NFV Basic overview

Reprint an article ：NFV Basic overview

NFV Introduce

Definition

NFV, Virtualization of network functions ,Network Function Virtualization. By using x86 And virtualization technology , To carry many functions of software processing . So as to reduce the network expensive equipment cost . Through hardware and software decoupling and function abstraction , Make the network device function no longer depend on dedicated hardware , Resources can be shared flexibly , Realize the rapid development and deployment of new business , And automatically deploy based on actual business requirements 、 Stretch and stretch 、 Fault isolation and self-healing .

The goal is

NFV The goal of is to replace private in communication networks 、 Dedicated and closed network elements , Realize unified general hardware platform + Open architecture of business logic software .

NFV And SDN Combined use will have a significant impact on the development of future communication networks , It also brings new problems and challenges .

Reasons for development

• Network operators' networks are usually composed of a large and rapidly growing variety of hardware devices . Developing a new network service often requires new types of equipment , And finding space for these boxes 、 Providing power is becoming more and more difficult ; At the same time, it is accompanied by the increase of energy costs 、 The challenge of investment , Based on the complexity of hardware devices , Also added to the design 、 Integrate 、 Requirements for various rare skills required for operation .
• The more serious problem is , Hardware based devices are fast approaching their lifecycle , It takes more “ Design - Integrate - Deploy ” loop , But the benefits are small . Bad is , The hardware life cycle is becoming shorter and shorter, while business innovation is accelerating , So this inhibits the deployment of new value-added services , It also limits innovation in the growing network centric field .
• Network virtualization through borrowing IT Virtualization technology , Many types of network device types can be incorporated into industry standards , Such as servers、switches and storage, It can be deployed in the data center 、 Network nodes or users' homes . Network virtualization applies to fixed 、 Packet processing and control plane functions of any data plane in the mobile network .

From the enterprise 、 Operator, 、 The needs of home users

• With the continuous development of cloud services and the increasing demand , Operators only need to provide pipeline transmission for enterprise private cloud and public cloud , Therefore, operators have the risk of being pipelined .
• Home users do not support multi screen applications in terms of experience 、 Outdoor application , Long service opening cycle , It's expensive .
• Enterprise users need high IT Invest in buying a lot of communication equipment （ Router 、 Switch 、 The server 、 The storage device ）.
• The system expansion requires updating the equipment , Reinvestment .
• CPE（customer premises equipment） Most of them are enterprise network gateways , Connect with the operators PE equipment .

NFV Basic concepts

What is? NFV

NFV Virtualization of network functions （Network Functions Virtualization）, Many types of network devices （ Such as servers,switches and storage etc. ） Build into a Data Center Network, By borrowing IT The virtualization technology of forms VM（ virtual machine ,Virtual Machine）, Then the traditional CT(Communication Technology) Business deployment to VM On .

stay NFV The specialization of equipment was very prominent before it appeared , Specific equipment has its special function realization , After that, the control plane of the equipment is separated from the specific equipment , The control planes of different devices are based on virtual machines , Virtual machines are based on cloud operating systems , In this way, when enterprises need to deploy new businesses, they only need to create corresponding virtual machines on the open virtual machine platform , Then install the corresponding software package on the virtual machine . This approach is called network function virtualization .

Advantages and challenges of network function virtualization

Advantages of network function virtualization ：

1. Merge through devices 、 To borrow IT Economies of scale , Reduce equipment costs 、 Energy costs .
2. Shorten the business innovation cycle of network operation , Improve the speed of putting on the market , It is the operators that greatly reduce the network maturity cycle .
3. Network devices can have multiple versions 、 Multi tenant coexistence , And a single platform for different applications 、 user 、 Tenants provide services , Allow operators to share resources across services and across different customer groups .
4. Based on geographical location 、 Introduce precise services to the user base , At the same time, the service can be expanded rapidly according to the needs / shrinkage .
5. More broadly 、 Diverse ecosystems enable , Promoting openness , Open virtual devices to pure software developers 、 Small businesses 、 academic circle , Encourage more innovation , Introduce new business , Lower risk leads to new revenue growth .

NFV There are also many technical challenges

1. Virtual network devices run in different hardware manufacturers 、 Different Hypervisor On , How to get higher performance .
2. Network platform based hardware also allows migration to virtualized network platforms , Both can coexist , Reuse operators' current OSS/BSS.
3. Manage and organize many virtual network devices （ Especially the management system ）, At the same time, avoid security attacks and misconfiguration .
4. Ensure a certain level of hardware 、 Software reliability .
5. Virtual devices from different operators （VA） Integrate . Network operators need to be able to “ Mix and match ” Hardware from different manufacturers 、 From different manufacturers Hypervisors、 Virtual devices from different manufacturers （VA）, Without huge integration costs 、 Avoid binding with manufacturers .

NFV framework

NFV The essence ： Redefine network device architecture

Huawei CloudEdge The scheme includes four levels and the corresponding highlights are as follows ：

• Software application layer ： Huawei provides rich and complete telecommunication service applications , And open to third parties , Accelerate business innovation and deployment .
• Virtual level Cloud OS： Realize efficient utilization of equipment resources and rapid deployment of business .
• Automatically maintain management MANO (Management And Network Orchestration)： Automatic network scaling , To simplify the management .
• Hardware device layer ： Highly reliable 、 High performance 、 Multi specification COTS Server, Fully meet the needs of carrier level deployment , And support multi manufacturer COTS Server Deploy .

stay NFV Architecture , The bottom layer is a specific physical device , Server, such as , The storage device , Network devices .

Computing virtualization is virtual machine , Create multiple virtual systems on one server .

Storage virtualization , That is, multiple storage devices are virtualized into one logical storage device .

Network virtualization , That is, the control plane of network equipment is separated from the underlying hardware , Install the control plane of the device on the server virtual machine .

Various service software can be installed at the virtualization device level

NFV Open interface

• NFVI： Provide VNF Operating environment , Including the required hardware and software . Hardware includes computing 、 The Internet 、 Storage resources ; The software mainly includes Hypervisor、 Network controller 、 Storage manager and other tools ,NFVI Virtualize physical resources into virtual resources , for VNF Use .

• VNF： Include VNF and EMS,VNF Network function ,EMS For the unit management system , Yes VNF To configure and manage . In general ,EMS and VNF It's one-to-one .

• VIM：NFVI Management module , Usually run in the corresponding infrastructure site , The main functions include ： The discovery of resources 、 Management and allocation of virtual resources 、 Troubleshooting, etc , by VNF Run provides resource support .

• VNFM：VNF Management module , Mainly for VNF Life cycle of （ Instantiation 、 To configure 、 Shut down, etc ） Control , In general, with VNF One-to-one correspondence .

• NFVO：NS Life cycle management module , Also responsible for coordinating NS、 form NS Of VNFs And carrying each of them VNF Control and management of virtual resources .

• OSS/BSS： Management functions of service providers , Do not belong to NFV Functional components within the framework , but NFVO Need to provide OSS/BSS The interface of .

SDN And NFV The relationship between

1. NFV Do not depend on and SDN, however SDN The separation of data forwarding and control can be improved NFV network performance .
2. SDN It can also be done by using universal hardware SDN The controller and service switch are implemented in the form of virtualization .
3. Conclusion ： With mobile networks ,NFV Is the main architecture of network evolution . In certain scenarios , Will introduce SDN.

SDN And NFV contrast ：

type	SDN	NFV
The main proposition is	Separation of forwarding and control , Control surface centralization , Network programmability	Move the network function from the original dedicated device to the general-purpose device .
	Campus network , Data Center 、 cloud	Operator network
	Commercial servers and switches	Private servers and switches
	Cloud resource scheduling and network	Router 、 A firewall 、 gateway 、CND、 Wan Accelerator 、SLA Promise to wait
General agreement	OpenFlow	Not yet
	ONF（Open Networking Forun） organization	take ETSI NFV Working group

• NFV It's virtualization of specific devices , Run the device control plane on the server , So the device is open and compatible .
• SDN It's a new network architecture ,SDN The idea is to cancel the device control plane , Unified calculation by the controller , Send out the flow meter ,SDN It's a new network architecture .
• NFV and SDN It's a highly complementary relationship , But it's not interdependent . Network functions can be used without SDN Virtualization and deployment , However, the combination of these two ideas and solutions can produce potential 、 Greater value .
• Virtualization of network functions （NFV） The goal is not to SDN Mechanism , Only through current data center technology . But the method depends on SDN Proposed separation of control and data forwarding planes , Can enhance performance 、 Simplify compatibility with existing devices 、 Basic operation and maintenance procedures .
• NFV Can be provided to SDN The way the software runs the infrastructure to support SDN. and ,NFV and SDN Use the basic server in both 、 Switch to achieve the goal , This point is very close .