WO2016034217A1

WO2016034217A1 - Software defined networking controller for hybrid network components and method for controlling a software defined network

Info

Publication number: WO2016034217A1
Application number: PCT/EP2014/068710
Authority: WO
Inventors: Israel ZIV
Original assignee: Huawei Technologies Co.,Ltd.
Priority date: 2014-09-03
Filing date: 2014-09-03
Publication date: 2016-03-10
Also published as: CN105580315A

Abstract

A software defined networking controller (2) comprises a communication unit (3) configured to communicate with network components (5) and a control unit (4). The network components (5) comprise at least one hybrid network component (5) comprising at least one software defined networking compliant network resource (6), and at least one non-software defined networking compliant network resource (7). The control unit (4) is configured to control the at least one software defined networking compliant network resource (6) and the at least one non-software defined networking compliant resource (7).

Description

Software defined networking controller for hybrid network components and method for controlling a software defined network

TECHNICAL FIELD

The invention relates to a software defined networking controller for controlling network components, especially hybrid network components in a software defined network and an according method.

BACKGROUND

During recent years, software defined networking has steeply risen in importance. At present, software defined networking controllers are used for controlling software defined networking compliant network components. Legacy networking controllers are used for controlling non-software defined networking compliant network components. For controlling software defined networking compliant network components and non- software defined networking compliant network components, it is necessary to have different networking controllers. This leads to a high hardware effort and a high implementation effort for network migration.

SUMMARY Accordingly, the object of the present invention is to provide a software defined networking controller and method for controlling a software defined network, which are able to control a wide variety of network components while incurring a low hardware and labor cost for implementation. The object is solved by the features of claim 1 for the device and by the features of claim 14 for the method. Further it is solved by the features of claim 15 for the associated computer program. The dependent claims contain further developments.

A first aspect of the present invention provides a software defined networking controller comprising a communication unit configured to communicate with network components and a control unit. The network components comprise at least one hybrid network component comprising at least one software defined networking compliant network resource (SDN compliant network resource), and at least one non-software defined networking compliant network resource (non-SDN compliant network resource). The control unit is configured to control the at least one software defined networking compliant network resource and the at least one non-software defined networking compliant resource. It is therefore possible to control individual network resources of a hybrid network component no matter, if they are SDN compliant or non- SDN compliant by a single software defined networking controller. Very low hardware and implementation manpower costs are therefore incurred.

According to a first implementation form of the first aspect, the communication unit is configured to receive information regarding said network resources of said hybrid network component. The software defining networking controller then further comprises a databank for storing said received information. The control unit is then furthermore configured to control said network resources of said hybrid network component based upon said stored information. A very flexible configuration of the software defined network is thereby possible. According to a second implementation form of the first aspect, said information indicates, whether a respective network resource of said hybrid network component is an SDN compliant network resource or a non-SDN compliant network resource. The SDN controller can thereby easily judge how to control the individual network resource. This furthermore reduces the implementation effort.

According to a third implementation form of the first aspect, said at least one SDN compliant network resource is a software defined networking queue or a software defined networking flow. Alternatively, according to a fourth implementation form, the at least one SDN compliant network resource is an SDN compliant network port. In this case, the at least one non-SDN compliant network resource is a non-SDN compliant network port. A very wide variety of different network resources can thereby be controlled by the software defined networking controller. According to a fifth implementation form of the first aspect, the control unit is configured to control the at least one SDN compliant network port and the at least one non-SDN compliant network port to route incoming packets at these network ports to further network ports of said hybrid network component. A very flexible use of the network resources is thereby possible.

According to a sixth implementation form of the first aspect, the at least one SDN compliant network port is an openflow controlled port. By using the openflow standard, a very easy implementation can be achieved.

According to a seventh implementation form of the first aspect, the control unit is configured to control the SDN compliant network resources and non-SDN compliant network resources of the network components based on a data model including an abstract device entity for each network component controlled by the control unit. The abstract device entities each contain a number of abstract resource entities which in turn comprise abstract network ports or abstract network queues or abstract network flows. The resource entities each point to a specific implementation of a resource. The specific implementations of resources comprise network ports, network queues and network flows. By using such a data model, a very efficient implementation is possible.

According to an eighth implementation form of the first aspect, the communication unit is configured to, upon connection with a given network component, receive information from the given network component, the information regarding the network resources available at the given network component. The control unit is then configured to, based on the received information, create an abstract device entity for the given network component in the data model. Parts of the implementation can therefore be automated, further reducing the implementation effort. According to a ninth implementation form of the first aspect, the hybrid network components are hybrid network switches or hybrid network routers comprising at least one SDN compliant port and at least one non-SDN compliant port. Especially by use of hybrid network switches and hybrid network routers as hybrid network components, a large part of the overall hybrid network components are covered. For this large part of the available hybrid network components, the reduced implementation effort can be achieved.

According to a tenth implementation form of the first aspect of the present invention, a software defined networking system is provided. The SDN system comprises a software defined networking controller as described above, a management controller, and at least two network components. The management controller is configured to control the software defined networking controller by issuing route request to the software defined network controller. A high efficiency of implementation can thereby be reached.

According to an eleventh implementation form of the first aspect, said route requests each comprise two of said network components, a dataflow is to be initiated or terminated between. The managing controller therefore does not have to comprise detailed knowledge about the setup of the software defined network. This further increases efficiency.

According to a twelfth implementation form of the first aspect, the software defined networking controller comprises at least an SDN compliant network port and a non- SDN compliant network port. The software defined network controller is then configured to initiate or terminate connections between said network ports of said at least one hybrid network component and network ports of said network components to initiate or terminate the above-mentioned data flow specified by the route request. A very efficient management of the software defined network is thereby achieved.

According to a second aspect of the invention, a method for controlling a software defined network using a software defined networking controller is provided. The software defined network comprises the software defined networking controller and network components comprising at least one hybrid network component. The at least one hybrid network component comprises at least one SDN compliant network resource and at least one non-SDN compliant network resource. The software defined networking controller controls the at least one SDN compliant network resource and the at least one non-SDN compliant network resource. A low implementation effort and high management efficiency can thereby be achieved. According to a first implementation form of the second aspect of the present invention, information regarding said network resources of said hybrid network component are received and stored in a databank of the software defined networking controller. For controlling the network resources of said hybrid network component, the stored information is used. A very flexible control of the resources is thereby possible.

According to a second implementation form of the second aspect, said information indicated whether a respective network resource of said hybrid network component is an SDN compliant network resource or a non-SDN compliant network resource. A very flexible configuration of the software defined network is thereby possible.

According to a third implementation form of the second aspect, said at least one SDN compliant network resource is a software defined networking queue or software defined networking flow. According to a fourth implementation form, said at least one SDN compliant network resource is an SDN compliant network port and said at least one non-SDN compliant network resource is a non-SDN compliant network port. A very wide variety of different network resources can thereby be controlled by the software defined networking controller. According to a fifth implementation form of the second aspect, the at least one SDN compliant network port and the at least non-SDN compliant network port are controlled to route incoming packets at these network ports to further network ports of said hybrid network component. A very flexible use of the network resources is thereby possible.

According to a sixth implementation form of the second aspect of the present invention, the at least one SDN compliant network port is an openflow-controlled port. By using the openflow standard, a very easy implementation can be achieved. According to a seventh implementation form of the second aspect, the SDN compliant network resources and non-SDN compliant network resources of the network components are controlled based on a data model including an abstract device entity for each network component. The abstract device entities each contain a number of abstract resource entities. The abstract resource entities each comprise abstract network ports or abstract network queues or abstract network flows. The resource entities each point to a specific implementation of a resource. The specific implementations of resources comprise network ports, network queues and network flows. By using such a data model, a very efficient implementation is possible.

According to an eighth implementation form of the second aspect, upon connection with a given network component, information from the given network component is received. The information regards the network resources available at the given network component. An abstract device entity for the given network component is created in the data model based upon the received information. Parts of the implementation can therefore be automated, further reducing the implementation effort.

According to a ninth implementation form, the hybrid network components are hybrid network switches or hybrid network routers comprising at least one SDN-compliant port and at least one non-SDN compliant port. Especially by use of hybrid network switches and hybrid network routers as hybrid network components, a large part of the overall hybrid network components are covered. For this large part of the available hybrid network components, the reduced implementation effort can be achieved. According to a tenth implementation form of the second aspect, a management controller controls the software defined networking controller by issuing route requests to the software defined networking controller. A high efficiency of implementation can thereby be reached. According to an eleventh implementation form, said route requests each comprise two of said network components, a data flow is to be initiated or terminated between. The managing controller therefore does not have to comprise detailed knowledge about the setup of the software defined network. This further increases efficiency. According to a twelfth implementation form of the second aspect of the present invention, the at least one SDN compliant network resource is an SDN compliant network port and the at least one non-SDN compliant network resource is a non-SDN compliant network port. The software defined networking controller initiates or terminates connections between said network ports of said at least one hybrid network component and network ports of said network components to initiate or terminate the data flow specified by the route request. A very efficient management of the software defined network is thereby achieved. According to a third aspect of the present invention, a computer program with program codes for performing the earlier-described method when the computer program runs on a computer, is provided.

Further advantageously, an attribute of each device level indicates which technology is associated with a specific device. The type of a resource (e.g. openflow type port vs. legacy type port) is derived from the device type. Therefore, there are no degrees of freedom in the resource level.

Advantageously, the type of a specific resource is a property of the resource allowing the device containing several resources each of a different technology (e.g. one openflow and the other legacy). Advantageously, the abstraction of devices within the SDN controller is done on the level of a sub-device, which corresponds to the resources of the device. As a result, the SDN controller is capable of dealing not only with devices porting multiple technologies in a mutually exclusive manner but actually using multiple technologies in tandem. Additionally, since SDN controllers provide a so-called "North-Bound Interface" for external applications to interact with the SDN controller, the present invention allows for more sophisticated applications - L2 and L3 types - to interact with the SDN controller. These and other aspects of the invention will be apparent from the embodiments described below.

Generally, it has to be noted that all arrangements, devices, elements, units and means and the forth described in the present invention could be implemented by software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionality described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if in the following description of the specific embodiments, a specific functionality or step to be performed by a general entity is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements or any kind combination thereof.

Moreover, it should be understood that features described as alternatives by using the term "OR" are not to be seen as mutually exclusive, but as combinable alternatives.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described in the following using the accompanying figures, in which

Fig. 1 shows a block diagram of a first embodiment of the invention;

Fig. 2 shows a block diagram of a more detailed second embodiment of the invention;

Fig. 3 shows an exemplary topology of a software defined network comprising hybrid switches;

Fig. 4 shows an exemplary routing table;

Fig. 5 shows exemplary software defined networking system;

Fig. 6 shows a more detailed view of an exemplary software defined networking system;

Fig. 7 shows an implementation of a first embodiment of the inventive software defined networking system;

Fig. 8 shows a representation of a data model used by a third embodiment of the inventive software defined networking controller; Fig. 9 shows a second view of the data model shown in Fig. 8;

Fig. 10 shows a third view of the data model shown in Fig. 8 and Fig. 9, and Fig. 11 shows a method for controlling a software defined network according to an embodiment of the present invention in a flow diagram.

DESCRIPTION OF EMBODIMENTS

First we demonstrate the construction and functionality of different embodiments of the software defined networking controller and software defined networking system along Fig. 1 - Fig. 4. Using Fig. 5 - Fig. 7, a software defined networking system according to an embodiment of the present invention is compared to conventional software defined networking systems. A data model which can be used by software defined networking controllers according to embodiments of the present invention is described along Fig. 8 - Fig. 10. Finally, a method for controlling a software defined network according to an embodiment of the present invention is described along Fig. 11. Similar entities and reference numbers in different Figures have been partially omitted to improve readability.

In Fig. 1, a software defined networking controller 2 according to an embodiment of the present invention is shown. The software defined networking controller 2 comprises a communication unit 3 (COM), which is connected with a control unit 4 (CTRL). In this example, the software defined networking controller 2 is shown as part of a software defined networking system 1, which furthermore comprises network components, out of which one network component 5 - a hybrid network component (HNC) - is depicted here. The hybrid network component 5 comprises a software defined networking compliant network resource 6 (SDN NR) and a non- software defined networking compliant network resource 7 (NON-SDN NR), which each are connected to the communication unit 3 of the software defined networking

controller 2. The communication unit 3 is connected to the control unit 4. The communication unit 3 serves the purpose of communicating with the network components 5 of the software defined networking system 1. The control unit is configured to control the at least one SDN compliant network resource 6 and the at least one non-SDN compliant network resource 7 of the hybrid network component 5.

In Fig. 2, a software defined networking controller 2 according to a further

embodiment of the present invention is shown. Also in this example, the software defined networking controller 2 is shown as part of a software defined networking system 1. Here, the software defined networking controller 2 additionally (when compared to Fig. 1) comprises a database 8 (DB), which is connected to the control unit 4. Moreover, in Fig. 2, an additional network component 10, which is a non-SDN compliant network component (NC), is depicted. The network component 10 comprises only non-SDN compliant network resources, out of which a non-SDN compliant network resource 11 is depicted here. The communication unit 3 is also connected to this non-SDN compliant network resource 11 of the additional network component 10. The control unit 4 is furthermore configured to also control the non- SDN compliant network resource 11 by use of the communication unit 3. Additionally, in Fig. 2, a management controller 9 (MAN CTRL) is depicted, which is connected to the communication unit 3.

In order to form a connection for transmitting data between two network

components 5, 10, the management controller 9 sends a route request to the software defined networking controller 2. In order to do so, the management controller 9 sends the route request to the communication unit 3 of the software defined networking controller 2, which forwards the route request to the control unit 4. The route request comprises identifications (e.g. ports, IP-addresses, MAC addresses or similar) of at least two network components between which a connection shall be established. As an example, identifications of the network components 5, 10 can be comprised in the route request, between which a connection is to be formed.

The software defined network controller 2 then initiates or terminates connections between said network ports of said at least one hybrid network component and network ports of said network components in order to initiate or terminate the data flow specified by the route request. In order to do so, the control unit 4 then determines, to which network resources packets have to be routed to establish a data flow between the respective network components 5, 10. In this case, the control unit 4 determines that packets have to be routed to the software defined networking compliant network resource 6 and to the non-software defined networking compliant network resource 11 in order to establish a data flow between the network component 5 and the network components 10.

In the examples depicted in Fig. 1 and Fig. 2, the network components 5, 10 are switches or routers. Especially, the hybrid network component 5 is for example a hybrid network switch or a hybrid network router, while the network component 10 is a non-SDN compliant network switch or network router. Although, in the described example, the SDN-compliant network resources and non-SDN compliant network resources are SDN compliant network ports and non-SDN compliant network ports. Alternatively, also queues or flows or other resource types can be employed.

When setting up the software defined networking system 1, the communication unit is configured to receive information regarding the network resources 6, 7, 11 of the hybrid network component 5 and advantageously any other network component 10 of the software defined networking system 1. This received information is stored in the databank 8. The network components are controlled based upon said stored information in the databank 8.

Especially, said information may indicate, whether a respective network resource of said hybrid network component is an SDN compliant network resource or a non-SDN compliant network resource. In case of the SDN compliant network resource 6 being an SDN compliant network port, advantageously, it is an openflow-controlled port.

When controlling the SDN compliant network resources and non-SDN compliant network resources, the software defined networking controller 2 performs this control based upon a data model including an abstract device entity for each network component 5, 10 controlled by the control unit 4. The abstract device entities each contain a number of abstract resource entities, the abstract resource entities comprising abstract network ports or abstract network queues or abstract network flows. The resource entity each point to a specific implementation of a resource, which comprise network ports, network queues and network flows. Regarding the data model, it is referred to the elaborations regarding Fig. 8 - Fig. 10.

Advantageously, the communication unit 3 furthermore receives information, when being connected to a specific network component regarding which network resources, the component comprises. In this case, the control unit 4 is configured to create an abstract device entity for the given network component in the data model based upon the received information. Especially, it is pointed out that in this document a software defined networking compliant network resource (such as the SDN compliant network resource 6) should be understood as a network resource, which is configurable using a software defined networking protocol, such as openflow. A non-SDN compliant network resource should be understood as a network resource which is configurable only using a legacy protocol, such as an Ethernet protocol. A non-SDN compliant network resource can also be designated as a legacy network resource.

In Fig. 3, a number of network components, especially network switches 30 - 36, which may be part of a software defined networking system 1 as shown in Fig. 1 and 2 is shown. The switches 30, 31, 33, 34 and 36 comprise only software defined networking compliant network ports A₁-A₄, B₁-B4, D₁-D4, E₁-E4, G₁-G4 as network resources. The switches 32 and 35 are hybrid network switches, since they comprise software defined networking compliant network ports Ci, C₂, Fi, F₂ and non-SDN compliant network ports C₃, C₄, F₃, F₄, which are labeled as legacy ports here.

Connections between individual ports of the switches 30-36 are depicted by lines and respective arrows. The arrows indicate the direction of traffic.

The connection of the respective ports of the switches is indicated in the routing table 40 of Fig. 4. The highlighted section of the routing table 40 indicates connections of non-SDN compliant network ports i.e. legacy ports in this example. It can be seen that a connection between non-SDN compliant network ports and SDN compliant network ports is also supported. In Fig. 5, an example of a software defined networking system is shown. The system shown here comprises a management controller 59, which is connected to a software defined networking controller 52, which again is connected to a number of network components 30-36 which correspond to the switches 30 - 36 of Fig. 3. Regarding the switches it is referred to the elaborations regarding Fig. 3.

The software defined networking controller 52 is for example implemented through the openflow protocol. The controller 52 enables intelligent traffic flow within the network of switches. The software defined networking controller 52 has access to the topology of the network of switches and is capable of configuring the traffic flow in the openflow components of the switches. Therefore, only traffic flow between openflow ports of the switches 30 - 36 can be controlled by the software defined networking controller 52. The management controller 59, which runs a management application, provides a management interface of switches via the software defined networking controller 52. Moreover, it provides a direct control of legacy ports of the switches. This aspect though is not depicted in Fig. 5. A use case relating to the setup shown in Fig. 5 comprises a route request for a path configuration in which the management application run by the management controller 59 defines only the end points of the path of the route request. The software defined networking controller 52 determines the path of individual packets between ports of the network components - the switches 30 - 36. The software defined networking controller 52 then configures software defined networking compliant network ports - openflow ports of the switches 30 - 36. Since these ports may not suffice for performing the entire path according to the route request, the management application run by the management controller 59 has to configure the non-SDN compliant network ports - i.e. the non-openflow ports in this example. This is depicted in greater detail in Fig. 6.

The setup in Fig. 6 corresponds to the setup in Fig. 5. In order to set up a new path, the management application run by the management controller 59 requests from the software defined networking controller 52 to set the port A₃ as a termination point and to set the port E₂ as a termination port. Therefore, the route request comprises the ports A3 and E₂. The controller receives the respective route request and determines which possible paths could connect these two destination ports. Two alternative paths are discovered:

1. A3 -»B2, B3-»Ci, C3-»D₂, D₃^G₃, G₂^F₄, F₂^E₂

2. A₃^B₂, B₄^F₃, F₂^E_2. The software defined networking controller 52 then decides for one of the possible paths. In this case, it decides for the shorter second path. The exemplary software defined networking controller 52 as depicted here is capable of configuring the ports A₃, B₂, B₄, F₂ and E₂, but is not capable of configuring the port F₃, since the switch 35, which comprises the port F₃ is a hybrid switch and the port F₃ is a non-SDN compliant network port - a legacy port. In order to set the path, the respective switches between A₃ and E₂ need to be configured. The software defined networking controller 52 configures the ports A₃, B₂, B₄, F₂ and E₂. The management application run by the management controller 59 configures the port F₃ via a legacy interface, for example SNMP.

Drawbacks of this setup are that the management controller 59 needs to have knowledge of the entire network setup and has to get involved in the configuring of ports. This results therein, that the management controller 59 cannot be a thin client, but requires processing power. Moreover, an external configuration manager is necessary, which supports legacy protocols. An additional deployment of such a configuration manager is therefore necessary. Although the logic for configuring ports is already implemented in the software defined networking controller 52, an additional very similar logic has to be implemented in the managing controller 59 for controlling the legacy ports.

In Fig. 7, a software defined networking system 71 according to an embodiment of the invention is shown. The software defined networking system 71 comprises a management controller 79, a software defined networking controller 72 according to an embodiment of the present invention and a network of switches 30 - 36, which correspond to network components. As described earlier, the switches 32, 35 are hybrid switches, while the remaining switches 30, 31, 33, 34 and 36 are software defined networking compliant network switches. The implementation of the embodiment of the present invention represents a straight forward approach of managing and controlling a software defined network, which corresponds to a mixture of openflow supporting switches and hybrid switches. The switches 30 - 36 used here can be the same switches as used in the example shown in Fig. 6. The main difference lays in the software defined networking controller 72 and the management controller 79. In order to form a path, the management controller sends a route request to the software defined networking controller 72. The route request indicates the ports A₃ and E₂ as termination points, defining ports which are to be connected by a data flow. The software defined networking controller 72 receives the route request and finds two alternative paths:

1. A₃^B₂, B₃^d, C₃^D₂, D₃^G₃, G₂^F₄, F₂^E₂

2. A₃^B₂, B₄^F₃, F₂^E_2. The software defined networking controller 72 then decides for one of the paths, in this case the shorter second path. After this, the software defined networking controller 72 configures the ports A₃, B₂, B₄, F₂, E₂ as well as F₃. All switch-related management commands regardless of their protocol are propagated from the software defined networking controller 72. There is no direct connection and communications channel between the management controller 79 and the individual network components - the switches 30 - 36 needed anymore. The entire management logic is removed from the management controller 79. The management controller 79 therefore can be a very low processing power system such as a thin client. Moreover, a more accurate management of hybrid switches is thereby possible. Also, an increase of consistency is reached. All management commands are processed in a single channel. There is no need for two different management channels. Moreover, a cost reduction can be achieved, since the option of deploying a separate configuration solution for legacy protocols is no longer necessary. Along Fig. 8 - Fig. 10, a data model 80 used for controlling the network resources is shown. Depicted here is an UML diagram depicting a data model supporting hybrid network components, such as the hybrid network component 5 of Fig. 1 and Fig. 2 and the hybrid network component 32, 35 of Fig. 3, and Fig. 5 - 7. The general concept behind this data model is an abstract device entity for each network component, for example for each switch or router. The abstract device entity 81 contains a number of abstract resource entities 83 - 86, which are concatenated by the block 82. The different types of RESOURCE objects, which correspond to the abstract resource entities, have some common features as well as unique attributes which can differ depending upon the technology used. The abstract resource entities 83 - 86 comprise abstract network ports 87 or abstract network queues 88 or abstract network flows 89. In this example, additionally an abstract resource element 86 containing non-defined abstract network resources 90 is shown for implementing future resources. The specific technology context is provided by a series of additional objects, which correspond to the abstract network ports 87 or abstract network queues 88 or abstract network flows 89.

Another legitimate object might be a LAYER2_PORT, which represents a legacy type resource. In this data model, the Network Element NE, which corresponds to the abstract device entity 81, remains abstract and may indirectly contain resources of various objects, such as OPENFLOW_PORT in tandem with L A YER2_PORT .

The abstract resource entities 83 - 86 each point to a specific implementation of a resource 87 - 90. The specific implementations of resources 87 - 90 comprise network ports, network queues and network flows indicated by the individual logs in the area labeled concrete resources.

Finally, in Fig. 11, a method for controlling a software defined network according to an embodiment of the present invention is shown. In a first step 100, a software defined network is provided comprising at least one hybrid network component, which comprises at least one SDN-compliant network resource and at least one non-SDN compliant network resource. In a second step 101, a management controller controls a software defined networking controller by sending a route request to the software defined networking controller. In a final step 102, the software defined networking controller controls the at least one SDN compliant network resource and the at least one non-SDN compliant network resource of the hybrid network component.

Regarding the further details of the method for controlling the software defined network, it is referred to the earlier elaborations regarding the software defined networking controller and software defined networking system.

Embodiments of the present invention are not limited to the examples and especially not to the openflow and Open Daylight standards. The concept discussed above can be applied to any software defined network system, comprising hybrid network components. The characteristics of the exemplary embodiments can be used in any advantageous combination.

The invention has been described in conjunction with various embodiments herein. However, other variations to the enclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word

"comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be

stored/distributed on a suitable medium, such as an optical storage medium or a solid- state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the internet or other wired or wireless telecommunication systems.

Claims

1. Software defined networking, SDN, controller (2, 72) comprising:

a communication unit (3) configured to communicate with network components (5, 10, 30 - 36), and

a control unit (4),

wherein the network components (5, 10, 30 - 36) comprise at least one hybrid network component (5, 32, 35) comprising at least one SDN compliant network resource (6, Ci, C₂, Fi, F₂), and at least one non-SDN compliant network resource (7, C₃, C₄, F₃, F₄), and

wherein the control unit (4) is configured to control the at least one SDN compliant network resource (6, Q, C₂, F_l5 F₂) and the at least one non-SDN compliant network resource (7, C₃, C₄, F₃, F₄).

2. Software defined networking controller (2, 72) according to claim 1,

wherein the communication unit (3) is configured to receive information regarding said network resources (6, 7, Ci, C₂, C₃, C₄, Fi, F₂, F₃, F₄) of said hybrid network component (5, 32, 35),

wherein the software defined network controller (2, 72) further comprises a databank (8) for storing said received information, and

wherein the control unit (4) is configured to control said network resources (6, 7, Ci, C₂, C₃, C₄, Fi, F₂, F₃, F₄) of said hybrid network component (5, 32, 35) based upon said stored information.

3. Software defined networking controller (2, 72) according to claim 2,

wherein said information indicates, whether a respective network resource (6, 7, Ci, C₂, C₃, C₄, Fi, F₂, F₃, F₄) of said hybrid network component (5, 32, 35) is an SDN compliant network resource (6, Q, C₂, F_l5 F₂) or a non-SDN compliant network resource (7, C₃, C₄, F₃, F₄).

4. Software defined networking controller (2, 72) according to any of the claims 1 to 3, wherein said at least one SDN compliant network resource (6, Ci, C₂, Fi, F₂) is a software defined networking queue or a software defined networking flow.

5. Software defined networking controller (2, 72) according to any of the claims 1 to 3, wherein said at least one SDN compliant network resource (Ci, C₂, Fi, F₂) is an SDN compliant network port (Ci, C₂, Fi, F₂), and

wherein said at least one non-SDN compliant network resource (C₃, C₄, F₃, F₄) is a non-SDN compliant network port (C₃, C₄, F₃, F₄).

6. Software defined networking controller (2, 72) according to claim 5,

wherein the control unit (4) is configured to control the at least one SDN compliant network port (Ci, C₂, Fi, F₂) and the at least one non-SDN compliant network port (C₃, C₄, F₃, F₄) to route incoming packets at these network ports (Ci, C₂, C₃, C₄, Fi, F₂, F₃, F₄) to further network ports (Ci, C₂, C₃, C₄, Fi, F₂, F₃, F₄) of said hybrid network component (5, 32, 35).

7. Software defined networking controller (2, 72) according to any of the claims 5 to 6, wherein the at least one SDN compliant network port (Ci, C₂, Fi, F₂) is an open flow- controlled port.

8. Software defined networking controller (2, 72) according to any of the claims 1 to 7, wherein the control unit (4) is configured to control the SDN compliant network resources (6, Q, C₂, F_l5 F₂) and non-SDN compliant network resources (7, C₃, C₄, F₃, F₄) of the network components (5, 10, 30 - 36) based on a data model (80) including an abstract device entity (81) for each network component (5, 10, 30 - 36) controlled by the control unit (4),

wherein the abstract device entities (81) each contain a number of abstract resource entities (83 - 86), the abstract resource entities (83 - 85) comprising abstract network ports (87) or abstract network queues (88) or abstract network flows (89),

wherein the abstract resource entities (83 - 85) each point to a specific implementation of a resource,

wherein the specific implementations of resources comprise network ports, network queues and network flows.

9. Software defined networking controller (2, 72) according to claim 8,

wherein the communication unit (3) is configured to, upon connection with a given network component (5, 10, 30 - 36), receive information from the given network component (5, 10, 30 - 35), the information regarding the network resources (6, 7, 11) available at the given network component (5, 10, 30 - 35); and

wherein the control unit (4) is configured to, based on the received information, create an abstract device entity (81) for the given network component (5, 10, 30 - 35) in the data model (80).

10. Software defined networking controller (2, 72) according to any of the claims 1 to 9,

wherein the hybrid network components (5, 32, 35) are hybrid network switches (5, 32, 35) or hybrid network routers comprising at least one SDN compliant network port (Ci, C₂, Fi, F₂) and at least one non-SDN compliant port (C₃, C₄, F₃, F₄).

11. Software defined networking system (1, 71) comprising a software defined networking controller (2, 72) according to any of the claims 1 to 10, a management controller (9), and at least two network components (5, 10, 30 - 36),

wherein the management controller (9) is configured to control the software defined networking controller (2, 72) by issuing route requests to the software defined networking controller (2, 72).

12. Software defined networking system (1, 71) according to claim 11,

wherein said route requests each comprise two of said network components (5, 10, 30 - 36), a data flow is to be initiated or terminated between.

13. Software defined networking system (1, 71) according to claim 12,

wherein the software defined networking controller (2, 72) is a software defined network controller (2, 72) according to any of the claims 5 to 10, and

wherein the software defined network controller (2, 72) is configured to initiate or terminate connections between said network ports (6, 7, CI, C2, C3, C4, Fl, F2, F3, F4) of said at least one hybrid network component (5, 32, 35) and network ports (11, A₁-A4, B₁-B4, D₁-D4, E₁-E4, G₁-G₄)) of said network components (11, 30, 31, 33, 34, 36) to initiate or terminate the data flow specified by the route request.

14. Method for controlling a software defined network using a software defined networking controller (2, 72), wherein the software defined network comprises the software defined networking controller (2, 72) and network components (5, 10, 30 - 36) comprising at least one hybrid network component (5, 32, 35),

wherein the at least one hybrid network component (5, 32, 35) comprises at least one SDN compliant network resource (6, Ci, C₂, Fi, F₂) and at least one non-SDN compliant network resource (7, C₃, C₄, F₃, F₄), and

wherein the software defined networking controller (2, 72) controls the at least one SDN compliant network resource (6, Q, C₂, F_l5 F₂) and the at least one non-SDN compliant network resource (7, C₃, C₄, F₃, F₄).

15. A computer program with a program code for performing the method according to claim 14 when the computer program runs on a computer.