Infrastructure Manager (VIM) do?

It is responsible for managing and controlling the NFVI hardware resources and virtualized resources
As well as Service Chaining, which is the process of chaining VNFs together to provide an NFV service or solution.

What are Element Managers (EMs)?

Also known as Element Management Systems, they are responsible for the FCAPS tasks for the VNFs (fault, configuration, accounting, performance and security)

What are 3 I/O technologies that are used to bypass the CPU for network processing?

1. OVS Data Plane Development Kit (OVS-DPDK)
2. PCI passthrough
3. Single-root I/O virtualization (SR-IOV)
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How does OVS-DPDK work?

It runs entirely in the User Space and uses the DPDK Poll Mode Driver to poll for incoming data into the pNIC.
Because it is then already in the User Space it can be directly switched to the VNF.

How does PCI Passthrough work?

PCI Passthrough allows a VNF direct access to physical PCI device as if it was physically attached to the VNF.
Because of this the physical device is dedicated to the single VNF.

How does SR-IOV work?

It is an enhancement to PCI passthrough. It emulates multiple PCIe devices on a single PCIe deivce.
The emulated PCIe devices are called Virtual Functions (VFs)
And the physical PCIe devices are called Physical Functions (PFs)

What two modes does an SR-IOV enabled physical NIC support for switching traffic between VNFs?

1. Virtual Ethernet Bridge (VEB) (Traffic between VNFs attached to the same pNIC is hardware switched directly by the pNIC)

2. Virtual Ethernet Port Aggregator (VEPA) (Traffic between VNFs attached to the same pNIC is switched by an external switch)

What is Cisco Enterprise Network Functions Virtualization (ENFV)

A Cisco solution that runs different network functions as Virtual Network Functions on a single or a few x86-based hosts.
Managed through Cisco DNA Center

What 4 components, based on the ETSI NFV architectural framework, does the Cisco ENFV solution architecture consist of?

1. Management and Orchestration (MANO) (Cisco DNA Center for management and orchestration  of VNFs and Network Services)

2. VNFs (Virtual Network Functions)

3. Network Functions Virtualization Infrastructure Software (NFVIS) An Operations System that provides virtualization capabilities.

4. Hardware resources (x86-based computer resources)

What Cisco x86 based platforms can Cisco Enterprise NFVIS be hosted on?

1. Cisco Enterprise Network Compute System (ENCS)
2. Cisco Cloud Services Platforms
3. Cisco 4000 series ISRs with a Cisco UCS E-Series blade
4. UCS C Series

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