1 ODL诞生的原因分析
2 ODL主要目标介绍和分析
3 ONF和ODL的比较
4 ONF和ODL的利益冲突
5 ODL内部利益之争及Big Switch的退出
6 OpenDayLight系统架构
ODL reason for the birth of the analysis
in April 2013 by 18 leading IT vendors launched OpenDayLight organization was formally established, it is not ODL SDN standards organization, but a SDN promote development and achieve an open source SDN controller organization, and does not develop standards. Most of these 18 companies are American companies, Internet companies accounted for half are BigSwitch, Brocade, cisco, Citrix, Ericsson, IBM, Juniper, Microsoft, redhat, NEC, vmware, arista, Dell, Fujitsu, HP, Intel , nuagenetworks and plumgrid.
Learning from history, the history of the network whenever there are major technological birth, all manufacturers want to divide a piece of big manufacturers also true, and large companies must not only meet the ambitions as a follower, but hope that when the leader, by to actively participate in the development of technology around. At this point, cisco than any other big companies have shown more intense, not just excuse for technical reasons, in the interests of ODL and two technical levels have enough motivation to analyze these two aspects of the birth of ODL:
interest levels: ONF is a user-initiated organization, and the board of directors without exception, are network equipment users, and they made SDN SDN pushing one of the motivations is to prevent vendor lock-in, can be used to lift the SDN is undoubtedly a strong vendor lock-in means. Control Panel software and user controlled, forwarding plane interface is open, but ONF also pushing forward the standardization of equipment behavior, the threat for large manufacturers is fatal, if not all devices so play, but it certainly is that the largest shipments of low-end equipment, so manufacturers can not let this situation develop. In addition, even if the ONF's OpenFlow good, but the standard-setter which did not participate in large companies, they are just like everyone else a follower and users, this is absolutely intolerable, this is the level of interest ODL established reasons .
The technical level: ONF in a user-defined standard point of view, definitely bring a lot of things beneficial to users, but found throughout OpenFlow standard, this is a very idealized standard, is only semi-finished products, so whether existing or based controller OpenFlow switches are not large-scale commercial, just an experimental product, if ONF rely on their own staff to complete this standard, no vendor involvement, there will be a very long time, which is the reason for the establishment of the technical aspects of ODL.
ODL The main goal of introduction and analysis
to create an open source platform based SDN framework, including network applications and services from top to bottom, northbound interface, pay attention to the interface, the central controller platform, the south, the platform does not include the forwarding plane, in addition to NBI other all levels are allowed to expand outside of the standard, which is a large-scale open source project, after setting up the framework to allow all developers on the basis of secondary development, in other words, it is to create a network operation system.
South of this system includes an interface to many types of interfaces, OpenFlow is one of them, that is to say OpenDayLight system to create controller is a superset of the OpenFlow controller, the controller becomes SDN controller, and the controller only supports OpenFlow OpenFlow become controller.
This is a large software project, involving a lot of coding to achieve the organization provides that each member organization to pay certain amount of money each year based on membership levels, and to implement the human resources involved in the project, each company has different emphases on the division of labor , for example, cisco and big switch to provide development SDN controller technology and program code, IBM will open source version of network virtualization technology Dove submission, while redhat SDN solutions will work with OpenStack, KVM virtual platform, linux systems integration Wait.
Comparison of the ONF and ODL
ONF of conflict of interest and ODL
from comparative point of view, ONF and ODL is actually two parallel organizations, there is overlap between the two, but more of a difference, ONF specify the OpenFlow standard, but not just to achieve the OpenFlow ODL a standard, to achieve much more than OpenFlow, and some inside and OpenFlow is in conflict, such as ODL forwarding plane does not assume that there is a unified standard, but do not assume forwarding plane is protocol-independent, especially manufacturers run custom interface.
In fact, the core difference between the two organizations:
ONF think SDN southbound interface need to be standardized, push the standardization program is OpenFlow, and the ODL do not think so, they believe that the core is the master SDN and forwarding separation, southbound interface allows the flourishing It does not require standardization.
ONF standing web user's perspective, hoping to rid itself of vendor lock-in, so certainly hope that all the interfaces are standardized interface hardware is standardized hardware, and different equipment manufacturers led by ODL, on the one hand SDN consider this industry can push forward, it requires a certain degree of standardization, but on the other hand, retained the vendor-specific rights, leaving manufacturers to allow customization of the interface, either south or north to the interface. Particularly undesirable standardization of hardware, such as the future of customized hardware manufacturers to leave room.
ODL internal dispute and the interests of the Big Switch to exit
commercial companies unconditionally pay for open source projects that are basic things will not happen, but the above mentioned and why? cisco's OnePK, IBM's DOVE, Redware security defense system, NEC's virtual tenent network, are their core business technology, they contribute out why?
OpenDayLight is a very likely be extended to open-source controller systems around the world, it might become a mainstream controller is widely used, but its architecture and built to allow some services and applications. So a company's service or application if placed ODL go inside, it would not be accompanied by ODL mean to the world is familiar with many users? Some people may think that open source code, the company how to make money, it is not true, we often use the software in a foreign country when there is a lot of software is shareware, and if you try to share the benefits of version, when you want to use some advanced features, They have to pay for. ODL behind the same is true, open source code, only basic functions, as a number of value-added services, such as firewalls, no. So if you use ODL, access to certain services inside, feel good, then you must buy their commercial version OpenDayLight to specific companies.
It is because of this, we all want to own things into ODL to go inside, but also between the company is competing, which all want ODL infrastructure more in line with its own architecture. ODL has set up a technical decision-making committee, responsible for some of the key technical decisions, ODL member companies are trying to let one of us go in, leading to fierce internal struggles, factions serious. Big Switch is the victim of an internal struggle.
Big Switch is accompanied by one of SDN and the rise of well-known companies, is SDN / OpenFlow hardcore advocates, both ONF member companies, is one of 18 companies ODL, ODL beginning of the establishment, Big Switch was given a cisco together with the contribution of important task controller code. Big Switch for a relatively mature own controller, called floodlight, is a pure OpenFlow controller; and cisco owns a ciscoonne the controller is called, which has an interface, there are some things more private south.
Although ODL mind is good, with the contribution to the new controller code, but because of the companies controller framework very different, so be sure to choose one of them as the basis of the results of cisco win, so Big Switch quit, announced its withdrawal from ODL.
OpenDayLight system architecture
after the Big Switch quit, ODL controller architecture is naturally grasp cisco, finally adopted Cisco OnePK architecture, as shown:
The ODL platform to build the system architecture, both repeat itself similar
OpenDayLight this system includes three parts, the top northbound interface and built-in applications and services, in the middle of the core network and platform services, the lowest level for the southbound interface.
NBI uses the very popular REST API interfaces, it can be very flexible to support a variety of applications. REST in recent years the most influential Web services design patterns. Sina micro-channel support REST interface. In addition to the participant user interface, OpenDayLight projects contributed a lot of their own applications and platform services, such as anti-DDOS attacks applications, virtual tenant network VTN, distributed overlay virtual Ethernet DOVE, network virtualization platform NVP.
Southbound interfaces including OpenFlow and other interfaces, OpenFlow is just a small part of this platform, the South the figure is not listed in the interfaces as well as SNMP LISP XMPP PCEP OF-Config, etc., also allows vendors to define the private interface.
OpenDayLight evident ambition, which is to create a take-all network operating system, not just a OpenFlow controller, to the south beyond the OpenFlow interface to reveal a fact: not just run on the switch forwarding software, as can have an agreement in operation, but the configuration of the agreement, by the local controller rather than the command line to complete. In this sense, OpenDayLight SDN is considered the essence of the management plane and forwarding plane separation, and protocol control plane can face together with management, it can also be forwarded together with the surface.
Chart can be seen by large manufacturers ODL project to achieve two objectives:
to promote the development of SDN;
completion of a defensive battle.
