CN108206783B

CN108206783B - Address configuration method and device in software defined network system

Info

Publication number: CN108206783B
Application number: CN201611164953.7A
Authority: CN
Inventors: 温海波
Original assignee: Nokia Shanghai Bell Co Ltd
Current assignee: Nokia Shanghai Bell Co Ltd
Priority date: 2016-12-16
Filing date: 2016-12-16
Publication date: 2020-11-06
Anticipated expiration: 2036-12-16
Also published as: WO2018109550A1; CN108206783A

Abstract

The invention provides a software-defined access network system and an address configuration method thereof, wherein one or more access nodes receive a routing request message from a user network, and encapsulate the routing request message into an OpenFlow message for forwarding; the software-defined network controller receives the OpenFlow message from the access node, identifies the routing request message in the OpenFlow message, allocates corresponding network prefixes, constructs a corresponding routing advertisement message, and encapsulates the routing advertisement message into an OpenFlow message to be sent to the access node; the access node is further configured to receive the route advertisement message from the software defined network controller and forward the route advertisement message to a user network. The invention can effectively combine the IPv6 technology and the software defined network technology to meet the address requirement of a future access network, realize the separation of control and forwarding, and quickly deploy various value-added services of the Internet of things.

Description

Address configuration method and device in software defined network system

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method, an apparatus, and a system for configuring an address in a software-defined networking system.

Background

Networks are currently taking a new era of the internet of things, with billions of embedded technology-based devices achieving seamless interconnection, being managed, and interacting securely with the network. The original address management scheme based on IPv4 has the advantage that at most 2 devices of power 32 can be connected to the Internet, and the future requirements can not be met. To expand the address space, the address space is to be redefined by IPv 6. IPv6 provides addresses almost limitlessly with a 128-bit address length.

On the other hand, the SDN (software defined network) network is a novel network innovation architecture, and is an implementation manner of network virtualization, and a core technology thereof separates a control plane and a data plane of network equipment, so that flexible control of network traffic is realized, and the network becomes more intelligent as a pipeline. The data plane is only responsible for simple data forwarding, the control plane adopts an integrated controller and is responsible for controlling different service logics and forwarding modes, an open programmable interface is provided between the control plane and the data plane, and the current mainstream protocol is the Openflow protocol.

For the IPv6 address management scheme, address automatic configuration is a very important technical implementation, and how to effectively implement IPv6 stateless address automatic configuration in future SDN network architectures is a problem which needs to be solved urgently.

Disclosure of Invention

To at least partially solve the above and other potential problems, embodiments of the present disclosure propose a stateless address configuration solution in a software defined networking system.

One embodiment of the present application provides a software-defined access network system, including: one or more access nodes, configured to receive a route request message from a user network, and encapsulate the route request message into an OpenFlow message for forwarding; the software-defined network controller is used for receiving the OpenFlow message from the access node, identifying the routing request message in the OpenFlow message, distributing corresponding network prefixes, constructing a corresponding routing advertisement message, packaging the routing advertisement message into an OpenFlow message and sending the OpenFlow message to the access node; wherein the access node is further configured to receive the route advertisement message from the software defined network controller for forwarding to a subscriber network.

In particular, when the access node encapsulates the route request message into an OpenFlow message, the access node further includes a user network identifier corresponding to the route request message.

Specifically, the OpenFlow message encapsulating the route request message by the access node is a Packet-In message.

Specifically, the software-defined network controller allocates a corresponding network prefix according to a user network identifier in the received OpenFlow message.

Specifically, the OpenFlow message of the network controller encapsulated by the software definition is a Packet-Out message.

One embodiment of the application provides a method for stateless address configuration of a software defined network, wherein one or more access nodes receive a routing request message from a user network, encapsulate the routing request message into an OpenFlow message, and forward the OpenFlow message to a software defined network controller of the access network; the software defined network controller receives the OpenFlow message, identifies the routing request message in the OpenFlow message, distributes corresponding network prefixes, constructs corresponding routing notification messages, packages the routing notification messages into OpenFlow messages and sends the OpenFlow messages to the access node; wherein the access node further receives the route advertisement message from the software defined network controller for forwarding to a subscriber network.

One embodiment of the application provides a method for assisting stateless address configuration on a software defined network in an access node, which receives a routing request message from a user network, encapsulates the routing request message into an OpenFlow message and sends the OpenFlow message to a software defined network controller; receiving OpenFl containing route advertisement messages from the software defined network controller_ow message, constructing route notice message and forwarding to user network.

In particular, when encapsulating the routing request message into an OpenFlow message, the access node further includes a user network identifier corresponding to the routing request message.

Specifically, the OpenFlow message of the access node encapsulating the route request message is a Packet-In message

An embodiment of the present application also provides an access node for performing any of the above methods.

An embodiment of the present application provides a method for stateless address configuration of an access network in a software-defined network controller, which receives OpenFlow messages from one or more access nodes in the access network, identifies routing request messages therein and assigns corresponding network prefixes, constructs corresponding routing advertisement messages, and encapsulates the routing advertisement messages into OpenFlow messages to be sent to the access nodes.

Specifically, the OpenFlow message of the network controller is encapsulated by the software defined network as a Packet-Out message.

An embodiment of the present application further provides a software-defined network controller implementing any one of the above methods.

By adopting the technical scheme of stateless address configuration provided by the embodiment of the application, the IPv6 technology and the SDN technology can be effectively combined to meet the requirements of a future access network (a large amount of addressing space and rapid service deployment), and the separation of control and forwarding and the rapid deployment of various new applications such as various value-added services of the Internet of things are realized.

Drawings

The present disclosure will be better understood and other objects, details, features and advantages thereof will become more apparent from the following description of specific embodiments of the present disclosure, which is given by reference to the following drawings. In the drawings:

fig. 1 shows a schematic diagram of a conventional access network system structure;

fig. 2 shows an address configuration flowchart under a conventional access network system;

figure 3 illustrates an SDN access network system architecture diagram according to one embodiment of the present disclosure;

figure 4 illustrates a stateless address auto-configuration flow diagram in an SDN access network system according to one embodiment of the disclosure;

fig. 5 illustrates an example IGMPv6 message format in accordance with the present disclosure; and

fig. 6 shows a Packet-In message of an embodiment of the present application.

Detailed Description

Example embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Fig. 1 shows a conventional access network system structure, in which network devices in a subscriber network can be directly or through various different ways, such as AN optical distribution network (0DN), xDSL, PON network, point-to-point optical fiber link, or WiFi wireless link, etc., and a broadband network gateway BNG in the access network system serves as a border router responsible for device address configuration management in the access network system, and the subscriber host has a global unicast address through a router request RS and a router advertisement RA message between the subscriber host and the broadband network gateway BNG.

Generally, the stateless address autoconfiguration process for one IPv6 includes two phases: configuration of link local addresses and configuration of global unicast addresses. When a network interface of a host device in a user network is enabled, the host device will first: : a/64 and EUI-64 interface identifier, a link local address is generated for the interface, and if an address conflict occurs in a subsequent duplicate address conflict check (DAD), the local link address must be manually configured for the interface, otherwise the interface will not be available. Referring to fig. 2, which illustrates an address configuration flowchart under a conventional access network system, the steps of configuring the global unicast address on the host device in the user network are as follows: firstly, after configuring a link local address, the host equipment sends a router request RS message to request prefix information of the router. And secondly, after receiving the router advertisement RS message, the BNG sends a unicast router advertisement RA message carrying prefix information for automatic configuration of the stateless address. And at the same time, BNG can periodically send multicast router advertisement RA message, and carry prefix information for automatic configuration of stateless address. And then, after receiving the router advertisement RA message, the host equipment generates a temporary global unicast address according to the prefix information and the configuration information. And simultaneously starting the DAD, sending an NS message to verify the uniqueness of the temporary address, wherein the address is in a temporary state, after other network nodes on the link in the user network receive the NS message of the DAD, if no user uses the address, discarding the message, otherwise, generating an NA message for responding to the NS. If the host device does not receive the NA message of the DAD and the address is indicated to be globally unique, the temporary address is used for initializing the interface, and the address enters an effective state at the moment.

As mentioned above, in the conventional access network system, the host in the user network and the BNG exchange router solicitation/router advertisement (RS/RA) message directly pass through the access node, and this address configuration mode has a certain disadvantage in the SDN access network architecture, because in the SDN network system, any data flow is prohibited from spreading to the network side unless the path is allowed by configuration; although it is possible to allow a host and a BNG in a subscriber network to exchange RS/RA messages by establishing a specific channel between the BNG and an access node device in advance, this would lead to potential network attacks and degrade the programmable performance of the SDN network.

Fig. 3 shows a schematic diagram of an SDN access network system structure according to an embodiment of the present disclosure, in which a network device in a user network can access an

access node

321, 322 directly or through various different ways, for example, an Optical Distribution Network (ODN), xDSL, PON network, point-to-point optical fiber link, or WiFi wireless link. The

access nodes

321, 322 operate under the control of the SDN controller 301 in the access network, which may also include one or

more switches

341 and 343. In addition, the access network may further include a broadband network gateway BNG305, each operable under the control of the SDN controller 301. According to an embodiment of the present application, the

access node

321 and 322, the

intermediate switch

341 and 343, and the broadband network gateway 305 may all operate under the control of the SDN controller 301 of the access network through an OpenFlow protocol. The SDN controller 301 configures the forwarding rules of the foregoing network devices, and only allowed data flows that meet the requirements of the configuration conditions can be forwarded in the access network system.

According to an embodiment of the application, both

access nodes

321, 322 are only data plane enabled, where the

access nodes

321, 322 are provided with a proxy device that is not control plane enabled and that is not capable of handling control related messages from the host device in the user network 330. For example: upon receiving the router request RS message from the user network 330, which relates to the IPv6 stateless address configuration, the access node 321 encapsulates the RS message and the user network identifier R-ID corresponding to the user network 330 into an OpenFlow message, and sends the OpenFlow message to the SDN controller 301. Meanwhile, the access node 321 receives the OpenFlow message including the RA message from the SDN controller 301, parses the corresponding router advertisement RA message and the user network identifier R-ID, and sends the router advertisement RA message to the corresponding user network 330.

The aforementioned subscriber network identification R _ ID may be information uniquely identifying the subscriber network, such as: the port number of the access node connecting the user network, or the combination of the access node and the port number, or a unique number calculated by some coding mode.

According to an embodiment of the present application, the OpenFlow message including the router advertisement RA message may be encapsulated into a Packet-In message, and when the

access nodes

321 and 322 receive a data Packet and do not match with the flow entry In the access node successfully, the switch encapsulates the data In the Packet-In message and sends the Packet-In message to the controller for processing. At which time the packet may be buffered in the switch awaiting processing. FIG. 6 illustrates a Packet-In message of one embodiment of the present application; wherein, the part represented by 601 is to adjust the Reason part of the Packet-In message, we define a new Reason type value, which is directly used to indicate the IPv6 Packet requested by the router whose Match domain (payload domain) is, and does not contain other domains of the ethernet frame at this time; the struct of p-match portion represented by 602 is a router solicitation message encapsulated In a Packet-In message; in addition, the part represented by 601 may not specifically indicate a Reason type value, and an ethernet frame containing a router request RS message is directly placed in a Match payload area, and sent to an SDN controller to analyze the payload area to determine whether the router request RS message is the router request RS message.

According to an embodiment of the present application, the aforementioned RS message including the router request may also be encapsulated in other types of flow messages, the SDN controller needs to perform specific configuration on a flow entry of the access node in advance, and when the access node receives the RS message including the router request from the user network, the SDN controller adapts filtering according to the flow entry, encapsulates the RS message including the router request into a specific flow control message, and sends the flow control message to a specified network device, which may be the SDN controller 301 or the BNG 305.

According to an embodiment of the present application, SDN controller 301 aggregates control plane functions of the access network, where SDN controller 301 sets a stateless address autoconfiguration SAAC device that maintains an IPv6 prefix information table in which IPv6 prefixes assigned to each user network are recorded. Each entry of the IPv6 prefix information table has a format of < user network identification R-ID, IPv6 prefix information >, and thus, each user network can be identified by the user network identification R _ ID in the prefix information table. When a stateless address auto-configuration SAAC device receives a router request RS message from a certain access node, the message is sealed In a certain specific message of OpenFlow, such as a Packet-In message, the IPv6 prefix information corresponding to the user network is obtained based on a user network identifier R-ID and a search IPv6 prefix information table In the RS message, and a related router advertisement RA message is constructed and packaged In a certain specific message of OpenFlow, for example, a Packet-Out message is sent to a corresponding access node.

For each authorized user network, SDN controller 301 may periodically send an RA message encapsulated in an OpenFlow message to its corresponding access node, which also includes an authorized user network identification R _ ID.

According to an embodiment of the present application, the

access nodes

321 and 322 receive the OpenFlow message from the SDN controller 301, and if a router advertisement RA message carried in the OpenFlow message is received, it obtains a user network identifier R _ ID and IPv6 prefix information of a user network therein, and constructs a corresponding router advertisement RA message to advertise a network prefix of a host device in the user network.

And then, after the host equipment in the user network receives the router advertisement RA message, a temporary global unicast address is generated according to the prefix information and the configuration information. And simultaneously starting the DAD, sending an NS message to verify the uniqueness of the temporary address, wherein the address is in a temporary state, after other network nodes on the link in the user network receive the NS message of the DAD, if no user uses the address, discarding the message, otherwise, generating an NA message for responding to the NS. If the host device does not receive the NA message of the DAD and the address is indicated to be globally unique, the temporary address is used for initializing the interface, and the address enters an effective state at the moment.

Fig. 4 is a flow chart illustrating stateless address autoconfiguration in a software defined access network.

Step S401, the host device in the user network sends a router solicitation RS message to the access node, for example, 221, and in combination with the message format of IGMPv6 (sixth version internet group management protocol) illustrated in fig. 5, the ICMPv6 packet has a next radical field with a value of 58, and the IPv6 destination address is FF 02: : and 2, the type field is 133, and the message body specifically represents the router solicitation message.

At step S402, the access node 321 identifies the router solicitation RS message it receives. The access node 321 may make this identification based on different clues, and as previously described, the router solicitation RS message may be quickly identified by identifying the next radical field in the ICMPv6 message, the IPv6 destination address, and the type field. Of course, one of ordinary skill in the art will recognize that different recognition rules may be set as desired without departing from the scope of the present application.

In step S403, the access node 321 further encapsulates the router solicitation RS message into a message type compatible with the OpenFlow standard of the SDN, and encapsulates the user network identifier R-ID of the host device into the message together, and sends the message to the SDN controller 301. Typically, the OpenFlow message type may be a Packet-In message, and of course, other OpenFlow message types may be defined according to different application scenarios.

In step S404, the SDN controller 301 decapsulates the received OpenFlow message. Since the Packet-In message provided by the present application includes a router solicitation RS message and a user network identifier R-ID, the controller 101 may directly use a corresponding control module to process the router solicitation RS message, and In combination with a Pv6 prefix information table In the SDN controller 301, an IPv6 prefix assigned to each user network is recorded In the table. Each table entry of the IPv6 prefix information table has a format of < user network identifier R _ ID, IPv6 prefix information > and based on the user network identifier R-ID in the received message, the IPv6 prefix information table is searched, i.e., the IPv6 prefix information corresponding to the user network is obtained.

Preferably, the SDN controller 301 may perform prefix allocation through a certain set policy, for example, a user belonging to a certain area is allocated a certain prefix, or the user belongs to a certain type of user is allocated a certain prefix.

Step S405, the SDN controller 301 constructs a relevant RA message and encapsulates the RA message in a certain specific message of OpenFlow, for example, a Packet-Out message, and sends the RA message to a corresponding access node 321, where the router advertisement RA message includes IPv6 prefix information corresponding to the user network.

For each authorized user network, the SDN controller 301 may encapsulate the multicast router advertisement RA message in a specific message of OpenFlow, and periodically send the message to an access node corresponding to each authorized user network.

In step S406, the access node 321 decapsulates the received OpenFlow message to obtain an RA message.

Step S407, the access node 321 constructs a corresponding router request RS message to send to the host device in the user network, and combines the IGMPv6 message format illustrated in fig. 5, where the ICMPv6 packet has a next radical field with a value of 58, and the IPv6 target address is FF 02: : 1, the type field is 134, wherein the message body has an optional TLV (type, length, value) field, and when the type is 3, the corresponding value field is IPv6 prefix information.

And then, after the host equipment in the user network receives the router advertisement RA message, a temporary global unicast address is generated according to the prefix information and the configuration information.

In one or more exemplary designs, the functions of this application may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. Such computer-readable media can comprise, for example, but is not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code means in the form of instructions or data structures and which can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A software defined access network system comprising:

one or more access nodes, configured to receive a routing request message from a user network, and encapsulate the routing request message into an OpenFlow message for forwarding;

the software-defined network controller is used for receiving the OpenFlow message from the access node, identifying the routing request message in the OpenFlow message, distributing corresponding network prefixes, constructing a corresponding routing advertisement message, packaging the routing advertisement message into an OpenFlow message and sending the OpenFlow message to the access node;

wherein the access node is further configured to receive the route advertisement message from the software defined network controller for forwarding to a subscriber network,

when the access node encapsulates the routing request message into an OpenFlow message, the access node further includes a user network identifier corresponding to the routing request message, so that the software-defined network controller can allocate a corresponding network prefix based on the user network identifier.

2. The access network system of claim 1, wherein the OpenFlow message encapsulating the route request message is a Packet-In message.

3. The access network system of claim 1, wherein the OpenFlow message encapsulating the route advertisement message by the software defined network controller is a Packet-Out message.

4. A method for stateless address configuration for a software defined network, comprising:

receiving a routing request message from a user network by one or more access nodes, packaging the routing request message into an OpenFlow message, and forwarding the OpenFlow message to a software-defined network controller of the access network;

the software defined network controller receives the OpenFlow message, identifies the routing request message in the OpenFlow message, distributes corresponding network prefixes, constructs corresponding routing notification messages, packages the routing notification messages into OpenFlow messages and sends the OpenFlow messages to the access node;

wherein the access node further receives the route advertisement message from the software defined network controller to forward to a subscriber network,

wherein the access node further includes a user network identifier corresponding to the routing request message when encapsulating the routing request message into an OpenFlow message,

and the software-defined network controller allocates corresponding network prefixes according to the user network identifiers in the received OpenFlow messages.

5. The method of claim 4, wherein the OpenFlow message In which the access node encapsulates the route request message is a Packet-In message.

6. The method of claim 4, wherein the OpenFlow message that the software defined network controller encapsulates a route advertisement message is a Packet-Out message.

7. A method for facilitating stateless address configuration for a software defined network in an access node, comprising:

receiving a routing request message from a user network, packaging the routing request message into an OpenFlow message, and sending the OpenFlow message to a software defined network controller;

receiving an OpenFlow message containing a route advertisement message from the software defined network controller, constructing a route advertisement message to forward to a user network,

8. The method of claim 7, wherein the OpenFlow message encapsulating the route request message is a Packet-In message.

9. An access node for performing the method of any of claims 7-8.

10. A method for stateless address configuration of an access network in a software defined network controller, comprising:

receiving an OpenFlow message from one or more access nodes in the access network;

identifying the routing request message and distributing corresponding network prefix;

constructing a corresponding route advertisement message and encapsulating the route advertisement message into an OpenFlow message to be sent to the access node,

11. The method of claim 10, wherein the software defined network controller assigns a corresponding network prefix according to a user network identification in the received OpenFlow message.

12. The method of claim 10, wherein the OpenFlow message encapsulating the route advertisement message by the software defined network controller is a Packet-Out message.

13. A software defined network controller for performing the method of any one of claims 10 to 12.