WO2009065343A1

WO2009065343A1 - Method, system and equipment for confirming edge devices

Info

Publication number: WO2009065343A1
Application number: PCT/CN2008/072963
Authority: WO
Inventors: Daoyan Yang
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-11-09
Filing date: 2008-11-05
Publication date: 2009-05-28
Also published as: CN101431465A

Abstract

A method for confirming edge devices includes: the first edge device of the transport network domain acquires the correspondence relationship of the second edge device and the address information from the control network element, wherein the correspondence relationship of the second edge device and the address information includes: the correspondence relationship of the second edge device and the address information of the out-domain network which the second edge device can reach, and/or, the correspondence relationship of the second edge device and the out-domain address information through the service flow of the second edge device; while the first edge device processes the service flow, the first edge device confirms the second edge device according to the address information in the service flow processed and the correspondence relationship. A transport network system, an edge device and a control network element. The present invention can confirm expediently the exit/entry edge device of the service flow.

Description

Method, system and device for determining edge device This application claims priority to Chinese Patent Application No. 200710169587.9, filed on November 9, 2007, entitled "Method, System and Device for Determining Edge Device" The entire contents of which are incorporated herein by reference. Technical field

Embodiments of the present invention relate to the field of communications, and in particular, to a method, system, and apparatus for determining an edge device. Background technique

In a communication transport network, it is often necessary to determine the ingress edge device of a given traffic flow at the egress edge device or to determine the egress edge device for a given traffic flow at the ingress edge device, as shown in Figure 1-a. In the transmission network domain of the congestion notification (PCN, Pre-Congestion Notification), A, B, and C are edge devices, and D is an internal node. When internal node D discovers that the traffic on a link exceeds the pre-congestion gate. When the time limit is specified, the packet is marked with a pre-cuffing flag of the PCN. When the host (Host) 1 is the source address and the host 2 is the destination address of the Internet Protocol (IP) service flow, the device reaches the ingress edge device A and the internal node D. When the edge device B is exported, the egress edge device B is required to determine that the service flow is from the ingress edge device A connected to the Host1, so that traffic flow statistics are performed on the service flow belonging to the ingress edge device A, that is, the pre-congestion flag is calculated. The business flow accounts for the proportion of all business flows from the ingress edge device A. If the ratio is significant, indicating that the risk of congestion increases, the ingress edge device A can reject the incoming traffic flow to avoid congestion on the network. Of course, the ingress edge device A can also determine that the service flow is sent to the egress edge device connected to the Host 2 according to other requirements. Here, the ingress edge device and the egress edge device are in the direction of the service flow, if The service flow is from the edge device A to the edge device B, then the edge device A is the ingress edge device, and the edge device B is the egress edge device. If the service flow is from the edge device B to the edge device A, the edge device A is the egress edge device, the edge Device B Is the entrance edge device.

In the RACF (Resource Admission Control Function) framework shown in Figure 1-b, the resource admission control function is performed on the control network element located above the transmission network, and the control network element processes the service resource request according to the service. The flow information determines the transmission unit it needs to pass, and reserves resources on the transmitted transmission unit according to the resource requirements. This means that the RACF must grasp the resource status of the transmission network domain. For example, it needs to know that it is available on a certain path in the domain. What is the resource, which means that the control network element needs to master the topology of the transmission domain and needs to know the path through which a certain service flow passes. Moreover, the RACF control network element needs to know the transmission domain entry and transmission through which the service flow passes. Domain exits. Now, the matching relationship table shown in Table 1 is usually established on the RACF using the static configuration method:

Table 1

For the edge nodes of the network transmission domain, there are currently methods for determining the ingress or egress edge devices of the service flows, and it is not possible to flexibly and conveniently determine the ingress and/or egress edge devices of the service flows in various scenarios. Summary of the invention

Embodiments of the present invention provide a method for determining an edge device to implement an ingress edge device and/or an egress edge device that conveniently determines a service flow.

Embodiments of the present invention also provide a transport network system to facilitate the determination of an ingress and/or egress edge device of a service flow.

The embodiment of the present invention further provides a control network element to implement an entry and/or an exit edge device for conveniently determining a service flow by using the control network element.

An embodiment of the present invention further provides an edge device to implement an ingress and/or egress edge device that conveniently determines a service flow by using the edge device. A method of determining an edge device, the method comprising:

The first edge device of the transmission network domain obtains the correspondence between the second edge device and the address information from the control network element, where

Corresponding relationship between the second edge device and the address information includes: a correspondence between the second edge device and the address information of the second edge device reaching the out-of-domain network, and/or the second edge device and the second edge device Correspondence of the out-of-domain address information of the service flow;

When the first edge device is processing the service flow, the first edge device determines, according to the address information in the processed service flow and the corresponding relationship, the second edge device corresponding to the processed service flow.

A transmission network system, the system comprising: a first edge device, a second edge device, and a control network element;

The control network element is configured to record a correspondence between the second edge device and the address information, where the correspondence between the edge device and the address information includes: address information of the second edge device and the second edge device reachable to the extra-domain network a corresponding relationship, and/or a correspondence between the second edge device and the out-of-domain address information of the service flow of the second edge device; the first edge device, configured to obtain the second edge device from the control network element Corresponding relationship of the address information, when the first edge device processes the service flow, the first edge device determines the second corresponding to the processed service flow according to the address information in the processed service flow and the corresponding relationship. Edge device.

A control network element, where the control network element includes: a routing relationship maintenance module and a corresponding relationship sending module;

The routing relationship maintenance module is configured to establish a correspondence between the second edge device and the address information;

And the corresponding relationship sending module is configured to send a correspondence between the second edge device and the address information to the first edge device.

An edge device, the edge device comprising:

a corresponding relationship receiving module, configured to receive a correspondence between the second edge device and the address information from the control network element, where the correspondence between the second edge device and the address information The correspondence between the second edge device and the address information of the second edge device reaching the extra-domain network, and/or the correspondence between the second edge device and the extra-domain address information of the service flow passing the second edge device;

The edge device determining module is configured to determine, according to the address information in the processed service flow and the corresponding relationship, the second edge device corresponding to the processed service flow when processing the service flow.

Compared with the prior art, the embodiment of the present invention provides a method, a system, a control network element, and an edge device for determining an edge device, where the first edge device can be based on a correspondence between the second edge device and the address information from the control network element. When the first edge device processes the service flow, the ingress and/or egress edge device corresponding to the service flow is determined, and is particularly suitable for the transmission network with an independent control layer. DRAWINGS

Figure 1-a is a schematic diagram of a PCN network in the prior art;

Figure 1-b is a schematic diagram of a RACF framework network in the prior art;

2 is a schematic structural diagram of a system according to a first embodiment of the present invention;

3 is a schematic flow chart of determining an ingress and/or an egress edge device of a service flow according to the present invention;

4 is a schematic structural diagram of a system according to a second embodiment of the present invention. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings.

2 is a schematic structural diagram of a system according to a first embodiment of the present invention. As shown in FIG. 2, the system includes: at least two edge devices 210 and a control network element 220 for centralized control of edge devices.

The control network element 220 is responsible for establishing and maintaining the correspondence between each edge device of the transport network domain and the extra-domain network address. The correspondence between the numbers may be as shown in Table 4:

Table 4

In the present invention, the extra-domain network address represents a set of host addresses located outside of the transport network domain, such as an IP network, represented as an IP network segment. This correspondence expresses a routing relationship, that is, a service flow arriving at/from an extra-domain network address passes through an edge device, and is distinguished from the corresponding relationship between the flow source/sink and the edge device described later. 2 and the following figure 4 is represented by the word "routing relationship", which are actually identical in form.

The correspondence shown in Table 4 can be established and maintained through static configuration; it can also be established and maintained through dynamic methods.

The correspondence shown in Table 4 also assumes that the traffic flow through the transport network domain is symmetric, that is, if there is an entry corresponding to the edge device 1 and the extra-domain network address 11, the traffic flow from and to the extra-domain network address 11 is indicated. All can only go through edge device 1.

When a dynamic method is used to establish a correspondence relationship as shown in Table 4 on the control network element 220, the present invention assumes that each out-of-domain network address corresponds to a unique edge device, that is, the service flow reaching the network address outside the domain is uniquely unique. The egress edge device, or traffic flow from an out-of-domain network address corresponds to a unique edge-like device.

The static configuration method can be used to establish a more complex correspondence, for example, the service flow is asymmetric, the edge device corresponding to the extra-domain network address is not unique, and so on. Table 5 illustrates a complex correspondence established on the control network element 220:

table 5

Ingress edge device egress edge device source domain out-of-network address address out-of-zone network address edge device 1 edge device 2 extra-domain network address 11 extra-domain network address 21 Edge device 2 edge device 1 extra-domain network address 22 extra-domain network address 12 control network element 220 can be established and maintained by static configuration method and dynamic method as shown in Table 4 and/or Table 5, as long as these correspondences are not available. Ambiguity can be.

The control network element 220 includes: a routing relationship maintenance module 221 and a corresponding relationship delivery module 222.

The routing relationship maintenance module 221 is responsible for maintaining the correspondence between the dynamic edge collection and the static configuration as shown in Table 4 or Table 5, and determining the correspondence between the edge device and the traffic sink based on the corresponding relationships or determining the correspondence between the ingress edge device and the flow source. .

The corresponding relationship sending module 222 sends the corresponding relationship between the ingress edge device and the flow source obtained by the routing relationship maintenance module to the egress edge device, or sends the egress edge device and the sink device obtained by the routing relationship maintenance module to the ingress edge device. Correspondence.

The edge device 210 includes: a correspondence receiving module 211 and an edge device determining module

212.

The correspondence receiving module 211 receives the correspondence between the egress edge device and the sink that is sent by the control network element 220 or the correspondence between the ingress edge device and the flow source; the edge device determining module 212 processes the inbound transmission to the ingress edge device. When the service flow of the network domain is determined, the egress edge device corresponding to the service flow is determined by the traffic sink. For the egress edge device, when processing the service flow out of the transport network domain, the flow source determines the entry corresponding to the service flow. Edge device.

FIG. 3 is a schematic diagram of the basic steps of determining an ingress and/or egress edge device of a service flow according to the present invention, as follows:

Step 301: The control network element establishes and maintains a correspondence between the extra-domain network address and the edge device.

Step 302: The control network element sends the corresponding relationship between the traffic sink and the egress edge device to the ingress edge device, and/or the control network element sends the corresponding relationship between the flow source and the ingress edge device to the egress device.

Step 303: The ingress edge device determines, according to the correspondence between the received sink and the egress edge device, the egress edge device of the service flow, and/or the egress edge device according to the receiving The corresponding relationship between the source and the ingress edge device to determine the ingress edge device of the service flow. 4 is a schematic structural diagram of a system according to a second embodiment of the present invention. In this embodiment, the resource control function (RACF, Resource Admission Control Function) is implemented on the transport resource control function entity (TRC-FE, Transport Resource Control Function Entity) to implement centralized control and management functions on the edge device. That is, the control network element 420 is a resource admission control function (RACF) entity, the transmission network domain is a PCN domain, and the edge device 410 is a router device, including three edge devices A, 8 and.

In this embodiment, the edge device 410 includes a service flow correspondence receiving module 411 and an edge device determining module 412. The function is the same as the first embodiment 211 and 212 of the present invention. The edge device A may further include: a routing relationship reporting module 414. It is responsible for the correspondence between the control network element 420 and its own network address.

The control network element 420 in this embodiment includes a routing relationship maintenance module 422 and a corresponding relationship delivery module 421, and its function is the same as that of the first embodiment of the present invention. The control network element 420 may further include: a routing relationship update module 423, configured to receive a correspondence between the edge device and the extra-domain network address, and notify the routing relationship maintenance module 422 to perform maintenance, especially when the edge device and the extra-domain network address are When the corresponding relationship changes, the edge device reports the change to the routing relationship update module 423, and the routing relationship update module 423 notifies the routing relationship maintenance module 422 to update the correspondence table as shown in Table 4.

In this embodiment, the extra-domain network address is represented by an extra-domain IP network segment indicating a group of host addresses, and the stream source and the stream sink may be represented by an extra-domain IP network segment indicating a group of host addresses, or may be an IP address. The host address indicated, and the host application address represented by the IP address plus the transport layer protocol number plus the transport layer port number.

The following describes how the control network element 420 establishes and maintains a correspondence table as shown in Table 4 through a dynamic method.

As shown in Figure 4, the out-of-domain network address that the edge device A can reach is the IP network segment 200.1.4.0/24, and the out-of-domain network address that the edge device B can reach is the IP network segment 200.1.3.0/24, and the edge device C can reach The out-of-domain network address is the IP network segment 202.0.0.0/8, 168.3.0.0/16, and the edge device A, B, and C respectively report the correspondence between the domain and the extra-domain network address to the control network element through the respective routing relationship reporting module 414. 420.

After receiving the foregoing correspondence, the routing relationship update module 423 in the control network element 420 notifies the routing relationship maintenance module 422 to establish its correspondence table as shown in Table 6 on the control network element 420:

Table 6

Of course, when an edge device such as C adds a route to the extra-domain network, for example, 210.8.0.0/16, the edge device C immediately reports the change to the control network element 420 through the routing relationship reporting module 414, and controls the network element. The routing relationship update module 423 of 420 notifies the routing relationship maintenance module 422 to establish a correspondence table as shown in Table 7 on the control network element 420: Table 7

Similarly, when an edge device 410 revokes a route to the extra-domain network, the control network element 420 also needs to revoke the corresponding relationship between the corresponding extra-domain network address and the edge device.

The following describes a specific implementation step of an ingress edge device that determines a traffic flow on an egress edge device.

First, the control network element 420 receives the service flow resource request, extracts the flow source and the traffic sink corresponding to the service flow, and determines the service flow according to the correspondence relationship as shown in Table 6 or Table 7 maintained by the routing relationship maintenance module. The ingress edge device passes through and exits the edge device. For example, if the service flow is (200.1.4.1, 202.1.1.1, 8, 100, 200), the flow source is (200.1.4.1, 8, 100), and the traffic is (202.1.1.1, 8, 200). The ingress edge device to which the stream passes is A, and the egress edge device is C.

Then, the control network element 420 sends the corresponding relationship between the flow source and the ingress edge device to the corresponding egress edge device.

For example, the correspondence between (200.1.4.1, 8, 100) and the ingress edge device, A, is sent to the egress edge device C. After the service flow correspondence receiving module 411 of the edge device C receives the service flow correspondence relationship sent by the control network element 420, the corresponding relationship shown in Table 8 is established on the edge device C:

Table 8

Then, the egress edge device processes the above service flow to determine the ingress edge device of the service flow.

For example, when the edge device C receives the service flow whose flow identifier is (200.1.4.1, 202.1.1.1, 8, 100, 200), the edge device determining module 412 of the edge device C determines the service according to the correspondence relationship shown in Table 8. The stream comes from the ingress edge device A.

When the service flow is revoked, the correspondence as shown in Table 8 is deleted from the egress edge device C.

For the second embodiment of the present invention, the step of determining the egress edge device of the service flow on the transport network domain ingress edge device is very similar to the above, and the operation to be performed is only to deliver the corresponding relationship between the sink and the egress edge device to the corresponding On the ingress edge device, the egress edge device of the service flow is determined on the ingress edge device, and is not illustrated here.

Sometimes the service flow is bidirectional and symmetrical. The correspondence shown in Table 8 not only indicates that the ingress edge device of the traffic flow from the flow source (200.1.4.1, 8, 100) is A, but also indicates the destination to the sink ( 200.1.4.1, 8, 100) The outgoing edge device of the service flow is A.

In order to maintain the integrity of the flow identifier or the policy requirements, the entire flow identifier containing the flow source and the sink may be delivered. As shown in Table 9, received on edge device C Correspondence.

Table 9

The following is a specific implementation step of determining the outbound/ingress edge device of the service flow in the transmission network domain system.

In this example, assuming that the traffic flow is bidirectionally symmetric, the system requires that the ingress edge device of the traffic flow be determined on the egress device, and that the egress edge device of the traffic flow is also required to be determined on the ingress edge.

Step 1: The control network element 420 sends the corresponding relationship between the source/sink and the edge device associated with the extra-domain network address to all other related edge devices according to the corresponding relationship shown in Table 6.

For example, for edge device A, the corresponding relationship that the control NE sends is shown in Table 10: Table 10

After a corresponding relationship is added to the control network element 420, the mapping between the source/sink and the edge device associated with the newly added extra-domain network address is sent to all other related edge devices.

For example, the control network element 420 adds a mapping between the edge device C and the extra-domain network address 210.8.0.0/16. As shown in Table 7, the control network element 420 immediately delivers the edge devices A and B, and the edge device A The correspondence is updated as shown in Table 11: Table 11

C 202.0.0.0/8, 210.8.0.0/16, 210.8.0.0/16

Similarly, after the control network element 420 4 sells a corresponding relationship, the relevant edge device is notified to delete the corresponding relationship between the stream source/sink and the edge device associated with the revoked extra-domain network address.

Step 2: When the edge device processes the service flow flowing into the transmission network domain, it acts as the ingress edge device, and determines the egress edge device according to the source and sink of the service flow. As the egress edge device, the ingress edge device is determined according to the flow source.

For example, when A is the ingress edge device receiving the service flow from 200.1.4.1 to 202.1丄 1, according to the correspondence shown in Table 12, it is determined that the ingress edge device of the service flow is C. When A is the ingress edge device receiving the service flow from 202.1.1.1 to 200.1.4.1, according to the correspondence shown in Table 12, the ingress edge device of the service flow is determined.

In this example, the stream source/sink is expressed as a converged form, consistent with the extra-domain network address form.

The following describes a resource state maintenance method that is extended by the egress device that determines the service flow.

The TRC-FE (Transport Resource Control Function Entity) in this embodiment maintains the topology and structure of the transport layer, and maintains the intra-domain topology consisting of four points A, B, C, and D. Real-time understanding of path reachability in the network domain, and real-time maintenance of the resource availability of each link or each path. For example, the reserved bandwidth value of each link can be known, so that the pre-link of each link can be known. Whether the bandwidth can meet the requirements of a business flow.

As shown in FIG. 4, the RACF corresponding to the control network element 420 in the embodiment of the present invention is functionally different from the conventional RACF, because the transmission network domain in this embodiment is a PCN domain, and the ingress edge device and the egress of the PCN domain. The pre-congestion status of the service flow can be counted between the edge devices. Using the pre-congested state as an expression of resource availability, RACF's TRC-FE does not have to maintain the topology within the network domain, but considers that the entire topology is the mesh (Mesh) connection between all edge devices. The resource form is no longer the resource state such as the reserved bandwidth of each path in the prior art, but the traffic flow statistics of each pair of ingress-egress as shown in Table 13. Import and export business flow system

Count

A B XXX

A C XXX

B A XXX

B C XXX

C A XXX

C B XXX

There are many types of service flow statistics, which can be represented by the proportion of traffic flows marked with pre-congestion in all traffic flows. If the proportion is 0, it means there is no pre-congestion, and a new service flow can be accepted at the ingress edge device. If the specific gravity is 0.5 and the preset threshold is 0.4, it means that the congestion level is more serious. Continue to accept the traffic flow at the ingress edge device will increase the congestion. At this time, it is no longer possible to accept the new service flow at the ingress edge device. .

Therefore, in the second embodiment of the present invention, if the service flow statistics need to be further performed, the egress edge device 410 may further include: a service flow statistics module 413, which is determined by the edge device determining module 412 from the same ingress edge device. The service flow performs service flow statistics, and the service flow statistics result is sent to the control network element 420.

The control network element 420 may further include: a statistical result receiving module 424, configured to receive traffic flow statistics information of the egress edge device, as a resource available state of each pair of ingress edge devices to the egress edge device in the transmission network domain, such as the congestion state described above.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by hardware, or can be implemented by means of software plus necessary general hardware platform, and the technical solution of the present invention. It can be embodied in the form of a software product that can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for making a computer device (may Is a personal computer, server, or network device, etc.)

12 The method described in various embodiments of the present invention.

In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Rights request

A method for determining an edge device, the method comprising: the first edge device of the transmission network domain obtains a correspondence between the second edge device and the address information from the control network element, where

The method for determining an edge device according to claim 1, wherein the method is: before the control network element provides a correspondence between the second edge device and the address information of the first edge device, the method Further includes:

The control network element receives the out-of-domain network address information that is reachable by the second edge device that is actively reported by the second edge device, or queries the second edge device to obtain the reachability of the second edge device itself. Extra-domain network address information;

The control network element establishes a correspondence between the second edge device and the extra-domain network address information reachable by the second edge device.

The method for determining an edge device according to claim 2, wherein the method is: before the control network element provides a correspondence between the second edge device and the address information of the first edge device, the method Further includes:

The control network element extracts, from the received service flow request, the address information of the service flow; and establishes, according to the correspondence between the pre-established second edge device and the address information of the second edge device reachable extra-domain network, The correspondence between the out-of-domain address information of the service flow of the edge device and the second edge device.

The method for determining an edge device according to claim 2, wherein the method further comprises: when the second edge device adds or deletes an external route, The second edge device actively reports the out-of-domain network address information that is reachable by the second edge device to the control network element, and the control network element updates the second edge device according to the extra-domain network address information. Correspondence with address information.

The method for determining an edge device according to claim 1, wherein the determining the second edge device corresponding to the processed service flow comprises:

The first edge device determines the ingress edge device of the service flow according to the source address information in the service flow and the corresponding relationship between the second edge device and the address information, or the first edge device according to the destination address in the service flow The information and the correspondence between the second edge device and the address information determine an exit edge device of the service flow.

The method for determining an edge device according to claim 1, wherein the correspondence relationship is a correspondence between the second edge device and the out-of-domain address information of the service flow of the second edge device, After the second edge device corresponding to the processed service flow, the method further includes:

After the service flow is revoked, the first edge device deletes the correspondence between the second edge device and the out-of-domain address information of the service flow of the second edge device.

The method for determining an edge device according to claim 1, 2, 3, 4, 5 or 6, wherein the address information comprises: a network address representing a group of hosts, a host address, or a host IP address. , the transport layer protocol number, the host application address determined by the transport layer port number.

The transmission network system according to claim 8, wherein the control network element comprises:

a routing relationship maintenance module, configured to establish a correspondence between the second edge device and the address information;

The corresponding relationship sending module is configured to send a correspondence between the second edge device and the address information to the first edge device.

10. The transmission network system according to claim 8, wherein the first edge device comprises:

a corresponding relationship receiving module, configured to receive a correspondence between the second edge device from the control network element and the address information;

A control network element, wherein the control network element comprises: a routing relationship maintenance module and a corresponding relationship delivery module;

The control network element according to claim 11, wherein the control network element further comprises:

The correspondence update module is configured to receive a correspondence between the unreachable extra-domain network addresses that are reported by the second edge device, where the extra-domain network address is an extra-domain network address corresponding to the external route added or 4 sold by the edge device .

The control network element according to claim 11, wherein the control network element comprises: a transmission resource control function entity RACF.

14. An edge device, the edge device comprising: