CN106302154B - Method and device for calculating cross-level path of IS-IS protocol - Google Patents

Method and device for calculating cross-level path of IS-IS protocol Download PDF

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CN106302154B
CN106302154B CN201510261399.3A CN201510261399A CN106302154B CN 106302154 B CN106302154 B CN 106302154B CN 201510261399 A CN201510261399 A CN 201510261399A CN 106302154 B CN106302154 B CN 106302154B
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identification data
route identification
cross
layer
path
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CN106302154A (en
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吴强
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ZTE Corp
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ZTE Corp
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/02—Topology update or discovery
    • H04L45/04—Interdomain routing, e.g. hierarchical routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/02—Topology update or discovery

Abstract

The invention discloses a method and a device for computing an IS-IS protocol cross-level path, wherein the method comprises the following steps: the intermediate network equipment in two layers leaks the route identification data of one layer to all the network equipment of the other layer; when network equipment of any one of two layers is used as a source node to receive a path calculation request, determining whether cross-layer path calculation is carried out or not by using destination route identification data in the request; if the cross-layer path calculation is determined, determining loose nodes for the cross-layer path calculation by using the destination route identification data in the request; and performing cross-layer path calculation by using the determined loose nodes. The invention eliminates the disadvantages of artificial configuration and successful calculation of the cross-level tunnel path which cannot be dynamically adapted to network changes caused by artificial configuration, and can calculate the cross-level optimal tunnel path according to the current network state.

Description

Method and device for calculating cross-level path of IS-IS protocol
Technical Field
The present invention relates to a network device for running an Intermediate System to Intermediate System routing protocol (ISIS), and in particular, to a method and an apparatus for calculating an ISIS protocol cross-level path.
Background
ISIS is a dynamic, link state based Interior Gateway Protocol (IGP). After the ISIS protocol establishes the neighborhood through hello message interactive negotiation, each Intermediate System (IS) generates a Link-State protocol data Packet (LSP) to describe Link State information of the IS and sends the Link-State Packet (LSP) to the network, and also stores LSPs sent by all IS devices on the network topology to form a Link State DataBase (Link State DataBase, LSDB). In Traffic Engineering (TE), an LSDB used by ISIS is called a Traffic engineering Link state database (TE-LSDB), and an optimal tunnel path to a destination node is calculated by a Constrained Shortest Path First (CSPF) algorithm according to the TE-LSDB.
The Resource Reservation Protocol (RSVP-TE) based on Traffic engineering is a Traffic engineering technology based on Multi-Protocol Label Switching (MPLS). The service traffic is forwarded in the TE tunnel through four components of information issuing, path calculation, signaling interaction (RSVP-TE) and traffic forwarding.
The calculation of the RSVP-TE tunnel is based on the TE-LSDB of ISIS, and is roughly divided into two types in the path calculation process, wherein one type is dynamic path calculation, and the other type is explicit path calculation through configuration. Dynamic path computation is a path computation mechanism without other constraint conditions, and only one path can meet the resources required by tunnel establishment. If the path is dynamically calculated, CSPF calculation is submitted once at the head node, and a complete path from the tunnel head node to the tunnel tail node is calculated. Explicit path computation is a computation mechanism with configuration constraints, where a tunnel path may be configured to exclude an interface or node, and where a tunnel may be configured to pass through an interface or node strictly or loosely. If the PATH is an explicit PATH calculation PATH, when the tunnel head node submits the CSPF calculation, the PATH from the tunnel head node to the first loose point in the display PATH is calculated (if the display PATHs are all strictly configured, the complete PATH from the tunnel head node to the tunnel tail node is also calculated), and when the PATH message reaches the first loose point, the CSPF calculation is performed again to the next loose point, so that the tunnel tail node is finally calculated.
The ISIS protocol is a hierarchical (level) routing protocol and is divided into two levels, namely level1 and level 2: a domain formed by level2 is a backbone domain, and the formed ISIS topology is level2 topology; the level2 network is connected to a plurality of areas (areas) on the network, and the ISIS topology formed by each area is level1 topology. And each level topology independently carries out neighbor establishment and LSP flooding to form respective TE-LSDB. Therefore, a plurality of level1 topologies formed by each area are isolated from each other by the level2 topologies of the backbone domains, and the TE-LSDB is also isolated from each other, so that the link state information of other domains or areas is not known. If RSVP-TE requires to compute a tunnel path across levels (levels) in the ISIS protocol topology, such as: the tunnel path has a first portion at level1 and a second portion at level 2. Then, dynamic calculation of the route from the head node at level1 to the tail node at level2 cannot be used. At this time, an explicit path calculation path set manually is usually adopted, and a loose node is configured to the boundary of level1 and level2 and simultaneously supports the routers of level1 and level2, so that the head node in level1 calculates to the loose node by using the TE-LSDB of level1, and the loose node calculates to the tail node in level2 by using the TE-LSDB of level 2.
At this time, there are problems as follows:
1. the tunnel paths in the network are very large, loose nodes meeting the conditions are configured one by one, and the configuration and maintenance labor cost is too high;
2. the manual configuration is easy to make mistakes;
3. when a plurality of routers supporting level1 and level2 exist at the boundary of level1 and level2, the manual configuration may not select the optimal tunnel path loose node.
Disclosure of Invention
The invention aims to provide a method and a device for calculating a cross-level path of an IS-IS protocol, which can better solve the problem of automatically calculating the optimal cross-level tunnel path which can meet the requirement under the condition of no need of human intervention.
According to one aspect of the invention, a method for computing a cross-level path in IS-IS protocol IS provided, which comprises the following steps:
the intermediate network equipment in two layers leaks the route identification data of one layer to all the network equipment of the other layer;
when network equipment of any one of two layers is used as a source node to receive a path calculation request, determining whether cross-layer path calculation is carried out or not by using destination route identification data in the request;
if the cross-layer path calculation is determined, determining loose nodes for the cross-layer path calculation by using the destination route identification data in the request;
and performing cross-layer path calculation by using the determined loose nodes.
Preferably, the step of leaking the routing identification data of one layer to all the network devices of the other layer by the intermediate network device in two layers simultaneously comprises:
the intermediate network equipment in two layers adds the route identification data of one layer to the link state data packet of the other layer and leaks the link state data packet to the other layer in a flooding mode.
Preferably, before the source node receives the path computation request, the method further includes:
the source node receives a link state data packet leaked by the intermediate network equipment in a flooding mode;
and identifying the route identification data in the link state data packet as leaked route identification data, and storing the route identification data in a link state protocol database.
Preferably, the step of determining whether to perform cross-layer path computation by using the destination route identification data in the request includes:
the source node judges whether the destination route identification data in the path calculation request is leaked route identification data or not by searching a link state protocol database of the source node;
and if the destination route identification data is judged to be the leaked route identification data, determining to perform cross-layer path calculation.
Preferably, the step of determining a loose node for cross-layer path computation using the destination route identification data in the request comprises:
and the source node searches for the intermediate network equipment which reveals the routing identification data, and determines the found intermediate network equipment as a loose node.
According to another aspect of the present invention, there IS provided an apparatus for IS-IS protocol cross-hierarchy path computation, including:
the leakage module is arranged on the middle network equipment in two layers at the same time and used for leaking the routing identification data of one layer to all the network equipment of the other layer;
a cross-level determining module, when a network device in any one of two levels receives a path calculation request as a source node, determining whether to perform cross-level path calculation by using destination route identification data in the request;
a loose node determination module, configured to determine a loose node used for calculating a cross-layer path by using the destination route identification data in the request when determining to perform cross-layer path calculation;
and the path calculation module is used for performing cross-layer path calculation by using the determined loose nodes.
Preferably, the leakage module adds the route identification data of one layer to the link state data packet of another layer, and leaks the link state data packet to another layer in a flooding manner.
Preferably, the method further comprises the following steps:
and the link state protocol database is used for storing the route identification data in the link state data packet leaked by the leakage module before receiving the path calculation request and identifying the route identification data as the leaked route identification data.
Preferably, the cross-level determining module determines whether the destination route identification data in the path calculation request is the leaked route identification data by searching a link state protocol database thereof, and determines to perform cross-level path calculation if the destination route identification data is the leaked route identification data.
Preferably, the loose node determining module searches for an intermediate network device that reveals the route identification data, and determines the found intermediate network device as a loose node.
Compared with the prior art, the invention has the beneficial effects that:
1. the tunnel path can automatically perform cross-level calculation, a loose path does not need to be configured manually, and the labor configuration cost is reduced;
2. because of the change of the network, the original cross-layer path calculation needs to manually reconfigure the loose path, but by using the invention, the cross-layer tunnel path can automatically adapt to the dynamic change of the network, and the cross-layer tunnel path meeting the requirement is recalculated, thereby avoiding the problem of manual configuration error;
3. the original cross-layer path calculation needs to manually reconfigure a loose path, the manual configuration is not necessarily the optimal path of the current network, and after the invention is used, the path is automatically calculated according to the CSPF algorithm, and the cross-layer optimal path meeting the requirement can be calculated.
Drawings
FIG. 1 IS a schematic block diagram of a method for computing a cross-level path in an IS-IS protocol according to an embodiment of the present invention;
FIG. 2 IS a block diagram of an apparatus for cross-level path computation of the IS-IS protocol provided by an embodiment of the present invention;
FIG. 3is a leaky TE router-id TLV diagram provided by an embodiment of the invention;
fig. 4is a cross-layer path computation topology diagram provided by the embodiment of the present invention.
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described below are only for the purpose of illustrating and explaining the present invention, and are not to be construed as limiting the present invention.
Fig. 1 IS a schematic block diagram of a method for calculating a cross-layer path in an IS-IS protocol according to an embodiment of the present invention, and as shown in fig. 1, the steps include:
step S101: the intermediate network devices at both levels simultaneously leak the route identification data of one level to all network devices of the other level.
Specifically, the intermediate network device in two layers adds the route identification data of one layer to the link state data packet of the other layer, and leaks the link state data packet to the other layer in a flooding manner, so that the network device in the other layer receives the link state data packet leaked by the intermediate network device in the flooding manner, and identifies the route identification data in the link state data packet as the leaked route identification data, and stores the leaked route identification data in the link state data packet in the link state protocol database. One link state data packet may carry multiple routing identification data of one level.
Step S102: when network equipment of any one of the two layers is used as a source node to receive a path calculation request, destination route identification data in the request is used for determining whether cross-layer path calculation is carried out or not.
Specifically, the source node searches its link state protocol database to determine whether the destination route identification data in the path calculation request is the leaked route identification data, and if the destination route identification data is found in the link state protocol database and is identified as the leaked route identification data, it indicates that the network device corresponding to the destination route identification data is not the network device of the level where the source node is located, and cross-level path calculation needs to be performed.
If the destination route identification data is found in the link state protocol database and is identified as the non-leakage route identification data, it is indicated that the network device corresponding to the destination route identification data is the network device of the layer where the source node is located, and the tunnel path calculation is directly performed.
Step S103: and if the cross-layer path calculation is determined, determining loose nodes for the cross-layer path calculation by using the destination route identification data in the request.
Specifically, the source node searches for an intermediate network device that reveals the route identification data, and determines the found intermediate network device as a loose node.
Step S104: and performing cross-layer path calculation by using the determined loose nodes.
Fig. 2 IS a block diagram of an apparatus for calculating a cross-layer path in IS-IS protocol according to an embodiment of the present invention, as shown in fig. 2, including: the leakage module 10 provided at an intermediate network device in both layers, the cross-layer determining module 20 provided at a network device in any one of the two layers, the loose node determining module 30, and the path calculating module 40.
The leakage module 10 is configured to leak the routing identification data of one layer to all network devices of another layer, and specifically, the leakage module 10 adds the routing identification data of one layer to the link state data packet of another layer and leaks the link state data packet to another layer in a flooding manner. At this time, the network device at another level receives the link state data packet leaked by the intermediate network device in a flooding manner, and identifies the route identification data in the link state data packet as the leaked route identification data, and stores the route identification data in the link state data packet to the link state protocol database thereof, in other words, the network device further includes a link state protocol database (not shown in the figure), which is used for storing the route identification data in the link state data packet leaked by the leakage module 10 and identifying the route identification data as the leaked route identification data before receiving the path calculation request.
When a network device where the cross-layer determination module 20 is located receives a path calculation request as a source node, the cross-layer determination module 20 determines whether to perform cross-layer path calculation by using destination route identification data in the request, specifically, the cross-layer determination module 20 determines whether the destination route identification data in the path calculation request is leaked route identification data by searching a link state protocol database of the cross-layer determination module, and if the destination route identification data is found in the link state protocol database and is identified as the leaked route identification data, it indicates that the network device corresponding to the destination route identification data is not a network device of a layer where the source node is located, and at this time, it is determined that cross-layer path calculation is required; if the destination route identification data is found in the link state protocol database and is identified as the non-leakage route identification data, it is indicated that the network device corresponding to the destination route identification data is the network device of the level where the source node is located, and at this time, it is determined that cross-level path calculation is not needed, that is, tunnel path calculation is directly performed.
The loose node determining module 30 is configured to, when determining to perform cross-layer path calculation, determine a loose node used for the cross-layer path calculation by using the destination route identification data in the request, specifically, the loose node determining module 30 searches for an intermediate network device that leaks the route identification data, and determines the found intermediate network device as a loose node.
And the path calculation module is used for performing cross-layer path calculation by using the determined loose nodes.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to fig. 3 and 4.
A new protocol type data TLV (type-length-value) carried in LSP
Fig. 3is a graph of a leaky TE router-id TLV according to an embodiment of the present invention, and as shown in fig. 3, a new protocol type data TLV, called TE router-id leaky TLV, is added, where the new protocol type data TLV includes a type of one byte and a length of one byte, and a value includes multiple TE router-ids, and each TE router-id is 6 bytes. Thus, the length in the length field is 6 × n, n representing the number of TE router-ids contained in the value field.
Any one LSP packet may contain multiple TE router-id leakage TLVs.
Second, the processing method
1. And if Level1 and Level2 enable are set, MPLS Level1 and Level2 functions are set to be opened, and TE router-id leaks from Level2 to Level1, the generation party IS enables TE router-id of all IS leaking in the Level2 topology to be in Level1, places the leaked TE router-id in a TE router-id leakage TLV, adds the TE router-id leakage TLV to LSP of Level1, and floods the LSP finally. And the TE router-ids of all the IS in the Level2 topology are processed through router id TLV carried by the LSP generated by all the IS in the received Level2 topology, and the TE router id configured by the IS stored in the TLV IS extracted.
2. Similarly, if the generation party IS sets Level1 and Level2 to be enabled, sets MPLS Level1 and Level2 functions to be opened at the same time, and sets TE router-id to leak from Level1 to Level2, the generation party IS leaks TE router-id of all IS in the Level1 topology into Level2, places the leaked TE router-id into a TE router-id leakage TLV, adds the TE router-id leakage TLV into LSP of Level2, and finally floods the LSP. And TE router-ids of all IS in the Level1 topology are processed through router id TLV carried by LSP generated by all IS in the received Level1 topology, and TE router ids configured by the stored IS are extracted to obtain the TE router-ids.
3. And the calculating part IS receives the LSP sent by the generating part IS, and the TE router-id TLV IS stored in the LSP, so that the TE router-id in the TE router-id TLV IS stored and identified as the non-leakage TE router-id. This non-leaked TE router-id IS the TE router-id configured by IS of the generating party, and each IS configures a TE router-id as a unique identifier in the TE network.
4. And the calculating part IS receives the LSP sent by the generating part IS, and the LSP stores the TE router-id leakage TLV, so that the TE router-id in the TE router-id leakage TLV IS stored and identified as the leaked TE router-id. The leaked TE router-id exists in the LSP of the generating IS, but IS not the TE router-id configured by the generating IS, and IS not used as a unique identifier of the generating IS in the TE network, but only represents that the generating IS can reach the IS identified by the TE router-id in the level topology where the generating IS located.
5. The calculation part IS receives the tunnel path calculation request of RSVP, needs to judge the existence condition of the destination TE router-id, if the corresponding TE router-id can be found in the Level of the calculation part IS and IS the non-leakage TE router-id, the tunnel path calculation IS directly carried out, no judgment IS needed in the calculation process, and the destination can be directly calculated under the condition.
6. And the calculating party IS receives the tunnel path calculation request of the RSVP and needs to judge the existence condition of the destination TE router-id, and if the corresponding TE router-id can be found in the Level of the calculating party IS and IS the leaked TE router-id, the tunnel path calculation IS carried out. When an IS IS calculated, judging whether the IS has a leaked TErouter-id as the destination TE router-id, if not, calculating the IS tunnel path of the calculating party to continue; if yes, the IS of the calculating party automatically sets the tunnel path to be loose to the TE router-id of the IS, and the IS tunnel path calculation of the calculating party IS finished. Subsequently, after tunnel establishment to this IS by RSVP, the remaining tunnel path calculation IS again submitted to eventually reach the destination, the route-id.
In summary, the ISIS protocol IS a hierarchical routing protocol, which IS divided into two levels of level1 and level2, and IS located in the generation IS of level1 and level2, and fills the non-leakage router-ids configured by all IS acquired on a level network topology in a new type of TE router-id leakage TLV, and carries the TLV to the LSP of another level, where the level IS flooded. During the tunnel path calculation in one level by the calculating party IS, when the generating party IS of one level1 and level2 IS calculated, whether the destination of the calculation IS the TE router-id leaked by the IS IS checked, if so, the non-leaked TE router-id set by the IS IS automatically set to be the loose node TE router-id, and the cross-level tunnel path calculation IS realized. Not only eliminates the disadvantages of artificial configuration and successful calculation of the cross-level tunnel path which is caused by the artificial configuration and can not dynamically adapt to the network change, but also can calculate the cross-level optimal tunnel path according to the current network state.
Fig. 4is a cross-layer path computation topology diagram provided by the embodiment of the present invention, and two specific embodiments are given below in conjunction with fig. 4 to further explain the present invention.
The first embodiment is as follows:
as shown in fig. 4, in a network composed of R1, R2, R3, and R4, R1, R2, and R3 form a region, which is a Level1 region, and establish a Level1 neighbor relationship with each other, and R2 and R4 establish a Level2 backbone region and establish a Level2 neighbor relationship. It is apparent that R2 is in the Level1 region and also in the Level2 shaft region. The TE router-ids of the R1, R2, R3 and R4 intermediate systems are respectively 1.1.1.1, 2.2.2.2, 3.3.3.3 and 4.4.4.4 and serve as unique identifiers in the TE network. Obviously, the level1 function of R1, R2 and R3ISIS is started, and the level1 function of MPLS is started at the same time. R2, the level2 function of R4ISIS is started, and simultaneously the level2 function of MPLS is started. R2 is a router of Level1/Level2, and the MPLS function of Level1/Level2 is enabled. Suppose a tunnel is currently configured to calculate an arrival destination of 4.4.4.4 from router-id1.1.1, i.e., a tunnel from R1 to R4.
According to the requirements of the original protocol, the level of R1 is level1, only the LSP database of the level1 in the region is owned, namely only the link state information of the level1 of R2 and R3. There is no level 2LSP database for R3 and R4, i.e., there is no link state information for the different level levels level2 of R2 and R3. The tunnel path calculation by R1 can only be calculated to R2 and R3. Therefore, if one wishes to establish a path from R1 to R4, i.e., from router-id1.1.1.1 to router-id4.4.4.4, one must manually configure R2 as a loose path, which is loose to router-id 2.2.2.2 of R2. Thus, R1 first calculates the tunnel path to R2, and RSVP first establishes the tunnel from R1 to R2. The R2 has an LSP database of level1 and an LSP database of level2, then the calculation of the tunnel path reaching router-id4.4.4 is initiated again on R2, the calculation of the tunnel path is carried out in level2 by using the LSP database of level2 to reach R4 of router-id4.4.4, and the residual tunnel reaching R4 from R2 is reestablished by RSVP. Thus, the calculation of the tunnel path across the layers is completed and the establishment is successful. In this method, the loose router-id 2.2.2.2 of the tunnel must be manually configured, that is, the tunnel must pass through R2.
After the invention is used, R2 is a router of Level1 and Level2, the MPLS functions of Level1 and Level2 are simultaneously opened, and the leakage of TE router-id from Level2 to Level1 is configured on R2. The level 2LSP database of R2 stores all LSP messages of R2 and R4, and after the processing of the level 2LSP database, the TE router-id 2.2.2.2 of the level 2R2 is stored and identified as non-leakage TE router-id, and the TE router-id4.4.4 of the level 2R 4is stored and identified as non-leakage TE router-id. Then, Level2TE router-id4.4.4.4 of R4is placed in the TE router-id leakage TLV, which is added to the Level 1LSP of R2 (generator intermediate system), and this Level 1LSP is flooded.
And R1 IS a calculator IS, and receives LSPs generated by all the ISs of the network topologies R1, R2 and R3 of the level1 where the calculator IS IS located to form a link state database of the level 1. Similarly, the TE router-id 2.2.2.2 of level 1R2 is stored and marked as non-leakage TE router-id through LSP database processing of level 1; the TERouter-id 3.3.3.3 of level 1R 3is stored and marked as non-leakage TE Router-id; the TE router-id1.1.1.1 of level 1R1 is saved and identified as the non-leaking TE router-id. Meanwhile, when the Level 1LSP generated by the R2 is processed, the existence of a leaked TE router-id TLV is found, wherein the TE router-id TLV comprises a TE router-id4.4.4.4, which is the TE router-id of the R4 on the Level2 topology, and the leaked TE router-id is stored.
Upon receiving the RSVP calculation request, the calculating party IS R1 finds that the TE router-id4.4.4.4 of destination R4IS calculated from the TE router-id1.1.1 of R1. The destination TE router-id is looked up 4.4.4.4 and found to be a leaked TE router-id. And starting tunnel path calculation, and judging whether the destination TE router-id4.4.4.4 IS the TE router-id leaked by any IS once when any IS IS calculated. In this example, R2 with TE router-id of 1.1.1.1 IS calculated, and the search finds that R2 leaks TE router-id4.4.4.4, then this tunnel path IS automatically set to calculate loose router-id of 2.2.2.2, and the tunnel path of the calculating party IS R1 ends. RSVP establishes a tunnel from R1 to R2 and initiates tunnel path computation again on R2, the destination is 4.4.4.4, computation can be completed when using the link state database computation of level2, and then the entire cross-level path computation across level1 to level2 is completed and established successfully.
Example two:
as shown in fig. 4, in a network composed of R1, R2, R3, and R4, R1, R2, and R3 form a region, which is a Level1 region, and establish a Level1 neighbor relationship with each other, and R2 and R4 establish a Level2 backbone region and establish a Level2 neighbor relationship. It is apparent that R2 is in the Level1 region and also in the Level2 shaft region. The TErouter-ids of the R1, R2, R3 and R4 intermediate systems are 1.1.1.1, 2.2.2.2, 3.3.3.3 and 4.4.4.4 respectively, which are used as unique identifiers in TE networks. Obviously, the level1 function of R1, R2 and R3ISIS is started, and the level1 function of MPLS is started at the same time. R2, the level2 function of R4ISIS is started, and simultaneously the level2 function of MPLS is started. R2 is a router of Level1/Level2, and the MPLS function of Level1/Level2 is enabled. Suppose a tunnel is currently configured to calculate from router-id4.4.4.4 a tunnel with a destination of 1.1.1.1, i.e., a tunnel from R4 to R1.
After the invention is used, R2 is a router of Level1 and Level2, the MPLS functions of Level1 and Level2 are simultaneously opened, and the leakage of TE router-id from Level1 to Level2 is configured on R2. The LSP database of level1 of R2 stores all LSP messages of R1, R2 and R3, the TE router-id 2.2.2.2 of level 1R2 is stored and identified as non-leakage TE router-id through the LSP database processing of level1, and the TE router-ids 1.1.1.1 and 3.3.3.3 of level 1R1 and R3 are stored and identified as non-leakage TE router-id. Then, Level 1TE router-id1.1.1.1 and 3.3.3.3 of R1 and R3 are placed in a TE router-id leakage TLV, which is added to the Level 2LSP of R2 (generator intermediate system) and floods this Level2 LSP.
R4IS a calculator IS, and receives LSPs generated by all IS of the level2 network topology R2 and R4 where the calculator IS IS located to form a level2 link state database. Similarly, the TE router-id 2.2.2 of level 2R2 and the TE router-id4.4.4.4 of R4 are stored and marked as non-leakage TE router-id through the LSP database processing of level 2; meanwhile, when the level 2LSP generated by the R2 is processed, the leakage TE router-id TLV is found to exist, and the TE router-id1.1.1.1 and 3.3.3 issued by the level 2R2 in the LSP are stored and identified as the leakage TE router-id.
Upon receiving the RSVP calculation request, R4 finds that the TE route-id 1.1.1.1 arriving at the destination R1 is calculated from TE route-id 4.4.4.4 of R4. The destination TE router-id1.1.1.1 is looked up and found to be a leaked TE router-id. Starting tunnel path calculation, and executing a judgment once when any IS (intermediate system) IS calculated, and judging whether the destination TE router-id1.1.1.1 IS the TE router-id leaked by the IS. In this example, R2 with TERouter-id of 1.1.1.1 IS calculated, and the search finds that R2 leaks TE Router-id1.1.1.1, then this tunnel path IS automatically set to calculate loose Router-id of 2.2.2.2, and the tunnel path of the calculating party IS R4 ends. RSVP establishes a tunnel from R4 to R2 and initiates the tunnel path computation again on R2, the destination is 1.1.1.1, the computation can be completed when using the link state database computation of level1, and then the entire cross-level path computation across level2 to level1 is completed and established successfully.
The invention is suitable for various devices supporting ISIS, including routers, switches and the like.
Although the present invention has been described in detail hereinabove, the present invention is not limited thereto, and various modifications can be made by those skilled in the art in light of the principle of the present invention. Thus, modifications made in accordance with the principles of the present invention should be understood to fall within the scope of the present invention.

Claims (10)

1. A method for computing a cross-layer path in an IS-IS protocol, comprising:
the intermediate network equipment in two layers leaks the route identification data of all the network equipment in one layer to all the network equipment in the other layer;
when any network device in the other layer is used as a source node to receive a path calculation request, determining whether cross-layer path calculation is carried out or not by using destination route identification data in the request and leaked route identification data of all network devices in the one layer;
and if the cross-layer path calculation is determined, determining loose nodes for the cross-layer path calculation by using the destination route identification data in the request so as to perform the cross-layer path calculation by using the determined loose nodes.
2. The method of claim 1, wherein the step of the intermediate network device at both levels leaking the routing identification data of all network devices at one level to all network devices at the other level comprises:
the intermediate network device in two layers adds the route identification data of all network devices in one layer to the link state data packet in the other layer, and leaks the link state data packet to the other layer in a flooding mode.
3. The method of claim 2, wherein before the source node receives the path computation request, further comprising:
the source node receives a link state data packet leaked by the intermediate network equipment in a flooding mode;
and identifying the route identification data in the link state data packet as leaked route identification data, and storing the route identification data in a link state protocol database.
4. The method of claim 3, wherein the step of determining whether to perform the cross-tier path computation using the destination route identification data in the request and the leaked route identification data of all network devices of the one tier comprises:
the source node judges whether the link state protocol database has the route identification data which is consistent with the destination route identification data in the path calculation request and is marked as leakage by searching the link state protocol database;
and if judging that the route identification data which is consistent with the destination route identification data and is identified as the leaked route identification data exists, determining to perform cross-layer path calculation.
5. The method of claim 4, wherein the step of determining a loose node for use in cross-tier path computation using the destination route identification data in the request comprises:
and the source node searches for the intermediate network equipment which reveals the routing identification data, and determines the found intermediate network equipment as a loose node.
6. An apparatus for IS-IS protocol cross-level path computation, comprising:
the leakage module is arranged on the middle network equipment in two layers at the same time and used for leaking the routing identification data of all the network equipment in one layer to all the network equipment in the other layer;
a cross-hierarchy determining module, configured to determine whether to perform cross-hierarchy path computation by using destination route identification data in the request and leaked route identification data of all network devices in the one hierarchy when any network device in the other hierarchy receives a path computation request as a source node;
and the loose node determining module is used for determining a loose node for cross-layer path calculation by using the destination route identification data in the request when determining to perform cross-layer path calculation, so that the determined loose node is used for performing cross-layer path calculation.
7. The apparatus of claim 6, wherein the means for leaking adds routing identification data for all network devices of one tier to link state packets of another tier and leaks the link state packets to another tier in a flooding manner.
8. The apparatus of claim 7, further comprising:
and the link state protocol database is used for storing the route identification data in the link state data packet leaked by the leakage module before receiving the path calculation request and identifying the route identification data as the leaked route identification data.
9. The apparatus according to claim 8, wherein the cross-level determining module determines whether there is a leaked route identification data consistent with the destination route identification data in the path computation request in the link state protocol database by looking up its link state protocol database, and determines to perform cross-level path computation if it is determined that there is a leaked route identification data consistent with the destination route identification data.
10. The apparatus of claim 9, wherein the loose node determination module finds an intermediate network device that divulges the route identification data and determines the found intermediate network device as a loose node.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1949744A (en) * 2005-10-14 2007-04-18 华为技术有限公司 Method for implementing PCE discovery protocol
CN101247322A (en) * 2007-02-14 2008-08-20 华为技术有限公司 Method and network appliance for route computation between autonomy systems

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9270574B2 (en) * 2013-01-09 2016-02-23 Avaya Inc. Method and apparatus providing delayed path calculations based on service type

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1949744A (en) * 2005-10-14 2007-04-18 华为技术有限公司 Method for implementing PCE discovery protocol
CN101247322A (en) * 2007-02-14 2008-08-20 华为技术有限公司 Method and network appliance for route computation between autonomy systems

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