Ldp and igp synchronisation for broadcast networks. RU patent 2521092.

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to setting up networks and more specifically to synchronisation of a label distribution protocol (LDP) and an interior gateway protocol (IGP) for broadcast networks without causing non-optimum traffic rejection. A broadcast interface is used to carry traffic on a label-switched path. If an alternative path exists, the broadcast interface will not be declared a broadcast network until LDP becomes operational for all neighbours on the broadcast interface.

EFFECT: invention discloses an element having a broadcast interface to a broadcast network which in turn becomes operational, determines if at least one alternative path to the broadcast network exists.

21 cl, 8 dwg

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] On this application claims the priority of the Provisional Application of the U.S. 61/157501, filed March 04, 2009, which is incorporated into this description by reference.

THE LEVEL OF TECHNOLOGY

The technical field to which the invention relates

[0002] embodiments of the invention relates to the field of networking and, more specifically, to the synchronization LDP (Protocol Distribution Labels) and IGP (Protocol Interior Gateway) used for the broadcast networks.

The level of technology

[0003] LDP (described in the "Specifications LDP", RFC 5036, October, 2007), which is used to create LSP (ways switched labels) to destinations, as a rule, based on the IGP (for example, the Protocol of Primary Open Shortest Paths (OSPF) (defined in "OSPF Version 2, 54 STD, RFC 2328, April, 1998), the Protocol intermediate system - intermediate system (is-is) (defined in "Intermediate system to intermediate system intra-domain routing routine information exchange protocol for use in conjunction with the protocol for providing the which are connectionless-mode Network Service (ISO 8473)", ISO standard 10589, 1992) and etc) to provide basic information routing (for example, metrics costs between the switch in the network). Even though the LDP, as a rule, based on the IGP, they are independent from each other. IGP may be working on the line before the line of communication will work LDP, which can lead to the loss of the package.

[0004] Invitation for comments (RFC) 5443, "LDP IGP Synchronization", March, 2009 (hereinafter, "the Synchronization of the LDP and the IGP) describes a mechanism to prevent the use of communication for IP forwarding, if IDP is not fully work on this line. RFC 5443 describes that when the LDP is not fully work on a given line (for example, had not been exchanged by all bindings labels), IGP will declare the communication line with the maximum cost to impede traffic is sent on the wire. When the LDP will be working on the line (for example, will share all the bindings labels), IGP declares the communication line with the right cost.

[0005] In broadcast communication lines (if there is more than one peer LDP/IGP on the same line), instead of individual cost for each peer, IGP announces total costs for broadcast communication lines. In the network can be implemented broadcast pseudouser to reduce the number of lines of a database of priority shortest paths (SPF) (for example, primary open shortest paths (OSPF), limited priority shortest paths (CSPF)) each network element. Each network element forms the contiguity with broadcast pseudoatom and declares the communication line and the cost of the broadcast pseudouser, and broadcast pseudouser declares the communication line and the cost of each network element.

[0006] in Regard to the broadcast communication lines, RFC 5443 "Synchronization LDP and IGP" describes that the mechanism can be applied to lines of communication as a whole and not to a single peer. The announcement of the maximum cost for lines of communication as a whole may cause sub-optimal deviation of traffic and/or ignoring traffic (for example, VPN traffic).

BRIEF DESCRIPTION OF DRAWINGS

[0007] the Invention can be best understood by reference to the following descriptions and accompanying drawings that are used to illustrate the embodiments of the invention. The drawings:

[0008] Figure 1 shows the approximate broadcast network according to one embodiment of the invention;

[0009] Figure 2 is a block diagram sample network element configured to synchronize LDP-IGP for broadcast networks in accordance with one of the embodiment of the invention;

[0010] Figure 3 is a flowchart illustrating the approximate synchronization operations LDP-IGP for broadcast networks in accordance with one of the embodiment of the invention;

[0011] Figure 4 is a block diagram that illustrates the approximate operation when the sync LDP-IGP completed in accordance with one of the embodiment of the invention;

[0012] Figure 5A shows the approximate local interface structure IGP according to one embodiment of the invention;

[0013] Figure 5B shows the approximate state database communication lines in accordance with one of the embodiment the invention;

[0014] Figure 6 is a block diagram that illustrates the approximate operation when a network element is ready to update your ad state lines of communication with the help of the interface to the broadcasting network in accordance with one of the embodiment of the invention; and

[0015] Figure 7 shows a sample network element used in some embodiments of the invention.

DETAILED DESCRIPTION

[0016] In the following description outlines numerous specific details. However, it must be clear what ways of implementation of the invention may be applied in practice without these specific details. In other cases, well-known pattern, structure and methodology were not shown in detail, so as not to distract from understanding of this description. Specialist in this field with the included descriptions will be able to implement functionality without undue experimentation.

[0017] Reference to specifications on the "one version of the exercise, variant of implementation", "a sample implementation", etc. indicate that this describes an implementation option involves the trait, structure or characteristic, but each option exercise does not necessarily include specific characteristic, structure or characteristic. Moreover, such phrases are not necessarily belong to the same option implementation. Additionally, when the trait, structure or response is described in connection with the option exercise, it is stated that in the framework of specialist knowledge in this area is the implementation of such a character, structure or performance in connection with other variants of realization of whether or not they are described explicitly.

[0018] In the following description and the claims can use the concept of "associated" and "connected" along with their derivatives. It should be clear that concepts are not synonymous with each other. "Connected" is used to indicate that two or more items, which may or may not be in direct physical or electrical contact with each other, work together, or interact with each other. "Connected" is used to indicate create a relationship between two or more elements that are related to each other.

[0019] Methods, shown in the figures, can be implemented using the code and data that is stored and executed on one or more electronic devices (for example, the network element and so on). Such electronic devices store and transfer (internal and/or with other electronic devices over the network) code and data, using machine-readable storage medium, such as a machine-readable storage medium (for example, magnetic disks, optical disks; the storage device on a random sample; the permanent storage; flash memory; memory with phase change) and machine-readable medium of communication (for example, electrical, optical, acoustic, or other distributed signals - such as carrier waves, infrared signals, digital signals, etc). In addition, an electronic device, as a rule, includes a group of one or more CPUs that are associated with one or more other components, such as a storage device, one or more devices input/output (for example, keyboard, touch screen and/or display) and a network connection. Linking a group of processors and other components, as a rule, is carried out by one or more tires and bridges (also referred to as the controllers of tyres). Storage device and signals that carry the network traffic, respectively, represent one or more machine-readable medium machine-readable data and communication environment. Thus, the storage device, specified electronic device, usually stores the code and/or data for performance by the group of one or more CPUs of this electronic device. Of course, one or more parts of the variants of the invention can be implemented using different combinations of software, firmware and/or hardware.

[0020] Used here is "a network element (such as a router, switch, bridge, and so on) is part of the equipment for the organization network, including hardware and software that connects with the possibility of communication other equipment in the network (for example, other network elements, computer end-station etc). Some network elements are "network elements, with many services that provide support many functions of the organization of network (for example, routing the connection in a bridge circuit, switching, aggregation level 2 and/or subscriber management) and/or provide support for multiple application services (such as data, voice and video).

[0021] Within a certain network elements can be configured many "interfaces". Used here, "interface" is the connection between the network element and one of its attached networks. The interface has information associated with it, which, as a rule, is obtained from the basic low-level protocols and routing protocols (such as IP address and mask). The interface is sometimes referred to as a line of communication. Broadcast interface is the interface that connects to the broadcasting network.

[0022] Describes a method and device for synchronization LDP-IGP for broadcast networks. In one embodiment, the invention, when you create a line of communication with the broadcasting network, the network element whose line is created, should postpone the announcement of the communication line for a broadcasting network up until LDP will not work for all neighbors in this broadcast communication lines (all broadcast neighbors). For example, the network element determines whether the communication line only way to broadcasting network. If this line is the only way to broadcasting network, the interface corresponding to the relevant line is marked as the target interface. When a network element is ready to renew its Declaration of state of the communication line (LSA) using the lines of communication to broadcast the network, it will postpone adding this line in your LSA, if appropriate interface is not terminal interface and LDP is not working for all neighbors on this interface. After LDP becomes a work for all neighbors on this interface (for example, LDP becomes synchronized with the IGP), communication line will be added to the LSA and it will be transferred to the broadcasting network.

[0023] Used here the concept of the "Declaration of the state of the communication line" and "LSA" are Protocol independent. For example, if the IGP is a Protocol for Priority Open Shortest Paths (OSPF), the Declaration of the state of the communication line can be LSA Router (Router-LSA). If the IGP is a communications Protocol intermediate system - intermediate system (is-is), then the Declaration of the state of the communication line can be switched PDU State of the Communication Line.

[0024] In one embodiment, if the IGP is a Protocol for Priority Open Shortest Paths (OSPF), LSA Router is not updated when using the Line Connection Type 2 (lines of communication with the transit network) for subnet up until LDP will not work for all network elements in a given subnet.

[0025] In one embodiment, if the IGP is a communications Protocol intermediate system - intermediate system (is-is), the PDU State of the Communication Line is not updated using the TLV, Achievable for IS (or Extended TLV, Achievable for IS)to a broadcasting network up until LDP will not work for all network elements.

[0026] Figure 1 shows the approximate broadcast network according to one embodiment of the invention. Network 100 includes network elements 105, 110, 130, 140, 145, 150, 155, 160, 165 and 170, and broadcast pseudouser 120. Each of the network elements 110, 130, 140, 145, 150 directly linked to broadcast pseudoatom 120. It should be clear that the topology of the network is 100 approximate, and in the variants of the invention can be used in other topologies. For example, some versions of the implementation of the broadcast pseudouser not used.

[0027] In one embodiment, the network elements 105, 160, 165, and 170 are the network elements of the supplier, and the network is 100 network with Multi-Protocol Switching Labels (MPLS) with applications in a Virtual Private Network (VPN). As one example, the network element 105 may be the path of the LSP on the LDP to network elements 160, 155, 170 and/or 165. It should be clear that the network 100 can be created in other ways at LDP LSP.

[0028] Each of the network elements 110, 130, 140, 145, 150 announces their respective costs interface broadcast pseudouser 120. To clarify, the network element 110 is to declare the cost of 1 to broadcast interface 114, network element 130 will announce the cost of 1 to broadcast interface, 132, network element 140 will announce the cost of 1 to broadcast interface 142, network element 145 will announce the cost of 1 to broadcast interface 146, and network element 150 will declare the cost of 1 to broadcast interface 152. In addition, as an example, every other line communication network 100 has a cost equal to 1, except for lines of communication between network element 110 and network element 165, which has a cost of 10. Broadcast pseudouser 120 also announces its interfaces to its neighbors (for example, through interfaces 122, 124, 126 and 127) with a cost of zero. It should be clear that the interfaces as shown in Figure 1, are approximate, and other interfaces are not illustrated, in order not to complicate the understanding of the invention.

[0030] In addition, as a result of using the mechanism described in RFC 5443 "Synchronization LDP and IGP" for broadcast networks, traffic can be ignored (consistently sbrasyvanie) network element from the fact that each broadcast network element declares a maximum costs. For example, using the network topology in Figure 1 and the same costs of communication lines, as in the previous example, the network element 105 passes the VPN traffic to the network element 160 before the interface 132 becomes operational on the network element 130, and at LDP LSP that carries the VPN traffic, will have the following way: from the network element 105 to network element 110 to network element 140 to network item 155 to a network element 160 (this is the only possible path topology). Once the interface 132 becomes operational, it should be clear that there will be additional possible LSP for LDP from the network element 105 to the network item 160, once the data exchange between peers on LDP on this way (from the network element 105 to network element 110 to network element 130 to the network item 160). Once created, this LSP for LDP will be preferable to the previous LSP, as it will have a lower cost (in this example, 3 against 4). However, as each line of communication broadcasting network will be declared as having a maximum cost, the route through the network item 130 will have lower costs than the route via the network elements and 155 140. As a result, the network element 110 will switch its next jump to a network element with 150 network element 140 to network element 130 before will be created at LDP LSP through the network item 130. Subsequently, the network element 110 try and fail during transmission VPN traffic to the network element 160 through the network item 130 as long as there is no LSP on LDP (for example, network element 110 will not have the correct tags to handle VPN traffic). Thus, the VPN traffic will be ignored network element 110. The volume of traffic loss in this case, at least, depends on the time required to LSP on the LDP was working. Despite the fact that the topology in Figure 1 is very simple, it should be clear that in certain topologies required time may take up to several minutes (which may affect the safety metrics class bearing).

[0031] When another interpretation of RFC 5443 "Synchronization LDP and IGP", when applied to the broadcast networks, when on a broadcast network is detected a new network element, only the network element provides the maximum costs to the broadcasting network and other network elements convey their normal costs. However, this interpretation also allows the option of ignoring traffic. It should be clear that, despite the fact that the network element 130 announces to broadcasting network maximum costs, it only affects the traffic network element 130 and will not affect the traffic accept network element 130. Thus, from the point of view of network element 110, line of communication between network element 110 and network element 130 will have a cost equal to 1. Using the same example as above, and as IGP will be faster than the LDP, network element 110 try and fail during transmission VPN traffic to the network through a network element element 130 until, until you create this LSP at LDP. Thus, similar to the example above, the VPN traffic will be ignored on the network element 110.

[0032] In contrast, as will be described later, variants the invention allows synchronization LDP-IGP in broadcasting networks without causing sub-optimal deviation traffic or ignoring traffic.

[0033] Figure 2 is a block diagram sample network element configured to synchronize LDP-IGP for broadcast networks in accordance with one of the embodiment of the invention. Although Figure 2 illustrates a network element 130 should be clear that one or more of the network elements in the network 100 may include similar features. As illustrated in Figure 2, the network element 130 fee includes 210 control associated with the card 260 data. Fee 210 management includes interface 230 command-line module 220 IGP module 235 state management interfaces, the module 240 LDP and the module 250 manage tags. Module 220 IGP includes module 280 determine the target part and SPF and the module 285 LSA synchronization LDP-IGP. Module 220 IGP manages table 222 adjacency with neighbors, base 224 data state lines, local RIB (base routing information) 226 on the IGP and the local structure 228 interface IGP.

[0034] Module 220 IGP may receive the configuration settings synchronization LDP-IGP for broadcast network interface 230 command line. For example, a network administrator can use the interface 230 command line to configure synchronization LDP-IGP for broadcast on the network element 130 (for example whether to allow the synchronization LDP-IGP for broadcast networks, one or more interfaces to monitor synchronization LDP-IGP for broadcast networks, and so on). In another embodiment, in the network element 130 for each broadcast interface is installed, the synchronization engine LDP-IGP for broadcast networks.

[0035] Module 235 state management interfaces drive interfaces network element 130, including interfaces 132 and 134. For example, a module 235 state management interfaces detects when the interface is operational. Module 235 state management interfaces associated with a module 220 IGP. Module 220 IGP registers these broadcast interfaces (for example, interfaces specified during configuration) using module 235 state management interfaces. Module 235 state management interfaces notifies the module 220 IGP at the moment of changing the status of one of these registered interfaces (for example, that a broadcast interface is working, broadcast interface has lost working capacity and so on). Then the module 220 IGP can update the local structure 228 interface IGP using these interfaces.

[0036] Module 220 IGP creates and maintains connectivity with neighbors with other network elements in a network of 100. For example, a module 220 IGP transmits and receives welcome packs from other network elements in the network 100. Of these welcome package module IGP creates and stores the table 222 adjacency with neighbors.

[0037] Module 220 IGP also transmits and receives information of the state of the communication lines (usually in the form of declarations about the state of the communication line (LSA)) for designing a network topology 100. Of the LSA, which it receives and transmits module 220 IGP creates and maintains a database 224 data state lines (so the base 224 data state lines is a representation of the network topology network 100). Figure 5B shows the approximate base 224 data state lines according to one embodiment of the invention. As illustrated in Figure 5B, base 224 data state lines includes field 530 From field To 540, and field 550 Line.

[0038] Module 220 IGP also includes a module 280 detection of the target part and SPF to determine the optimum route to destinations base 224 data state lines (thus, the SPF algorithm is applied to the information base 224 data state lines). The final routes are added to the local RIB 226 IGP, which are then programmed into one or more FIB (databases of information about the shipment) Board 260 data. For example, routes in RIB 260 IGP programmed in one or more processing modules packages with one or more line cards in the network element 130.

[0039] In addition to identifying the best ways to destinations in the database 224 data state lines of communication module 280 detection of the target part and SPF determines whether the interfaces target broadcast interfaces. Target broadcast interface is the interface to the broadcasting network, which is the only way to broadcasting network. In other words, if except in connection with broadcasting network via a broadcast interface does not exist alternative ways to broadcasting network, the broadcast interface is the terminal interface. For example, referring to Figure 1, the interface 132 is not a terminal interface, as there is an alternative path in IGP to broadcast pseudouser 120 (from the network element 130 to a network element 160 to network item 155 to a network element 140 to broadcast pseudouser 120). Interface 146 is the terminal interface, as there is no alternative ways IGP to broadcast pseudouser 120. If the interface is a terminal interface, this interface is set property tip in the local structure of 228 interface IGP.

[0040] In one embodiment, the invention, the module 280 detection of the target part and SPF determines in respect of termination of the broadcast interface by adding stage of the SPF calculation that adds network prefix to RIB 226 IGP to include additional check whether the prefix interface that has lost working capacity (for example, if the prefix corresponds to the interface, incapable of working, the prefix will be seen elsewhere, and the interface is not terminal) or is the target network, beyond which further traffic cannot go. Of course, you can use other methods to determine whether there are alternative ways to network broadcasts.

[0041] As described earlier, the module 220 IGP transmits and receives LSA for designing a network topology 100. Module 220 IGP includes module 285 LSA synchronization LDP-IGP, which eliminates the communication line of the LSA, whose respective broadcast interfaces are not terminal interfaces up until LDP will not work for all neighbors on this interface. In other words, in relation to a broadcast interface, if there is an alternative way to broadcasting network, the module 285 LSA synchronization LDP-IGP will void the line corresponding to the broadcast interface from its LSA as long as there will not be synchronized LDP and IGP (for example, when the LDP will work for all neighbors on this broadcast interface). In one embodiment, if the LDP is not fully work for a broadcast interface, the local structure 228 interface IGP flag is set to ban lines of communication in the LSA.

[0042] Figure 5A shows the approximate local structure 228 interface IGP according to one embodiment of the invention. As illustrated in Figure 5A, local structure 228 interface IGP includes field 510 interface that identifies the local interface IGP box 515 properties of terminal interface, which indicates whether the interface terminal interface, and the flag 520 ban lines of communication in the LSA, which indicates whether the interface to be prohibited in the LSA.

[0043] Module 240 LDP agree labels with other network nodes in a network of 100. In one embodiment, the module 240 LDP determines when the LDP is fully working for a particular broadcast interface, and notifies the module 220 IGP that the LDP is fully working for this interface. Then the module 220 IGP can remove the flag 520 ban lines of communication in the LSA, if it was installed (if the interface was not terminal interface), and to declare the communication line other network elements. Module 240 LDP is also associated with the module 250 control marks, which creates and stores the structure(s) 255 LSP, which, among other things, creates and manages labels for LSPs. Labels are programmed for one or more databases of information about the shipment labels (LFIB) Board 260 data. For example, a label stored in the structure(s) 255 LSP, programmed for one or more of the modules packet processing one or more line cards in the network element 130.

[0044] it Should be clear that in some variants of implementation target interfaces are not excluded from the LSA, as they are the only route to a broadcasting network. Thus, as there are no other ways for traffic flow, traffic for any LSP is dispatched after the LDP will work.

[0045] Figure 3 is a block diagram that illustrates the approximate synchronization operations LDP-IGP for broadcast networks in accordance with one of the embodiment of the invention. Operations on the Figure 3 will be described with reference to indicative options for implementation at Figures 1 and 2. However, it should be clear that the operations on the Figure 3 can run variants of the invention, other than those that are considered with reference to Figures 1 and 2, and options for implementation, considered with reference to Figures 1 and 2, can perform operations other than those that are considered with reference to Figure 3.

[0046] During surgery 310 in the broadcast interface is detected event readiness neighbor. For example, a module 220 IGP can detect an event readiness neighbor by the acceptance of the message welcome package from the network element interface 132, which is not presented in the table 222 adjacency with neighbors, where a welcome package includes the ID of the network item 130, and exchanged their information LSA and sync (it should be clear that this information Declaration of the state of the communication line does not include an interface to a nonbroadcasting network, i.e. a broadcast interface 132). Processing from the block of 310 goes to the unit 320, where module 220 IGP determines whether the first neighbor neighbor on the interface. For example, if the table 222 adjacency with neighbors does not include any entry for the interface in the table 222 adjacency with neighbors, then a new neighbour is the first neighbor on the interface.

[0047] If the neighbor is the first neighbor on the interface, then processing proceeds to block 335, otherwise processing proceeds to block 350. In block 315 interface broadcasting network is detected as done. For example, a module 235 state management interfaces finds that the interface is 132 work. Processing proceeds from block 315 to block 335, where module 220 IGP determines whether the detected interface 132 terminal interface to broadcast pseudouser 120. For example, a module 220 IGP accesses the local structure 228 interface IGP to check the properties of the end interface 132. With reference to Figure 1, the interface 132 is not terminal interface (and in this case the property tip will show it)because there is an alternative way to broadcast pseudouser 120. If the interface is not the target, processing moves to block 340, otherwise processing proceeds to block 350.

[0048] block 340 module 220 IGP determines whether completed for the interface 132 synchronization LDP-IGP. For example, a module 220 IGP accesses the local structure 228 interface IGP to check the state of the flag of the ban lines of communication in the LSA for an interface, 132. Flag to indicate whether the module 220 IGP to consider the LDP and IGP as synchronized (for example, if the flag is set, then the module 220 IGP considers LDP and IGP as not synchronized, and if the checkbox is cleared, then the module 220 IGP considers LDP and IGP as synchronized). If synchronization LDP-IGP completed, processing moves to block 325; otherwise processing proceeds to block 345. In box 345, as synchronization LDP-IGP is not completed and the interface is not the target interface is set to ban lines of communication in the LSA. Processing proceeds from block 345 to block 350, where processing continues, and broadcast networks are declared only those lines of communication, which are not forbidden (as indicated by a flag ban lines LSA).

[0049] for Example, the module 220 IGP lays the transfer of the LSA, which includes broadcast interface 132 to broadcast pseudouser 120 up until LDP will not work for all neighbors interface 132. Thus, in contrast to the RFC "Synchronization LDP and IGP", which will announce the line of communication with maximum costs before LDP will work, variants the invention, the communication line is not declared until then, until the LDP will not work. By not declaring the communication line before will not be synchronized LDP and IGP, other network elements in a network of 100 can not use the line of communication, so as checking the bidirectional capabilities of the communication will fail until then, until synchronized LDP and the IGP. Thus, in contrast to the examples discussed earlier with a reference to RFC "Synchronization LDP and IGP", when using the embodiments of the invention traffic will be redirected to a non-optimal communication lines and traffic will not be ignored.

[0050] Figure 4 is a block diagram that illustrates the approximate operation when the sync LDP-IGP completed, according to one embodiment of the invention. Operations on the Figure 4 will be described with reference to indicative options for implementation at Figures 1 and 2. However, it should be clear that the operations on the Figure 4 can be met by the variants of the invention, other than those that are considered with reference to Figures 1 and 2, and options for implementation, considered with reference to Figures 1 and 2, can perform operations other than those that are considered with reference to the Figure 4.

[0051] block 410, in response to the module exit 240 LDP from the synchronization process LDP-IGP for interface module 240 LDP module sends 220 IGP message notification synchronization LDP-IGP. In one embodiment, the synchronization process LDP-IGP will be finished at the end of configurable timer that allows the creation of a session LDP. For example, based on empirical data, the network administrator can configure the timer, which provides for the worst case (or best guess) time, which can take the process of transition LDP in working condition at all neighbors interface. The configuration value for the timer can be enabled in the configuration settings synchronization LDP-IGP for broadcast networks, the module accepts 220 IGP.

[0052] In another embodiment, the network element 130 can implement a mechanism LDP End-LIB (End-of-LIB), as stated in the project document IETF "LDP End-of-LIB: draft-ietf-mpls-end-of-lib-03.txt”January, 2009, to determine when the output from the synchronization process LDP-IGP. For example, when LDP End-LIB, each peer LDP (neighbor) may signal the end of their ad marks, accompanying a new session. After taking all of termination signals from each peer LDP LDP will work for all neighbors and exits the synchronization process LDP-IGP.

[0053] Treatment of proceeds from the block 410 to block 415, where module 220 IGP determines whether the interface flag 520 ban lines of communication in the LSA. If the flag is not set, then processing proceeds to block 420, which is taking alternative actions (for example, requires no treatment). If the flag is set, then processing proceeds to block 425, where module 220 IGP unsets the flag 520 ban lines of communication in the LSA for the interface. Processing proceeds from block 425 to block 430.

[0054] In one embodiment, the invention, the interface will be removed from the database 224 data state lines of communication, if the flag ban lines of communication in the LSA installed. Thus, in the block 430 module 220 IGP updates the database 224 data state lines of communication via interface. Processing proceeds from block 430 to the unit 435, where module 220 IGP performs the SPF algorithm over information database state lines for possible upgrade local RIB 226 IGP using a more profitable route. Then processing proceeds to block 440, where the payment data (for example, FIB 270) is programmed using the updated information about the route. Then processing proceeds to block 445, where module 220 IGP includes an interface in your LSA, and then processing proceeds to block 450, where module 220 IGP passes LSA, which includes the interface, its neighbors.

[0056] block 610 module 285 LSA synchronization LDP-IGP starts the update process the announcement of the state of the communication line. The process of updating the announcement of the state of the communication line will include an attempt to add a broadcast interface to a broadcast network (e.g., to broadcast pseudouser 120). Processing proceeds from block 610 to the unit 620, where module 285 LSA synchronization LDP-IGP determines whether the interface flag ban lines of communication in the LSA. If the flag is not set, then processing proceeds to block 630, where interface is included in the Declaration of the state of the communication line. If IGP is OSPF, LSA Router is updated by using the Line connection Type 2 (communication lines to transport networks) for the subnet. If IGP is ISIS, the PDU Status line is updated using the TLV IS Achievable for (or Extended TLV, Achievable for IS). If the flag is set, then processing proceeds to block 640 where this interface is excluded from the Declaration of the state of the communication line.

[0057] unlike RFC 5443 "Synchronization LDP and IGP" described here, the synchronization mechanism LDP-IGP for the broadcast networks are not required to be implemented on each of the network elements 110, 130, 140, 145, 150 network 100. In some variants of implementation, at a minimum, only the network element that is added to the broadcasting network, implements described here synchronization mechanism LDP-IGP for broadcast networks. Thus, described here synchronization mechanism LDP-IGP for broadcast networks can be implemented gradually without any options, providing backward compatibility.

[0058] moreover, unlike RFC 5443 "Synchronization LDP and IGP", which requires each network element that declares the maximum cost for a broadcasting network, returned back to the Declaration of their normal costs after you become a working information exchange with peers on LDP between network elements on a broadcast network (which is a difficult process that requires coordination between all network elements), variants the invention does not require any action other network elements, different from the network element, whose communication line to a broadcast network is operational.

[0059] Figure 7 shows a sample network element used in some embodiments of the invention. As illustrated in Figure 7, the network element 130 includes maps 715 and 720 control (for example, one card management is active and the other is a backup), card 725A-725N resources and linear maps 730A-730N. It should be clear that the architecture of the network item 130, illustrated in Figure 7, is indicative and is an excellent combinations of cards can be used in other embodiments of the invention.

[0060] Each of the illustrated in Figure 7 card includes one or more processors and one or more storage devices. For example, linear maps 730A-730B usually include one or more of the modules packet processing for handling packages, including the shipment and/or packet switched at high speeds, and includes one or more storage devices to store database information on the shipment (sometimes called a routing table) and a database of information about the shipment labels. Card 715 and 720 management also include one or more processors to perform signaling, routing (including the establishment and/or management of the routing tables), the connection setup, configuration, session, etc. For example, among other things, the map 715 management takes the instructions stored in the memory device for realization of the module 220 IGP and module 240 LDP.

[0061] Despite the block diagram on the figures show a particular sequence of operations of a certain variant of the invention, it should be clear that such an order is estimated (for example, alternative implementation can perform in a different order, to combine some operations, to perform tasks together and so on).

[0062] Although the invention was described on the basis of some embodiments, a specialist in this field will be aware that the invention is not limited to the described variants of implementation and can be applied in practice with modifications and changes, not far from the nature and volume of the supplied the claims. Thus, the description should be viewed as illustrative, rather than restrictive.

2. The method according to claim 1, additionally contains a stage, where in response to a determination that the LDP is a work for all neighbors on this broadcast interface, include this broadcast interface in the LSA and pass this LSA on a broadcast network.

3. The method according to claim 1, further comprising stages where: set a flag ban lines of communication in the LSA for broadcast interface up until LDP will not work for all neighbors on this broadcast interface; and thus postponing the inclusion of a broadcast interface LSA includes checking flag ban lines of communication in the LSA when upgrading LSA to determine whether to add a broadcast interface upgradeable LSA.

4. The method according to claim 1, further comprising stages, on which lay the updating of the database of the state communication lines (LSDB) network element using a broadcast interface up until LDP will not work for all neighbors in a broadcast interface.

5. The method according to claim 1, wherein the definition of what there is at least one alternative way to achieve broadcasting network, includes the following stage at which: during the performance of the algorithm of priority shortest paths (SPF), determine that the network prefix associated with a broadcast interface that belongs to the interface, incapable of working.

6. The method according to claim 1 in which the LDP is defined as work for all neighbors once expired the synchronization timer LDP-IGP.

7. The method according to claim 1, wherein the network element is that implements the Protocol Priority Open Shortest Paths (OSPF), and postponing the inclusion of a broadcast interface LSA includes the stage at which lay update LSA Router by using the Line Type 2 for a broadcasting network up until LDP will not work for all neighbors on this broadcast interface.

8. The method according to claim 1, wherein the network element is that implements the Protocol intermediate system - intermediate system (is-is), and postponing the inclusion of a broadcast interface LSA includes the stage at which lay update PDU State of the Communication Line using the TLV, achievable for IS for a broadcast network up until LDP will not work for all neighbors on this broadcast interface.

9. The method according to claim 1 in which the traffic is traffic a Virtual Private Network (VPN).

10. The network element to perform synchronization LDP-IGP (allocation Protocol label Protocol interior gateway) on a broadcast network that contains: one or more processors for execution of instructions; and one or more storage devices, CPU-related, with one or more mass storage devices have the instructions in the performance prescribe one or more processors to perform operations, including: detection of the fact that the broadcast network interface element was working, with a broadcast interface is used to transfer traffic on the way switched labels (LSP) between network element and broadcasting network; the definition of what there is at least one alternative way to achieve broadcasting network, except through a broadcast interface; and postponing the inclusion of a broadcast interface in the Declaration of the state of the communication line (LSA) as long as the allocation Protocol label LDP will not work for all neighbors on this broadcast interface.

11. Network element in paragraph 10, in which one or more storage devices optional have the instructions in the performance prescribe one or more processors to perform the following operations: in response to a determination that the LDP is a work for all neighbors on this broadcast interface, enable this broadcast interface in the LSA and transfer the LSA on a broadcast network.

12. Network element in paragraph 10, in which one or more storage devices optional have the instructions in the performance prescribe one or more the processor to perform the following operations: the flag of the ban lines of communication in the LSA for broadcast interface up until LDP will not work for all neighbors on this broadcast interface; and thus postponing the inclusion of a broadcast interface LSA includes checking flag ban lines of communication in the LSA when upgrading LSA to determine whether to add a broadcast interface upgradeable LSA.

13. Network element in paragraph 10, in which one or more storage devices optional have the instructions in the performance prescribe one or more processors to perform the following operations: to delay the update of the database state lines (LSDB) network element using a broadcast interface up until LDP will not work for all neighbors in a broadcast interface.

14. Network element in paragraph 10, in which the definition of what there is at least one alternative way to achieve broadcasting network, includes the following: during the performance of the algorithm of priority shortest paths (SPF), determining that the network prefix associated with a broadcast interface that belongs to the target network.

15. Network element in paragraph 10, in which the LDP is defined as work for all neighbors once expired the synchronization timer LDP-IGP.

16. Network element in paragraph 10, in which the network element is that implements the Protocol Priority Open Shortest Paths (OSPF), and postponing the inclusion of a broadcast interface LSA involves deferring update LSA Router by using the Line Type 2 for a broadcasting network up until LDP will not work for all neighbors on this broadcast interface.

17. Network element in paragraph 10, in which the network element is that implements the Protocol intermediate system - intermediate system (is-is), and postponing the inclusion of a broadcast interface LSA involves deferring update PDU State of the Communication line using the TLV, achievable for IS for a broadcast network up until LDP will not work for all neighbors on this broadcast interface.

18. The network element to perform synchronization allocation Protocol label (LDP) Protocol interior gateway (IGP) for broadcast networks, contains: module IGP to perform the following: determine whether broadcast interfaces network element terminal interfaces to broadcast networks, thus terminal interface is the interface to the broadcasting network and there are no other ways to this broadcast network, postponing the inclusion of those broadcast interfaces, which are not end-to-end interfaces in the announcement of the state of the communication line up until the LDP will not work for all neighbors according to the broadcast interfaces; and module LDP associated with the module IGP, this module LDP is made for the exchange of bindings labels with neighbors network element for broadcast interfaces.

19. Network element on p in which the module IGP addition made in order to delay the update of the database state lines of communication with those broadcast interfaces, which are not end-to-end interfaces, up until the LDP will not work for all neighbors according to the broadcast interfaces.

20. Network element on p in which the module IGP additionally performed for the execution of the algorithm of priority shortest paths (SPF), which includes the determination of whether the broadcast interfaces terminal interfaces.

21. Network element on p in which the module IGP additionally made to include those broadcast interfaces that are the target interfaces in the announcement of the state of the communication line, regardless of whether it is in working condition LDP for all neighbors according to the broadcast interfaces.