The impact of OpenFlow on Network Innovation

Because the current network has exposed more and more disadvantages and people's demand for network performance has improved, researchers have to add many complex functions to the architecture of routers, such as OSPF, BGP, multicast, differentiated services, traffic engineering, NAT, firewall, MPLS, and so on. This makes vrouters and Other switching devices more and more bloated and the space for performance improvement is getting smaller and smaller.

However, unlike the network field, the computer field has developed rapidly. Looking back at the development of the computer field, it is not difficult to find that the key is that the computer field has found a simple and available underlying hardware (x86 instruction set ). With such a public hardware underlying layer, both applications and operating systems have developed rapidly in terms of software. Many people who advocate re-designing the computer network architecture believe that the network can successfully replicate the computer field to solve all the problems encountered by the network. Under the guidance of this idea, the future network will surely be like this: the underlying data path switches and routers are "dumb, simple, and minimal ", it also defines an open public API for streaming tables, and uses controllers to control the entire network. In the future, researchers will be able to freely call the underlying API on the Controller for programming, so as to realize network innovation.

OpenFlow is a powerful promoter of this network innovation idea. The OpenFlow Switch converts the packet forwarding process completely controlled by the Switch/router into the OpenFlow Switch of the OpenFlow Switch) and the Controller of the control server, this separates data forwarding from route control. The controller can control the flow table in the OpenFlow switch through the interface operations specified in advance, so as to control data forwarding.

Therefore, OpenFlow has opened up a path for network innovation. If OpenFlow is widely used and popularized, the network in the future will develop rapidly like computers.

A stream table consists of multiple table items. Each table item is a forwarding rule. The data packet that enters the vswitch retrieves the destination port for forwarding by querying the stream table. A stream table item consists of a header field, a counter, and an operation. the header field is a ten-element group and identifies a stream table item. The counter is used to count the statistical data of a stream table item; the operation indicates the operation that the data packet that matches the current table item should be performed.