METHOD FOR EQUIPMENT SELECTION IN GENERALIZED MULTIPROTOCOL LABEL SWITCHING

Abstract

A method of synchronizing state of a Label Switched Path (LSP) of a Generalized Multiprotocol Label Switching (GMPLS) based optical communication network with that of a data plane of the network is disclosed. The method includes: receiving, at a network device, Resource ReserVation Protocol (RSVP) path objects that include at least one private object, wherein the at least one private object carries information that enables control plane of the network to synchronize at least one node downstream of the LSP; and synchronizing, using the network device, the state of the LSP with state of the data plane based on the at least one private object. The at least one private object can include one or more specific structures that enable the at least one node to uniquely identify and program equipment operatively connected with the at least one node.

Claims

1. A method of synchronizing state of a Label Switched Path (LSP) of a Generalized Multiprotocol Label Switching (GMPLS) based optical communication network with that of a data plane of the network, said method comprising: receiving, at a network device, Resource ReserVation Protocol (RSVP) path objects that comprise at least one private object, wherein the at least one private object carries information that enables control plane of the network to synchronize at least one node downstream of said LSP; and synchronizing, using the network device, said state of said LSP with state of said data plane based on said at least one private object.

2. The method as claimed in claim 1, wherein said at least one private object comprises one or more specific structures that enable said at least one node to uniquely identify and program equipment operatively connected with said at least one node, and wherein said at least one private object is of Type-Length-Value (TLV) format, and carries information pertaining to a restoration LSP or a protection LSP.

3. The method of claim 1, wherein said at least one private object piggybacks on said RSVP path objects to carry said information from one node to another of said network.

4. The method of claim 1, wherein said method facilitates a mechanism to identify hardware for provisioning of restoration paths in a tunnel following 1+1+R protection scheme.

5. The method of claim 1, wherein said control plane chooses said LSP's head node as master and enforces configuration and card selected to said at least one node.

6. The method of claim 1, wherein the method is applicable to all network topologies.

7. The method of claim 1, wherein the method enables implementation of ASON (Automatically Switched Optical Network) to create more than two paths to support 1+1+R protection during span of multiple cuts in optical fibre used in the network.

8. The method of claim 1, wherein said method enables said RSVP path objects to link current LSP with all associated LSPs in said network in order to find correct/redundant hardware to be programmed.

9. The method of claim 1, wherein said method enables Rx path of various nodes in said LSP to be kept in sync so as to have minimum disruption time.

10. A network device configured in a Generalized Multiprotocol Label Switching (GMPLS) based optical communication network having a Label Switched Path (LSP), said network device comprising one or more processors coupled with a memory, the memory storing instructions executable by the one or more processors to: receive, at the network device, Resource ReserVation Protocol (RSVP) path objects that comprise at least one private object, wherein the at least one private object carries information that enables control plane of the network to synchronize at least one node downstream of said LSP; and synchronize, using the network device, state of said LSP with data plane of said network based on said at least one private object.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:

[0034] FIGS. 1A to 1C elaborate upon present RSVP protocol based optical communication networks (Prior Art).

[0035] FIG. 2 illustrates an implementation of method proposed in accordance with an exemplary embodiment of the present disclosure.

[0036] FIG. 3 illustrates method proposed in accordance with an exemplary embodiment of the present disclosure.

[0037] FIG. 4 elaborates upon structure of a private object of a TLV format in accordance with an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

[0038] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0039] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.

[0040] Embodiments of the present invention include various steps, which will be described below. The steps may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, steps may be performed by a combination of hardware, software, and firmware and/or by human operators.

[0041] Various methods described herein may be practiced by combining one or more machine-readable storage media containing the code according to the present invention with appropriate standard computer hardware to execute the code contained therein. An apparatus for practicing various embodiments of the present invention may involve one or more computers (or one or more processors within a single computer) and storage systems containing or having network access to computer program(s) coded in accordance with various methods described herein, and the method steps of the invention could be accomplished by modules, routines, subroutines, or subparts of a computer program product.

[0042] If the specification states a component or feature may, can, could, or might be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.

[0043] As used in the description herein and throughout the claims that follow, the meaning of a, an, and the includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of in includes in and on unless the context clearly dictates otherwise.

[0044] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.

[0045] The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth in the appended claims.

[0046] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.

[0047] Embodiments of the present invention may be provided as a computer program product, which may include a machine-readable storage medium tangibly embodying thereon instructions, which may be used to program a computer (or other electronic devices) to perform a process. The term machine-readable storage medium or computer-readable storage medium includes, but is not limited to, fixed (hard) drives, magnetic tape, floppy diskettes, optical disks, compact disc read-only memories (CD-ROMs), and magneto-optical disks, semiconductor memories, such as ROMs, PROMs, random access memories (RAMs), programmable read-only memories (PROMs), erasable PROMs (EPROMs), electrically erasable PROMs (EEPROMs), flash memory, magnetic or optical cards, or other type of media/machine-readable medium suitable for storing electronic instructions (e.g., computer programming code, such as software or firmware). A machine-readable medium may include a non-transitory medium in which data can be stored and that does not include carrier waves and/or transitory electronic signals propagating wirelessly or over wired connections. Examples of a non-transitory medium may include, but are not limited to, a magnetic disk or tape, optical storage media such as compact disk (CD) or digital versatile disk (DVD), flash memory, memory or memory devices. A computer-program product may include code and/or machine-executable instructions that may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0048] Embodiments of the proposed invention may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks (e.g., a computer-program product) may be stored in a machine-readable medium. A processor(s) may perform the necessary tasks.

[0049] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the invention may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the invention will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0050] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., such as) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0051] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

[0052] The present disclosure mainly relates to optical telecom networks. In particular, it relates to a method for equipment selection in a GMPLS network.

[0053] In an aspect, present disclosure elaborate upon a method of synchronizing state of a Label Switched Path (LSP) of a Generalized Multiprotocol Label Switching (GMPLS) based optical communication network with that of a data plane of the network. The method includes: receiving, at a network device, Resource ReserVation Protocol (RSVP) path objects that comprise at least one private object, wherein the at least one private object carries information that enables control plane of the network to synchronize at least one node downstream of the LSP; and synchronizing, using the network device, the state of the LSP with state of the data plane based on the at least one private object.

[0054] In another aspect, the at least one private object can include one or more specific structures that enable the at least one node to uniquely identify and program equipment operatively connected with the at least one node, wherein the at least one private object can be of Type-Length-Value (TLV) format, and can carry information pertaining to a restoration LSP or a protection LSP.

[0055] In an aspect, the at least one private object can piggyback on the RSVP path objects to carry the information from one node to another of the network.

[0056] In another aspect, the method can facilitate a mechanism to identify hardware for provisioning of restoration paths in a tunnel following 1+1+R protection scheme.

[0057] In another aspect, the control plane can choose the LSP's head node as master and can enforce configuration and card selected to the at least one node. Equipment comprising the nodes in this context can mean, for example, optical Muxponders/transponders and other intermediate optical hardware for a node.

[0058] In yet another aspect, the method can be applicable to all network topologies.

[0059] In an aspect, the method can enable implementation of ASON (Automatically Switched Optical Network) to create more than two paths to support 1+1+R protection during span of multiple cuts in optical fibre used in the network.

[0060] In another aspect, the method can enable the RSVP path objects to link current LSP with all associated LSPs in the network in order to find correct/redundant hardware to be programmed.

[0061] In yet another aspect, the method can enable Rx path of various nodes in the LSP to be kept in sync so as to have minimum disruption time.

[0062] In an aspect present disclosure elaborates upon a network device configured in a Generalized Multiprotocol Label Switching (GMPLS) based optical communication network having a Label Switched Path (LSP). The network device includes one or more processors coupled with a memory, the memory storing instructions executable by the one or more processors to: receive, at the network device, Resource ReserVation Protocol (RSVP) path objects that comprise at least one private object, wherein the at least one private object carries information that enables control plane of the network to synchronize at least one node downstream of the LSP; and synchronize, using the network device, state of the LSP with data plane of the network based on the at least one private object.

[0063] FIGS. 1A to 1C elaborate upon present RSVP protocol based optical communication networks (Prior Art).

[0064] As illustrated in FIG. 1A, Node 1 is an ingress node from where a tunnel based on Resource Reservation ProtocolTraffic Engineering (RSVP-TE) originates. Interchangeably, this can be termed as head node of the RSVP-TE tunnel. Node 2 is the egress node where the RSVP-TE tunnel terminates, interchangeably termed as tail node of RSVP-TE tunnel.

[0065] A and B indicated are two redundant optical muxponder/transponder cards to be programmed at ingress node. Programming involves assignment of wavelength and direction to the each card (A & B). Likewise, A and B are two redundant optical muxponder/transponder cards to be programmed at egress node. Programming involves assignment of wavelength and direction to the each card (A & B).

[0066] For communication to proceed successfully, A and A must be programmed for wavelength and coherent direction in-order to run traffic. Likewise, B and B must be programmed for wavelength and coherent direction in-order to run traffic.

[0067] In case of DWDM (Dense Wavelength Division Multiplexing) mesh networks there can be more two paths in case of 1+1+R protection scenario.

[0068] FIG. 1A illustrates a successful/desired configuration wherein Node 1 can successfully transfer data to Node 2.

[0069] FIG. 1B illustrates situation in case a better path is found that needs to be programmed, or in case of any deterioration in existing paths/nodes such as reboot of ingress Node 1 or egress Node 2, or a fault between links.

[0070] In such a case a new restoration lambda (lambda indicating a new path/tunnel that can be enabled by optical switching for routing of information) needs to be programmed. Lambda 3 is programmed at A on ingress node but on the egress node there is no mechanism provided in RSVP to find out if this Lambda 3 tunnel needs to be programmed on A or B in case none of the tunnels are previously programmed. As shown, Lambda 3 tunnel may get programmed for B where A continues to be on Lambda 1. As can be appreciated, this may lead to error conditions on the egress node 2. As shown in FIG. 1B, Lambda 1 can have a direction d1, Lambda 2 can have a direction d2, and Lambda 3 can have a direction d3.

[0071] Further, as illustrated in FIG. 1C, in case B on egress node 2 is rebooted and had Lambda 3 configured on it, by the time it boots up, Lambda 2 may get configured on B.

[0072] Now when the RSVP tunnel between B and B reprogramming starts there is no way for this tunnel to locate B on the egress node unless it pairs information about all related tunnels which is not provided in RSVP-TE protocol, as it has information of only working and protection.

[0073] FIG. 2 illustrates an implementation of method proposed in accordance with an exemplary embodiment of the present disclosure.

[0074] Method proposed enables taking advantage of loose coupling between Hardware location and the direction it is catering in order to make for an automatically configurable system. Implementation of ASON (Automatically Switched Optical Network)/GMPLS in method proposed can enable creating more than two paths to support the 1+1+R protection during the span of multiple cuts in optical fibre used in the network.

[0075] In an aspect, main objective of method proposed is synchronize the state of a label switched path (LSP) in a network with that of data plane of the network, and to facilitate a mechanism to identify the hardware for provisioning of restoration paths in tunnels following 1+1+R protection scheme.

[0076] In another aspect, the method proposed follows the principle of RSVP objects containing the TLV (Type-Length-Value) objects that carry information along the path of LSP creation, thereby allowing control plane of the network to synchronize one/more nodes along the downstream path.

[0077] In yet another aspect, method proposed makes use of Private Object in TLV format. The private object is carried by/piggybacked upon an RSVP path object. In this manner, information is carried from one node to another.

[0078] In an aspect, the control plane can choose LSP head as the master and enforce the configuration and card selected at Head node to all nodes along the path of LSP.

[0079] As illustrated in FIG. 2, a network can have various nodes shown as A, B, C and D. Of these, nodes A, B and C can be connected via a label switched path (LSP) shown as 202. Node A can be the head node, while node D can be the tail node. Each node can provide information to a corresponding private object 204 that can in turn be contained/carried/piggybacked over corresponding RSVP path object 206. The information can contain the specific structure that enables the nodes to uniquely identify a network equipment (such as of another node) and program it. In this manner, each private object can contain the specific structure that enables the nodes to uniquely identify various network equipment and program them.

[0080] For instance, information regarding cards/equipment pertaining to head end node A can be carried in private object 204a that can in turn piggyback on RSVP path object 206a. Similarly information regarding cards/equipment pertaining to intermediate node B can be carried in private object 204b that can in turn piggyback on RSVP path object 206b.

[0081] At any node needed (as shown at 210), private object(s) present in corresponding RSVP Path object can be decoded to get necessary information. For instance, as shown for node D, private object 204d piggybacking on RSVP path object 206c can be decoded to get necessary information to identify and program node D.

[0082] FIG. 3 illustrates method proposed in accordance with an exemplary embodiment of the present disclosure.

[0083] As shown in FIG. 3, a method of synchronizing state of a Label Switched Path (LSP) of a Generalized Multiprotocol Label Switching (GMPLS) based optical communication network with that of a data plane of the network can include, at step 302, receiving, at a network device, Resource ReserVation Protocol (RSVP) path objects that comprise at least one private object, wherein the at least one private object carries information that enables control plane corresponding to the data plane to synchronize at least one node downstream of the LSP.

[0084] The method can further include, at step 304, synchronizing, using the network device, the state of the LSP with state of the data plane based on the at least one private object.

[0085] FIG. 4 elaborates upon structure of a private object of a TLV format in accordance with an exemplary embodiment of the present disclosure.

[0086] Within data communication protocols, TLV (type-length-value or tag-length-value) is an encoding scheme/format used for optional information element in a certain protocol. The type and length are fixed in size (typically 1-4 bytes), and the value field is of variable size. These fields are used as follows: Type is a binary code, often simply alphanumeric, which indicates the kind of field that this part of the message represents; Length is the size of the value field (typically in bytes); and Value is a variable-sized series of bytes which contains data for this part of the message.

[0087] FIG. 4 illustrates a private object 402 in TLV format. As illustrated Type 404 of the private object 402 can be OXCC, while its Value 408 can include MPN Order, set<wavelength and direction>.

[0088] As used herein, and unless the context dictates otherwise, the term coupled to is intended to include both direct coupling (in which two elements that are coupled to each other or in contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms coupled to and coupled with are used synonymously. Within the context of this document terms coupled to and coupled with are also used euphemistically to mean communicatively coupled with over a network, where two or more devices are able to exchange data with each other over the network, possibly via one or more intermediary device.

[0089] Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms comprises and comprising should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

[0090] While some embodiments of the present disclosure have been illustrated and described, those are completely exemplary in nature. The disclosure is not limited to the embodiments as elaborated herein only and it would be apparent to those skilled in the art that numerous modifications besides those already described are possible without departing from the inventive concepts herein. All such modifications, changes, variations, substitutions, and equivalents are completely within the scope of the present disclosure. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims.

Advantages of the Invention

[0091] The present disclosure provides for a method that enables RSVP packets to link current LSP with all associated LSPs in a network in order to find correct/redundant hardware to be programmed.

[0092] The present disclosure provides for a method that creates a restoration LSP (Label Switched Path) in addition to working and protection LSP.

[0093] The present disclosure provides for a method that keeps Rx path of various nodes in an LSP in sync so as to have minimum service disruption time.