FIELD OF THE INVENTION

This application relates to Open Shortest Path First (OSPF) protocol and in particular, to network system and method for supporting large number of OSPF process.

BACKGROUND

Open Shortest Path First (OSPF) is a link-state routing protocol designed to be used as an Interior Gateway Protocol (IGP). This means that it distributes routing information between routers belonging to a single Autonomous System (AS). The OSPF protocol is based on link-state or SPF Shortest Path First technology.

OSPF also can be used as IGP between Provider edge router (PE) and Customer edge router (CE) as part of Virtual Private Network (VPN) solution, where there would be a need to support a large number of VPN Routing & Forwarding (VRF) with a single PE router.

A PE router that attaches to more than one OSPF domain must run an independent instance of OSPF for each domain. If the PE is running OSPF as its IGP, the instance of OSPF running as the IGP must be separate and independent from any other instance of OSPF that the PE is running. Each interface that attaches to a VPN site belongs to no more than one OSPF instance.

VPN defines the notion of a Per-Site Routing and Forwarding Table, or VRF. Each VRF is associated with a set of interfaces. If a VRF is associated with a particular interface, and that interface belongs to a particular OSPF instance, then that OSPF instance is said to be associated with the VRF. If two interfaces belong to the same OSPF instance, then both interfaces must be associated with the same VRF. If an interface attaches a PE to a CE, and that interface is associated with a VRF, we will speak of the CE as being associated with the VRF.

However, the applicant found that the above implementation leads to scalability issues where OSPF running on a single processing unit to support large number of process.

OSPF in PE router within the single control board will not be able to support large number of OSPF process (which can be part of same VRF or different VRFs), which will cause the scalability issue in the network.

Reference 1 - "OSPF Version 2", RFC 2328.

Reference 2 -"OSPF as the Provider/Customer Wdge Protocol for BGP/MPLS IP Virtual Private Networks ", RFC 4577.

SUMMARY
Embodiments of the present invention pertain to a network system and method of communicating for supporting large number of process. The aim is to support large number of process without scalability and performance issues in PE-CE scenario.

According a first aspect of the embodiments of the present invention, there is provided a network system for supporting large number of OSPF process, the network system includes:

One or more line cards, configured to receive a packet from outside and to dispatch the packet to corresponding OSPF process based on a session table;

Two or more control boards, configured to receive the packet dispatched by the line card and to perform OSPF handling; wherein large number of OSPF process is distributed across the two or more control boards.

According a second aspect of the embodiments of the present invention, there is provided a method for supporting large number of OSPF process, the method includes:

Receiving, by one of line cards, a packet from outside and dispatching the packet to corresponding OSPFprocess based on a session table;

Receiving, by one of control boards, the packet dispatched by the line card and performing OSPF handling; wherein large number of OSPF process is distributed across the multiple control boards.

The advantages of the present invention exist in that large number of OSPF process can be supported such that scalability and performance can be improved in PE-CE scenario.

These and further aspects and features of the present invention will be apparent with reference to the following description and attached drawings. In the description and drawings, particular embodiments of the invention have been disclosed in detail as being indicative of some of the ways in which the principles of the invention may be employed, but it is understood that the invention is not limited correspondingly in scope. Rather, the invention includes all changes, modifications and equivalents coming within the spirit and terms of the appended claims.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. To facilitate illustrating and describing some parts of the invention, corresponding portions of the drawings may be exaggerated in size, e.g., made larger in relation to other parts than in an exemplary device actually made according to the invention. Elements and features depicted in one drawing or embodiment of the invention may be combined with elements and features depicted in one or more additional drawings or embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views and may be used to designate like or similar parts in more than one embodiment.

BRIEF DESCRIPTION OF THE DRAWING

The drawings are included to provide further understanding of the present invention, which constitute a part of the specification and illustrate the preferred embodiments of the present invention, and are used for setting forth the principles of the present invention together with the description. The same element is represented with the same reference number throughout the drawings.
In the drawings:

Figure 1 is a topology diagram showing a typical example of OSPF process;

Figure 2 is a topology diagram showing a typical example of OSPF between PE and CE to support large number of VRF;

Figure 3 is a schematic diagram of the network system of an embodiment of the present invention;

Figure 4 is a schematic diagram of the network system of another embodiment of the present invention;
Figure 5 is a schematic diagram of the handling routes;

Figure 6 is a schematic diagram of the SMP command processing;

Figure 7 is flowchart of the method of an embodiment of the present invention;

Figure 8 is flowchart of the method of another embodiment of the present invention;

Figure 9 is flowchart of the method of another embodiment of the present invention.

DETAILED DESCRIPTION

The many features and advantages of the embodiments are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the embodiments that fall within the true spirit and scope thereof. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the inventive embodiments to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope thereof.

The preferred embodiments of the present invention are described as follows in reference to the drawings.

Nowadays, OSPF process will run in a single control plane. Figure 1 is a topology diagram showing a typical example of OSPF process. Current typical deployment of OSPF within the single control plane has been shown as Figure 1.

As shown in Figure 1, there are a control board and a line card, and OSPF process is running in the control board. When OSPF is deployed to support large number of process, it will have the following issues: processing of large number of packet, congestion between the control board and the line card, processing power, memory, and so on.

Figure 2 is a topology diagram showing a typical example of OSPF between PE and CE to support large number of VRF. In this topology, OSPF is used between PE and CE.

As shown in Figure 2, there will many number of CE connected to single PE OSPF running in PE (in single control plane) will have problem to support large number of VRF requirements.

Furthermore, there are LSA updates in multiple OSPF process. For example, OSPF needs to process large number of LSA coming from many CE's, and single control plane will not be able to process because of this under socket layer will get congested.

Furthermore, once the socket layer starts buffering the packet, it will cause the congestion between control plane and line card. This will cause more delay in the packet processing in OSPF, furthermore it will cause to miss the ACK from neighbors. It will make the retransmission-queue maintained in the OSPF to grow. Then whole OSPF will slow down because of this and will impact overall convergence of the network.

Embodiment 1

This embodiment of the present invention provides a network system for supporting large number of OSPF process. Figure 3 is a schematic diagram of the network system of an embodiment of the present invention.

As shown in Figure 3, the network system 300 comprising: one or more line cards 301 and two or more control boards 302; wherein the line card 301 is used to receive a packet from outside and to dispatch the packet to corresponding OSPF process based on a session table; the control board 302 is used to receive the packet dispatched by the line card 301 and to perform OSPF handling.

In this embodiment, in the carrier class router, it will have multiple control boards, and large number of OSPF process is distributed across the multiple control boards.

On PE router, distributed OSPF will be across multiple control planes (control boards) based on the number of OSPF process. Large number of OSPF process can be supported such that scalability and performance can be improved in PE-CE scenario.

Figure 4 is a schematic diagram of the network system of another embodiment of the present invention. As shown in Figure 4, the network system 400 includes: one or more line cards 401 and two or more control boards 402.

In this embodiment, as an example, there are three line cards and three control boards, and the number of OSPF process is 0-12K (0-4K, 4-8K, 8-12K).

As shown in Figure 4, the network system may further include: a central route manager (RM) 403, the central route manager 403 is used to receive updated route information and to redistribute the route information to all control boards; wherein the route information is calculated and sent independently by the control board 402.

In this embodiment, as shown in Figure 4, the RM 403 is inside of control board, but it is not limited thereof, the RM 403 may be outside of the control board (such as in MB-3).

As shown in Figure 4, a session table with a relationship of socket and interface is stored in each line card 401; and the line card 401 dispatches the packet to a corresponding socket by looking at the session table, so that the packet reach a corresponding control board by the corresponding socket.

In this embodiment, based on the capability of the control board and the number of process support required, OSPF should be distributed across multiple control board.

Furthermore, the line card will maintain its 'Session Table' with "Socket-interface" relation. When OSPF is enabled on the interface, socket will be created per interface. This Socket-Interface mapping will be updated to all line cards. The line card should send the incoming packet to respective control board.

Specifically, the line card may further include: socket creating unit, relationship updating unit and information sending unit. Wherein the socket creating unit is used to create socket per interface when OSPF is enabled on the interface; the relationship updating unit is used to update the relationship of socket and interface to all line cards; the information sending unit is used to send the packet to a corresponding control board.

In an embodiment of the present invention, the packet flow may be changed. For example, as for a coming packet from peer, the line card will receive the packet from outside. By looking ar the session table, the line card dispatches the packet to a corresponding socket, and the packet will reach a corresponding OSPF from the socket.

Furthermore, processing of the outgoing packet will be normal processing as it was for single control plane. Each control board will send the packets (LSA) to peers and acts independently with other control board to each other while send the packets out of it.

In another embodiment of the present invention, handling routes may be changed. Figure 5 is a schematic diagram of the handling routes, as shown in Figure 5, Each OSPF process in control board will calculate the route independently and updates to RM.

Furthermore, RM will redistribute the routes to all the OSPF process (as if all are RPAs). Each OSPF process should notify to RM for its existence earlier.

In another embodiment of the present invention, system management plane (SMP) command processing may be changed. OSPF command processing needed to be changed for address multiple Process across different Control Plane.

In this embodiment, the network system may further include a system management plane (SMP). The SMP is used to send a SMP command; wherein the SMP command is dispatched to all control boards if the SMP command is a global SMP command, and the SMP command is dispatched to a corresponding control board if the SMP command is a process specific SMP command.

Furthermore, the control board is further used to create a new OSPF process based on the load if the existing OSPF process is not able to handle.

Figure 6 is a schematic diagram of the SMP command processing, as shown in Figure 6, SMP module needs to the relationship of the OSPF process and the control board. All the global commands will be dispatched to all OSPF. And process specific command will be dispatched to respective OSPF,

In this embodiment, when user configures the new process, a new OSPF will be created based on the load if the existing OSPF is not able to handle.

It can be seen from the above embodiments that this invention provides network system to support large number of OSPF process by distributing of OSPF process across different control plane. Large number of OSPF process can be supported such that scalability and performance can be improved in PE-CE scenario.

Embodiment 2

The embodiments of the present invention further provide a method for supporting large number of OSPF process. This embodiment corresponds to the deviced in the above embodiment and the same content will not be described.

Figure 7 is flowchart of the method of an embodiment of the present invention. As shown in Figure 7, the method includes:

Step 701, line card receives a packet from outside and dispatches the packet to corresponding OSPF process based on session table;

Step 702, control board receives the packet dispatched by the line card and performs OSPF handling; wherein large number of OSPF process is distributed across multiple control boards.

In this embodiment, distributed OSPF will be across multiple control planes based on the number of OSPF process. Large number of OSPF process can be supported such that scalability and performance can be improved in PE-CE scenario.

In an embodiment of the present invention, the packet flow may be changed. Figure 8 is flowchart of the method of another embodiment of the present invention. As shown in Figure 8, the method includes:

Step 801, line card receives a packet from outside and dispatches the packet to corresponding OSPF process based on session table;

Step 802, control board receives the packet dispatched by the line card and performs OSPF handling; wherein large number of OSPF process is distributed across multiple control boards.

As shown in Figure 8, the method may further include:

Step 803, central route manager receives updated route information and redistributes the route information to all control boards; wherein the route information is calculated and sent by the control board independently.

In this embodiment, a session table with a relationship of socket and interface is stored in each line card; and the line card dispatches the packet to a corresponding socket by looking at the session table, so that the packet reach a corresponding control board by the corresponding socket.

In this embodiment, the step 802 may further include: create socket per interface when OSPF is enabled on the interface; update the relationship of socket and interface to all line cards; and send the packet to a corresponding control board.

In another embodiment of the present invention, handling routes may be changed. Each OSPF process in control board will calculate the route independently and updates to RM. RM will redistribute the routes to all the OSPF process (as if all are RPAs). Each OSPF process should notify to RM for its existence earlier.

In another embodiment of the present invention, SMP command processing may be changed. OSPF command processing needed to be changed for address multiple Process across different Control Plane.

Figure 9 is flowchart of the method of another embodiment of the present invention. As shown in Figure 9, the method includes:

Step 901, line card receives a packet from outside and dispatches the packet to corresponding OSPF process based on session table;

Step 902, control board receives the packet dispatched by the line card and performs OSPF handling; wherein large number of OSPF process is distributed across multiple control boards.
As shown in Figure 9, the method may further include:

Step 903, SMP module sends a SMP command; wherein the SMP command is dispatched to all control boards if the SMP command is a global SMP command, and the SMP command is dispatched to a corresponding control board if the SMP command is a process specific SMP command.

As shown in Figure 9, the method may further include:

Step 904, control board create a new OSPF process based on the load if the existing OSPF process is not able to handle.

It can be seen from the above embodiments that this invention provides network system to support large number of OSPF process by distributing of OSPF process across different control plane. Large number of OSPF process can be supported such that scalability and performance can be improved in PE-CE scenario.

The embodiments of the present invention further provide a computer- readable program, wherein when the program is executed in a network system; the program enables the computer to carry out the method of communicating for supporting large bumber of OSPF process.

The embodiments of the present invention further provide a storage medium in which a computer-readable program is stored, wherein the computer-readable program enables the computer to carry out the method of communicating for supporting large bumber of OSPF process.

It should be understood that each of the parts of the present invention may be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods may be realized by software or firmware that is stored in the memory and executed by an appropriate instruction executing system. For example, if it is realized by hardware, it may be realized by any one of the following technologies known in the art or a combination thereof as in another embodiment: a discrete logic circuit having a logic gate circuit for realizing logic functions of data signals, application-specific integrated circuit having an appropriate combined logic gate circuit, a programmable gate array (PGA), and a field programmable gate array (FPGA), etc.

The description or blocks in the flowcharts or of any process or method in other manners may be understood as being indicative of comprising one or more modules, segments or parts for realizing the codes of executable instructions of the steps in specific logic functions or processes, and that the scope of the preferred embodiments of the present invention comprise other implementations, wherein the functions may be executed in manners different from those shown or discussed, including executing the functions according to the related functions in a substantially simultaneous manner or in a reverse order, which should be understood by those skilled in the art to which the present invention pertains.

The logic and/or steps shown in the flowcharts or described in other manners here may be, for example, understood as a sequencing list of executable instructions for realizing logic functions, which may be implemented in any computer readable medium, for use by an instruction executing system, device or apparatus (such as a system including a computer, a system including a processor, or other systems capable of extracting instructions from an instruction executing system, device or apparatus and executing the instructions), or for use in combination with the instruction executing system, device or apparatus.

The above literal description and drawings show various features of the present invention. It should be understood that those skilled in the art may prepare appropriate computer codes to carry out each of the steps and processes as described above and shown in the drawings. It should be also understood that all the terminals, computers, servers, and networks may be any type, and the computer codes may be prepared according to the disclosure to carry out the present invention by using the apparatus.

Particular embodiments of the present invention have been disclosed herein. Those skilled in the art will readily recognize that the present invention is applicable in other environments. In practice, there exist many embodiments and implementations. The appended claims are by no means intended to limit the scope of the present invention to the above particular embodiments. Furthermore, any reference to "a device to..." is an explanation of device plus function for describing elements and claims, and it is not desired that any element using no reference to "a device to..." is understood as an element of device plus function, even though the wording of "device" is included in that claim.

Although a particular preferred embodiment or embodiments have been shown and the present invention has been described, it is obvious that equivalent modifications and variants are conceivable to those skilled in the art in reading and understanding the description and drawings. Especially for various functions executed by the above elements (portions, assemblies, apparatus, and compositions, etc.), except otherwise specified, it is desirable that the terms (including the reference to "device") describing these elements correspond to any element executing particular functions of these elements (i.e. functional equivalents), even though the element is different from that executing the function of an exemplary embodiment or embodiments illustrated in the present invention with respect to structure. Furthermore, although the a particular feature of the present invention is described with respect to only one or more of the illustrated embodiments, such a feature may be combined with one or more other features of other embodiments as desired and in consideration of advantageous aspects of any given or particular application.

WE CLAIM:

1) A network system for supporting large number of OSPF (Open Shortest Path First) process, the network system comprising:

one or more line cards, configured to receive a packet from outside and to dispatch the packet to corresponding OSPF process based on a session table;

two or more control boards, configured to receive the packet dispatched by the line card and to perform OSPF handling; wherein large number of OSPF process is distributed across the two or more control boards.

2) The network system according to claim 1, wherein the network system further comprising:

a central route manager, configured to receive updated route information and to redistribute the route information to all control boards; wherein the route information is calculated and sent by the control board independently.

3) The network system according to claim 1, wherein the session table with a relationship of socket and interface is stored in each line card;

and the line card dispatches the packet to a corresponding socket by looking at the session table, so that the packet reach a corresponding control board by the corresponding socket.

4) The network system according to claim 1, wherein the line card further comprising:

a socket creating unit, configured to create socket per interface when OSPF is enabled on the interface;

a relationship updating unit, configured to update the relationship of socket and interface to all line cards;

an information sending unit, configured to send the packet to a corresponding control board.

5) The network system according to claim 1, wherein the network system further comprising:

a system management plane, configured to send a system management plane (SMP) command; wherein the SMP command is dispatched to all control boards if the SMP command is a global SMP command, and the SMP command is dispatched to a corresponding control board if the SMP command is a process specific SMP command.

6) The network system according to claim 5, wherein the control board is further used to create a new OSPF process based on the load if the existing OSPF process is not able to handle.

7) A method for supporting large number of OSPF (Open Shortest Path First) process, the method comprising:

receiving, by one of line cards, a packet from outside and dispatching the packet to corresponding OSPF process based on a session table;

receiving, by one of control boards, the packet dispatched by the line card and performing OSPF handling; wherein large number of OSPF process is distributed across the multiple control boards.

8) The method according to claim 7, wherein the method further comprising:

receiving, by a central route manager, updated route information and redistributing the route information to all control boards; wherein the route information is calculated and sent by the control board independently.

9) The method according to claim 7, wherein the session table with a relationship of socket and interface is stored in each line card;

and the line card dispatches the packet to a corresponding socket by looking at the session table, so that the packet reaches a corresponding control board by the corresponding socket.

10) The method according to claim 7, wherein dispatching the packet based on the number of OSPF process further comprising:

creating socket per interface when OSPF is enabled on the interface; updating the relationship of socket and interface to all line cards; sending the packet to a corresponding control board.

11) The method according to claim 7, wherein the method further comprising:

sending, by a system management plane, a system management plane (SMP) command;

wherein the SMP command is dispatched to all control boards if the SMP command is a global SMP command, and the SMP command is dispatched to a corresponding control board if the SMP command is a process specific SMP command.

12) The method according to claim 11, wherein the method further comprising:

creating a new OSPF process based on the load if the existing OSPF process is not able to handle.