(19)
(11)EP 3 189 631 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
13.11.2019 Bulletin 2019/46

(21)Application number: 14758931.1

(22)Date of filing:  03.09.2014
(51)International Patent Classification (IPC): 
H04L 12/46(2006.01)
H04L 12/915(2013.01)
H04L 12/24(2006.01)
H04L 12/751(2013.01)
H04L 12/715(2013.01)
H04Q 11/00(2006.01)
(86)International application number:
PCT/EP2014/068769
(87)International publication number:
WO 2016/034226 (10.03.2016 Gazette  2016/10)

(54)

AUTO-DISCOVERY OF PACKET ISLANDS OVER GMPLS-UNI

AUTOMATISCHE ERKENNUNG VON PAKETINSELN ÜBER GMPLS-UNI

DÉCOUVERTE AUTOMATIQUE D'ÎLOTS DE PAQUETS SUR GMPLS-UNI


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME

(43)Date of publication of application:
12.07.2017 Bulletin 2017/28

(73)Proprietor: Telefonaktiebolaget LM Ericsson (publ)
164 83 Stockholm (SE)

(72)Inventors:
  • GERÖ, Balázs Peter
    H-1095 Budapest (HU)
  • CECCARELLI, Daniele
    I-16145 Genova (IT)
  • KERN, András
    H-1118 Budapest (HU)

(74)Representative: Zacco Sweden AB 
P.O. Box 5581
114 85 Stockholm
114 85 Stockholm (SE)


(56)References cited: : 
US-A1- 2007 133 406
  
  • FARREL (ED) J DRAKE JUNIPER NETWORKS N BITAR VERIZON NETWORKS G SWALLOW CISCO SYSTEMS A ET AL: "Problem Statement and Architecture for Information Exchange Between Interconnected Traffic Engineered Networks; draft-farrel-interconnected-te-info-exchan ge-06.txt", PROBLEM STATEMENT AND ARCHITECTURE FOR INFORMATION EXCHANGE BETWEEN INTERCONNECTED TRAFFIC ENGINEERED NETWORKS; DRAFT-FARREL-INTERCONNECTED-TE-INFO-EXCHAN GE-06.TXT, INTERNET ENGINEERING TASK FORCE, IETF; STANDARDWORKINGDRAFT, INTERNET SOCIETY (ISOC), 25 July 2014 (2014-07-25), pages 1-55, XP015100941, [retrieved on 2014-07-25]
  • DONG M CHEN HUAWEI TECHNOLOGIES J: "BGP Extensions for Inter-AS Traffic Engineering (TE) Link Distribution; draft-dong-idr-inter-as-te-link-distributi on-00.txt", BGP EXTENSIONS FOR INTER-AS TRAFFIC ENGINEERING (TE) LINK DISTRIBUTION; DRAFT-DONG-IDR-INTER-AS-TE-LINK-DISTRIBUTI ON-00.TXT, INTERNET ENGINEERING TASK FORCE, IETF; STANDARDWORKINGDRAFT, INTERNET SOCIETY (ISOC) 4, RUE DES FALAISES CH- 1205 GENEVA, SWI, 1 July 2014 (2014-07-01), pages 1-6, XP015099921, [retrieved on 2014-07-01]
  • GREDLER JUNIPER NETWORKS H ET AL: "North-Bound Distribution of Link-State and TE Information using BGP; draft-ietf-idr-ls-distribution-05.txt", NORTH-BOUND DISTRIBUTION OF LINK-STATE AND TE INFORMATION USING BGP; DRAFT-IETF-IDR-LS-DISTRIBUTION-05.TXT, INTERNET ENGINEERING TASK FORCE, IETF; STANDARDWORKINGDRAFT, INTERNET SOCIETY (ISOC) 4, RUE DES FALAISES CH- 1205 GENEVA, SWITZERLAND, 22 May 2014 (2014-05-22), pages 1-38, XP015099231, [retrieved on 2014-05-22]
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

Technical field



[0001] The present disclosure generally relates to the support of optical connection setup. More specifically, the present disclosure relates to a technique of supporting provision of a connection via a data communication network of an optical network between packet network islands.

Background



[0002] Currently, there are two existing solutions to connect a client layer Network Management System (NMS) to a remote packet network island which are separated by an optical network.

[0003] In a first solution, an out-of-band data communication network (DCN) is needed to let the NMS possess enough information about a remote edge node, in order to initiate the setup of an optical connection, e.g. between an edge node to which the NMS is connected and the remote edge node of the remote packet network island. In this respect, "out-of-band" may relate to the fact that the DCN might not share physical links with the optical network via which communication may be enabled. According to this solution an out-of-band data communication network is required. The out-of-band DCN requires a complete network to be maintained in parallel, at least temporarily at times when there is no optical connection between the edge node and the remote edge node.

[0004] In a second solution, the edge nodes are connected by means of an in-band DCN connection over an already established optical connection. The already established optical connection keeps the client layer NMS connected to one or more packet network islands. According to this solution only an already established optical connection can be used.

[0005] Document "Problem statement and architecture for information exchange between interconnected traffic engineered networks" (IETF, Standard working draft, ISOC, 25 July 2014, pages 1-55) refers to problem statement and architecture for the exchange of TE information between interconnected TE networks in support of end-to-end TE path establishment. The document is limited to simple TE constraints and information that determine TE reachability.

[0006] Document "BGP extensions for Inter-AS traffic engineering link distribution" (IETF, Standard working draft, ISOC. 01 July 2014, pages 1-6) refers to BGP extensions for dynamic advertisement of TE information of Inter-AS links between adjacent autonomous systems.

[0007] US 2007/0133406 A1 refers to a technique that enables traffic engineering on paths between customer edge devices across a provider network in a computer network.

[0008] Document "North-Bound distribution of Link-State and TE information using BGP" (IETF, Standard working draft, ISOC, 22 May 2014, pages 1-38)
refers to a mechanism by which links state and traffic engineering information can be collected from networks and shared with external components using the BGP routing protocol.

Summary



[0009] Accordingly, there is a need for an improved technique for supporting provision of a connection between two packet network islands.

[0010] A method of supporting provision of a connection via a data communication network, DCN, of an optical network between a first packet network island and a second packet network island is provided. The first packet network island and the second packet network island are connected with the optical network by means of a Generalized Multiprotocol Label Switching User-to-Network Interface, GMPLS UNI, respectively. The method comprising: establishing a Border Gateway Protocol-Link State, BGP-LS, connection via the DCN between a first edge node of the first packet network island and a BGP-LS node in the optical network; and establishing a BGP-LS connection via the DCN between a second edge node of the second packet network island and the BGP-LS node in the optical network. The step of establishing the BGP-LS connection via the DCN between the first edge node of the first packet network island and the BGP-LS node in the optical network comprises: configuring, in the first edge node, the Internet Protocol, IP, address of the BGP-LS node in the optical network; configuring, in the BGP-LS node in the optical network, the IP address of the GMPLS UNI in the first edge node as the IP address of the BGP-LS neighbour; establishing, by the DCN, the connection between the first edge node and the BGP-LS node in the optical network; and distributing, via the established connection between the first edge node and the second edge node, link Network Layer Reachability Information that is subject to policy configuration in the BGP-LS node in the optical network.

[0011] A BGP-LS node in an optical network for supporting provision of a connection via a data communication network, DCN, of the optical network between two packet network islands is provided. The BGP-LS node comprises: an establishing component configured to establish a Border Gateway Protocol-Link State, BGP-LS, connection via the DCN with a first edge node, wherein the first edge node is in at least one of the two packet network islands; a configuring component configured to configure the Internet Protocol, IP, address of a Generalized Multiprotocol Label Switching User-to-Network Interface, GMPLS UNI, in the first edge node as the IP address of a BGP-LS neighbour; and a connecting component configured to connect the BGP-LS node with the first edge node via a connection provided by the DCN. The BGP-LS node is adapted to receive from the first edge node link Network Layer Reachability Information, NLRIs, and further adapted to forward the link NLRIs to a second edge node, wherein distributing the link NLRIs from the first edge node to the second edge node is subject to policy configuration in the BGP-LS node in the optical network.

Brief description of the drawings



[0012] In the following, the present disclosure will further be described with reference to exemplary embodiments illustrated in the figures, in which:
Figure 1
schematically illustrates a prior art solution to provide a connection via a data communication network of an optical network between packet network islands;
Figure 2
schematically illustrates another prior art solution to provide a connection via a data communication network of an optical network between packet network islands;
Figure 3
schematically illustrates a GMPLS controlled optical network with two packet network islands;
Figure 4
schematically illustrates a method embodiment which may be performed in the network of Figure 3;
Figure 5
illustrates format of Link NLRIs in BGP-LS;
Figure 6a
is a flowchart illustrating a BGP-LS extension method in edge nodes;
Figure 6b
is a flowchart illustrating steps performed in an NMS or SDN controller;
Figure 7
schematically illustrates BGP-LS scenario with an SDN controlled optical network;
Figure 8
schematically illustrates an embodiment of an edge node; and
Figure 9
schematically illustrates an embodiment of a BGP-LS node.

Detailed description



[0013] In the following description, for purposes of explanation and not limitation, specific details are set forth, such as specific network architectures, in order to provide a thorough understanding of the present disclosure. It will be apparent to one skilled in the art that the present disclosure may be practiced in other embodiments that depart from these specific details. For example, although the present disclosure is described with reference to a general data communication network, the present disclosure may be practiced with specific data communication networks such as a Data Connection Network as specified by the ITU. Further, for example, the present disclosure is applicable to any wireless networks such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), LTE-Advanced (LTE-A) networks, or to Wireless Local Area Network (WLAN) or similar wireless networks, but also to wireline networks such as, for example, the Intranet of a company with some or many separated subsidiaries or the Internet.

[0014] Moreover, those skilled in the art will appreciate that the services, functions, steps and units explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP) or a general purpose computer, e.g., including an Advanced RISC Machine (ARM). It will also be appreciated that, while the following embodiments are primarily described in context with methods and devices, the present disclosure may also be embodied in a computer program product as well as in a system comprising a computer processor and memory coupled to the processor, wherein the memory is encoded with one or more programs that may perform the services, functions, steps and implement the components and devices disclosed herein.

[0015] Fig. 1 schematically illustrates a basic structure of a communication network 100. In the communication network 100, a Network Management System (NMS) 101 is connected to a packet network 102a. As illustrated in Figure 1, a controller CTRL 101 may be connected to the packet network 102a instead of the NMS 101. The packet network 102a and an edge node (EN) 103a form a packet network island 104a. Further, in the communication network 100, a packet network 102b and an EN 103b form a packet network island 104b. An optical network 106 with two core nodes (CNs) (CN 105a and CN 105b) is arranged between the ENs 103a, 103b. The packet network islands 104a, 104b are connected with the optical network 106 by means of a Generalized Multiprotocol Label Switching User-to-Network Interface (GMPLS UNI), respectively, namely GMPLS UNI 107a and GMPLS UNI 107b.

[0016] According to a first approach which can be realized in the communication network 100 illustrated in Figure 1, IP addresses of the GMPLS UNI 107a in EN 103b may be learnt from the optical network 106, e.g. by means of auto-configuration during provisioning of the UNI. However, the NMS 101 does not know which node is connected to the other side of the optical network 206, i.e., the side of packet network island 104b. In short, the NMS 101 does not know (the identity of the) EN 103b. In accordance with this approach, the NMS 101 requires an out-of-band data communication network (DCN) to let the NMS 101 possess enough information about EN 103b. Without such out-of-band DCN, setup of an optical connection, e.g. between EN 103a and EN 103b, cannot always be initiated. The out-of-band DCN, however, requires a complete network to be maintained in parallel, at least temporarily at times when there is no optical connection between EN 103a and EN 103b.

[0017] Figure 2 illustrates a second approach which can be realized in the communication network 100 of Figure 1. According to this second approach, EN 103a and EN 103b are connected by means of an in-band DCN connection over an already established optical connection. In this way, the NMS 101 is kept connected to the packet network islands 104a, 104b. However, the second approach requires an already established optical connection.

[0018] Figure 3 illustrates a communication network 200. In the communication network 200, a Network Management System NMS 201 according to a device embodiment is connected to a packet network island 204a. The packet network island 204a comprises a packet network and an EN according to a device embodiment which is in the following referred to as EN2. Further, in the communication network 200, a packet network island 204b comprises a packet network and an EN according to a device embodiment which is in the following referred to as EN1. An optical network 206 with two CNs is arranged between EN1 and EN2. The optical network 206 controls an Internet Protocol (IP) based data communication network (DCN) 208. The DCN may be a Data Connection Network as defined by the International Telecommunication Union (ITU). The packet network islands 204a, 204b are connected with the optical network 206 by means of a GMPLS UNI, respectively, namely GMPLS UNI 207a and GMPLS UNI 207b. In short, in Figure 3, an optical network 206 with two packet network islands 204a, 204b is shown. The packet network islands 204a and 204b may be part of one network, for example belong to the same client. The packet network island 204a and the packet network island 204b are separated by the optical network 206 controlling the IP based DCN 208. The interface between the packet network islands 204a, 204b and the optical network 206 is based on a GMPLS UNI, respectively. That is, the packet network island 204a is connected with the optical network 206 by means of GMPLS UNI 207a, while the packet network island 204b is connected with the optical network 206 by means of GMPLS UNI 207b. The optical network 206 can therefore be regarded as a GMPLS controlled optical network.

[0019] All details explained above and below with respect to the optical network with a GMPLS control plane as shown in Figure 3, by way of example, are equally applicable to an SDN controlled optical network. Such an SDN controlled optical network is shown in Figure 7 by way of example. In this case, a BGP-LS node 209-3 (which will be explained in more detail below with reference to Figure 9) may be co-located with a controller in the optical network 206. In consequence, all details set forth below with respect to Figure 3 equally apply to the SDN controlled optical network shown in Figure 7. In accordance therewith, when referring to the NMS 201 of Figure 3 in the following, it will be referred to the NMS or SDN controller 201.

[0020] Returning in general terms to Figure 3, by means of the network architecture shown in Figure 3, support of an automatic procedure may be provided for making known routing information associated with a node in a packet network island (such as packet network island 204b) to a further node located in a further packet network island (such as packet network island 204a) such that a connection establishment to the node can be initiated by the further node. The further node may be an edge node such as EN2, for example an edge router, or an NMS or SDN controller such as NMS or SDN controller 201. The node may be an edge node, for example an edge router, of the packet network island 204b, such as EN1. The edge node and the further edge node may respectively be defined as the node attached to an UNI link on the client network side corresponding to the packet network islands 204a, 204b. To this end, the involved control plane signaling may be sent "in-band"("in-band" with respect to the optical network 206) via the DCN 208 of the optical network 206. Here, "in-band" refers to the fact that the physical links used by the DCN 208 are shared between the DCN 208 and the optical network 206, and that the DCN 208 uses a dedicated resource (such as a frequency also called lambda) that is only used for the purpose of the (optical) DCN 208. The used control plane protocol is Boarder Gateway Protocol-Link State (BGP-LS).

[0021] In the following, some details regarding the above-mentioned automatic procedure are explained with respect to Figures 3 to 9.

[0022] Figure 8 schematically illustrates an embodiment of an edge node. The edge node of Figure 8 may be EN2 as mentioned above. In other words, EN2 of Figure 3 may be realized as explained with respect to the edge node of Figure 8. Likewise, the edge node of Figure 8 may be EN1 as mentioned above. In other words, EN1 of Figure 3 may be realized as explained with respect to the edge node of Figure 8.

[0023] In the following it is assumed for sake of explanation rather than limitation that the details of the edge node shown in Figure 8 are realized in EN1. In accordance with this example, EN1 comprises an establishing component 801. The establishing component 801 is configured to establish a BGP-LS connection via the DCN with a BGP-LS node in an optical network such as BGP-LS node 209-3 of Figure 3. The establishing component 801 may further comprise a configuring component 802 and a connecting component 803. The configuring component 802 is configured to configure the Internet Protocol (IP) address of the BGP-LS node in the optical network. The connecting component 803 is configured to connect EN1 with the BGP-LS node in the optical network via a connection provided by the DCN, when, in the BGP-LS node in the optical network, the IP address of the GMPLS UNI in EN1 is configured as the IP address of a BGP-LS neighbour.

[0024] EN1 may further comprise a distributing component 804 and an extending component 805. The distributing component 804 is configured to distribute, via the established BGP-LS connection, link Network Layer Reachability Information (NLRI). The extending component 805 is configured to extend the link NLRI to carry a reference to the IP address of the GMPLS UNI in EN1. It should be appreciated that other edge nodes, e.g. EN2, may have the same components as well as functions thereof as EN1.

[0025] Figure 9 schematically illustrates an embodiment of a BGP-LS node. The BGP-LS node of Figure 9 may be BGP-LS node 209-3 of Figure 3. In other words, BGP-LS node 209-3 of Figure 3 may be realized as explained with respect to the BGP-LS node of Figure 9.

[0026] For sake of explanation rather than limitation, the only example given in the following is that the BGP-LS node shown in Figure 9 establishes a connection with EN1. According to this example, the BGP-LS node of Figure 9 comprises an establishing component 901. The establishing component 901 is configured to establish a BGP-LS connection via the DCN with an edge node such as EN1. The establishing component 901 may further comprise a configuring component 902 and a connecting component 903. The configuring component 902 is configured to configure the Internet Protocol (IP) address of the GMPLS UNI in the edge node, e.g., the GMPLS UNI in EN1, as the IP address of a BGP-LS neighbour. The connecting component 903 is configured to connect the BGP-LS node in the optical network with the edge node, e.g., with EN1, via a connection provided by the DCN. It should be appreciated that the BGP-LS node can also establish BGP-LS connections with edge nodes in other packets network islands, e.g. EN2.

[0027] According to a method embodiment shown in Figure 4, EN1 establishes a BGP-LS connection to the BGP-LS node 209-3 shown in Figure 3 (step S402). This may involve some sub-steps as will be explained below for sake of explanation rather than limitation.

[0028] By providing a GMPLS UNI, e.g. GMPLS UNI 207b, EN1 in the packet network island 204b can learn the IP address to use in order to send packets to the network side functionality of the UNI (the network side of the UNI is in the following referred to as UNI-N) in the CN (the left CN in Figure 3). Vice versa, the CN implementing the UNI-N functionality can learn the IP address to use in order to send packets to the client side functionality of the UNI (the client or customer side of the UNI is in the following referred to as UNI-C), e.g., the IP address of EN1. The IP address of EN1 may be auto-assigned by the optical network 206 during the installation of the UNI. The UNI-C functionality may include IP addresses and IP connectivity dedicated to the GMPLS control plane. The DCN 208 of the optical network 206 serves to facilitate GMPLS signaling.

[0029] More specifically, the IP address of BGP-LS node 209-3 in the optical network 206 (more specifically, in the DCN 208 of the optical network 206) is configured in EN1. This configuration may include a configuration that an UNI link is used. In consequence, the IP address of the BGP-LS 209-3 is configured as reachable via the UNI link. For example, a BGP session is configured that supports BGP-LS Address Family Identifier/Subsequent Address Family Identifier (AFI/SAFI). The BGP-LS 209-3 may be configured to support BGP-LS AFI/SAFI. BGP-LS AFI/SAFI is an address family that includes the link NLRI. In the BGP-LS node 209-3 in the optical network 206, the IP address of the edge node EN1 is configured as the IP address of a BGP-LS neighbor. In this way, a bi-directional connection can be provided. The (optical) DCN 208 is configured to provide a routed or a bridged connection between EN1 and the BGP-LS node 209-3 in the optical network 206. Thus, a connection between EN1 and the BGP-LS node 209-3 can be configured and established. The exact implementation of the connection can be varied in dependence of the DCN technology used. For example, a Generic Routing Encapsulation (GRE) tunnel or one same IP connection may be used. According to the first option, in a routed DCN, a GRE tunnel may be set up between the left CN in Figure 3 and the BGP-LS node 209-3 in the optical network 206. Alternatively, according to the second option, in case the BGP-LS node 209-3 is co-located with the left CN in Figure 3, the same IP connectivity between EN1 and the left CN in Figure 3 can be used both for GMPLS UNI signaling and BGP-LS message exchange.

[0030] Independent of the exact realization, EN1 can establish a BGP-LS connection to the BGP-LS node 209-3.

[0031] After the UNI-C is configured in EN1 and a BGP-LS connection is established between EN1 and the BGP-LS node 209-3 in the optical network 206, EN1 may start sending BGP-LS packets with link information such as link Network Layer Reachability Information (NLRI). The link NLRI may include routing information which is sent via the established connection so that it may further be distributed. The information distribution can be subject to policy configuration of the BGP-LS neighbor, i.e. the information distribution can be allowed or can be forbidden.

[0032] When EN1 distributes link information such as link NLRI on a UNI control plane link (see step S602a in Figure 6a), e.g., from EN1 to the left CN in Figure 3, EN1 may indicate that the link is a UNI-C link. Thus, the link NLRI may be extended to carry a reference to the UNI-C IP address, i.e., the IP address of the GMPLS UNI in EN1. For example, EN1 may encode this reference into the protocol ID field of the link NLRI. As shown in Figure 6a, the reference may be a predefined value of the protocol ID field. In other words, the BGP-LS may set the protocol ID field to a predefined value, which can uniquely indicate that the link is a UNI-C link, e.g. 2 or 3 or any other value that could be included into the protocol ID field (see step S604a of Figure 6a). Summarizing Figure 6a, an EN such as EN1 is initiating a distribution of a BGP-LS link description with link NLRI corresponding to the UNI control plane link (step S602). The BGP-LS may set the protocol ID field to a predefined value (see step S604a).

[0033] The link NLRI may further comprise identification information of an edge node and link description information of the UNI link associated with the edge node. The identification information may be or comprise a Router ID. The link description information of the UNI link associated with the edge node may be or comprise an IP address of the UNI-C of the edge node. In accordance with the example shown in Figure 5, the Router ID is included in the local node descriptors field and the link description information is included in the link descriptors field of the link NLRI. The link descriptors field may follow the format of an IPv4, IPv6 or unnumbered interface address sub-TLV.

[0034] In addition to the connection between the EN1 and the BGP-LS node 209-3, the BGP-LS node 209-3 can further establish a BGP-LS connection to EN2 (see optional step S404 in Figure 4). The connection between EN2 and the BGP-LS node 209-3 in the optical network 206 may be configured and established similarly as the connection between EN1 and the BGP-LS node 209-3 in the optical network 206 as described above. Thus, similar procedures may be used for EN2 as for EN1. Alternatively, it is possible that the connection between EN2 and the BGP-LS node 209-3 in the optical network 206 has already been configured.

[0035] When there is an established BGP-LS connection between EN1 and the BGP-LS node 209-3 in the optical network 206 and there is a BGP-LS connection between EN2 and the BGP-LS node 209-3 in the optical network 206, BGP-LS is able to distribute BGP information from EN1 to EN2. As stated above with respect to the connection between EN1 and BGP-LS node 209-3, BGP-LS packets may comprise link information such as link Network Layer Reachability Information (NLRI). Likewise, the BGP-LS packets sent via the connection between EN2 and BGP-LS node 209-3 may comprise link information such as link Network Layer Reachability Information (NLRI).

[0036] As further stated above with respect to the connection between EN1 and BGP-LS node 209-3, routing information may be included in the link NLRI. Likewise, routing information may be included in the link NLRI sent over the connection between EN2 and BGP-LS node 209-3. The routing information may comprise identification information of EN1 (e.g., Router ID) and link description information of the UNI link associated with EN1 (IP address of the UNI-C of EN1). Further, an indication may be sent that the information is related to an UNI link. The indication may comprise or may be a reference, as explained above. For example, the identification information may be included in the local node descriptors field, the link description information may be included in the link descriptors field and the indication may correspond to a predefined value of the protocol ID field of the link NLRI of a BGP-LS message. Again, one example is illustrated in Figure 6a.

[0037] As explained with respect to the connection between EN1 and BGP-LS node 209-3, the optical network operator may define policies for distributing information over the DCN also with reference to the connection between EN2 and BGP-LS node 209-3. For example, the optical network operator may define certain policies for distributing the BGP information. Such policies may comprise restricted packet connection where signaling transfer only by means of BGP-LS is allowed. For example, distributing the BGP information, e.g., link NLRI, over the DCN 208 may be subject to policy configuration in the BGP-LS node 209-3 in the optical network 206. In consequence, in such a restricted case, the optical network provider may allow only BGP-LS packets from the packet network islands 204a, 204b on the DCN 208 of the optical network 206 to provide support for client layer auto-configuration. In this case, the optical network provider participates in BGP-LS and BGP policies to provide the optical network operator the tool to control information distribution over the optical DCN 208.

[0038] Alternatively, according to an unrestricted case, a trusted relationship between the client and the server layers may be assumed and any form of packet connectivity may be allowed. In this case, the connection via the DCN is unrestricted. For example, EN1 and EN2 are allowed to communicate over the DCN 208 of the optical network 206 directly.

[0039] In the following, it is explained with respect to Figure 6b how the NMS or SDN controller 201 may make use of the above mentioned method aspects.

[0040] The NMS or SDN controller 201 may be comprised in at least one of the packet network islands 204a and 204b. In the following it is assumed for explanation rather than limitation that the NMS or SDN controller 201 is in the packet network island 204a. In this case, the packet network island 204a may function as a client management system. In order to auto-discover EN1 and further setup a connection therewith after the packet network island 204b is newly connected with the optical network 206, a BGP-LS connection between EN2 and the BGP-LS node 209-3 in the optical network 206 may have already been established or may be established as explained in detail above.

[0041] In accordance with the example shown in Figure 6b, the NMS or SDN controller 201 receives a link NRLI regarding EN1 (see step S602b of Figure 6b). In accordance with the example of Figure 6a a predefined value of the protocol ID field of the link NLRI of a BGP-LS message is set to a specific value as explained above. The NMS or SDN controller 201 reads out the UNI IP address from the link descriptors field of the link NLRI (see step S604b of Figure 6b). Further, the NMS or SDN controller 201 reads out the Router ID from the local node descriptors field of the link NLRI (see step S606b of Figure 6b). In this way, the NMS or SDN controller 201 is able to determine if it has received a link description with a UNI-C IP address because of the reference in the link NLRI and, if positive, can bind the UNI-C IP address to the edge node having the Router ID (see step S608b in Figure 6b). In other words, upon receipt of this information, the NMS or SDN controller 201 binds the link description information (UNI-C IP address) to the identification information (Router ID). Thus, the NMS or SDN controller 201 has all data available to decide if it needs to set up an optical connection to the new edge node, i.e., EN1. In addition, the NMS or SDN controller 201 may store the binding of the IP address and the Router ID comprised in the link NRLI. Alternatively, the above-mentioned functions of the NMS or SDN controller 201 can be assumed or realized by EN2.

[0042] In one example, the further node (EN2 or NMS or SDN controller 201) may auto-learn the routing information (UNI-C IP address) given to the node (EN1) by the optical network 206 during installation of the node (EN1) upon receipt of the routing information via the BGP-LS connection. Such auto-learning procedures are known to the skilled person. The further node (EN2 or NMS or SDN controller 201) is then enabled to establish an out-of-band optical connection via the optical network. "Out-of-band" refers to the perspective of the packet network, since the packet network's service traffic uses the resource (such as a frequency called lambda) established between the node (EN1) and the further node (EN2 or NMS or SDN controller 201). Therefore, nodes already activated and nodes which activate later after the configuration of the GMPLS interface of the optical network 206 can be reached by the further node (EN2 or NMS or SDN controller 201). When the EN2 or the packet NMS or SDN auto-learns the routing information (the UNI-C IP address given to EN1 by the optical network during installation of EN1) further advantages can be achieved. Auto-learning enables the EN2 or the NMS or SDN controller 201 to recognize the identity and UNI-C IP address of EN1 when it is installed.

[0043] As has become apparent from above description of exemplary embodiments, nodes are enabled to establish an "in-band" optical connection via the optical network. There is no need to permanently maintain the DCN. Since there is no need to permanently maintain the DCN, cost reduction can be achieved by saving operating expenses (OPEX). Nodes already activated and nodes which activate later after the configuration of the GMPLS interface of the optical network can be easily reached by nodes on the other side of the optical network. In consequence, a technique is provided for setting up an optical connection between a local node and a remote node. Similarly, a technique is provided for setting up an optical connection between a local packet network island node and a remote packet network island (node).

[0044] Many advantages of the present disclosure will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the units and devices without departing from the scope of the present disclosure and/or without sacrificing all of its advantages. Since the present disclosure can be varied in many ways, it will be recognized that the present disclosure should be limited only by the scope of the following claims.


Claims

1. A method of supporting provision of a connection via a data communication network, DCN (208), of an optical network (206) between a first packet network island (204a) and a second packet network island (204b), wherein the first packet network island (204b) and the second packet network island (204a) are connected with the optical network (206) by means of a Generalized Multiprotocol Label Switching User-to-Network Interface, GMPLS UNI (207a, 207b), respectively, the method comprising:

• establishing a Border Gateway Protocol-Link State, BGP-LS, connection via the DCN (208) between a first edge node (EN1) of the first packet network island (204b) and a BGP-LS node (209-3) in the optical network (206), and

• establishing a BGP-LS connection via the DCN (208) between a second edge node (EN2) of the second packet network island (204a) and the BGP-LS node (209-3) in the optical network (206),

wherein the step of establishing the BGP-LS connection via the DCN (208) between the first edge node (EN1) of the first packet network island and the BGP-LS node (209-3) in the optical network (206) comprises:

• configuring, in the first edge node (EN1), the Internet Protocol, IP, address of the BGP-LS node (209-3) in the optical network (206);

• configuring, in the BGP-LS node (209-3) in the optical network (206), the IP address of the GMPLS UNI in the first edge node (EN1) as the IP address of the BGP-LS neighbour; and

• establishing, by the DCN (208), the connection between the first edge node (EN1) and the BGP-LS node (209-3) in the optical network (206);

characterized by distributing, via the established connection between the first edge node (EN1) and the second edge node (EN2), link Network Layer Reachability Information, NLRIs, that is subject to policy configuration in the BGP-LS node (209-3) in the optical network (206).


 
2. The method according to claim 1, wherein in case of a routed DCN (208), the connection provided by the DCN (208) is based on a Generic Routing Encapsulation, GRE, tunnel.
 
3. The method according to claim 1, wherein the BGP-LS node (209-3) is co-located with a core node or a controller in the optical network (206).
 
4. The method according to claim 1, wherein

• each link NLRI comprises router identification, ID, of one of the first and second edge nodes (EN1, EN2) in a local node descriptors field,

• the link NLRI further comprises IP address of the GMPLS UNI in the one of the first and second edge node (EN1, EN2) in a link descriptors field,

• the link NLRI is extended to carry a reference to the IP address of the GMPLS UNI in the one of the first and second edge node (EN1, EN2),

• the reference is a predetermined value in the protocol ID field of the link NLRI.


 
5. The method according to claim 4, wherein at least one of the first and second packet network islands comprises a Network Management System, NMS, or Software-Defined-Networking, SDN, controller, and wherein the NMS or SDN controller is configured to recognize the predetermined value and bind the IP address to the router ID comprised in the link NLRI and is configured to store the binding of the IP address and the router ID comprised in the link NLRI.
 
6. A computer program product comprising program code portions which, when executed on one or more computing devices, cause the one or more computing devices to perform all the steps of a method of any one of claims 1 to 5.
 
7. A BGP-LS node (209-3) in an optical network (206) for supporting provision of a connection via a data communication network, DCN (208), of the optical network (206) between two packet network islands (204a, 204b), the BGP-LS node (209-3) comprising:

• an establishing component (901) configured to establish a Border Gateway Protocol-Link State, BGP-LS, connection via the DCN (208) with a first edge node (EN1), wherein the first edge node (EN1) is in at least one of the two packet network islands,

• a configuring component (902) configured to configure the Internet Protocol, IP, address of a Generalized Multiprotocol Label Switching User-to-Network Interface, GMPLS UNI, in the first edge node (EN1) as the IP address of a BGP-LS neighbour; and

• a connecting component (903) configured to connect the BGP-LS node (209-3) with the first edge node (EN1) via a connection provided by the DCN (208),

characterized in that the BGP-LS node (209-3) is adapted to receive from the first edge node (EN1) link Network Layer Reachability Information, NLRIs, and further adapted to forward the link NLRIs to a second edge node (EN2), wherein distributing the link NLRIs from the first edge node (EN1) to the second edge node (EN2) is subject to policy configuration in the BGP-LS node (209-3) in the optical network (206).


 


Ansprüche

1. Verfahren zur Unterstützung der Bereitstellung einer Verbindung über ein Datenkommunikationsnetz, DCN, (208), eines optischen Netzwerks (206) zwischen einer ersten Paketnetzinsel (204a) und einer zweiten Paketnetzinsel (204b), wobei die erste Paketnetzinsel (204b) und die zweite Paketnetzinsel (204a) jeweils mittels einer Generalized Multiprotocol Label Switching User-to-Network Interface, GMPLS-UNI, (207a, 207b) mit dem optischen Netzwerk (206) verbunden sind, das Verfahren umfassend:

• Herstellen einer Border Gateway Protocol-Link State-Verbindung, BGP-LS-Verbindung, über das DCN (208) zwischen einem ersten Randknoten (EN1) der ersten Paketnetzinsel (204b) und einem BGP-LS-Knoten (209-3) in dem optischen Netzwerk (206), und

• Herstellen einer BGP-LS-Verbindung über das DCN (208) zwischen einem zweiten Randknoten (EN2) der zweiten Paketnetzinsel (204a) und dem BGP-LS-Knoten (209-3) in dem optischen Netzwerk (206), wobei der Schritt des Herstellens der BGP-LS-Verbindung über das DCN (208) zwischen dem ersten Randknoten (EN1) der ersten Paketnetzinsel und dem BGP-LS-Knoten (209-3) in dem optischen Netzwerk (206) umfasst:

• Konfigurieren, in dem ersten Randknoten (EN1), der Internetprotokolladresse, IP-Adresse, des BGP-LS-Knotens (209-3) in dem optischen Netzwerk (206);

• Konfigurieren, in dem BGP-LS-Knoten (209-3) in dem optischen Netzwerk (206), der IP-Adresse der GMPLS-UNI in dem ersten Randknoten (EN1) als die IP-Adresse des BGP-LS-Nachbarn; und

• Herstellen, durch das DCN (208), der Verbindung zwischen dem ersten Randknoten (EN1) und dem BGP-LS-Knoten (209-3) in dem optischen Netzwerk (206);

gekennzeichnet durch ein Verteilen, über die hergestellte Verbindung zwischen dem ersten Randknoten (EN1) und dem zweiten Randknoten (EN2), von Link-Network Layer Reachability Information, Link-NLRIs, das einer Richtlinienkonfiguration in dem BGP-LS-Knoten (209-3) in dem optischen Netzwerk (206) unterliegt.


 
2. Verfahren nach Anspruch 1, wobei im Fall eines gerouteten DCN (208) die durch das DCN (208) bereitgestellte Verbindung auf einem Generic Routing Encapsulation-Tunnel, GRE-Tunnel, basiert.
 
3. Verfahren nach Anspruch 1, wobei sich der BGP-LS-Knoten (209-3) an gleicher Position mit einem Kernknoten oder einer Steuerung in dem optischen Netzwerk (206) befindet.
 
4. Verfahren nach Anspruch 1, wobei

• jede Link-NLRI eine Routeridentifikation, Router-ID, von einem von dem ersten und dem zweiten Randknoten (EN1, EN2) in einem lokalen Knotendeskriptorfeld umfasst,

• die Link-NLRI ferner eine IP-Adresse der GMPLS-UNI in dem einen von dem ersten und dem zweiten Randknoten (EN1, EN2) in einem Link-Deskriptor-Feld umfasst,

• die Link-NLRI erweitert ist, um einen Verweis auf die IP-Adresse der GMPLS-UNI in dem einen von dem ersten und dem zweiten Randknoten (EN1, EN2) zu enthalten,

• der Verweis ein vorbestimmter Wert in dem Protokoll-ID-Feld der Link-NLRI ist.


 
5. Verfahren nach Anspruch 4, wobei mindestens eine der ersten und der zweiten Paketnetzinsel eine Network Management System-Steuerung, NMS-Steuerung, oder Software-Defined-Networking-Steuerung, SDN-Steuerung, umfasst, und wobei die NMS- oder SDN-Steuerung konfiguriert ist, um den vorbestimmten Wert zu erkennen und die IP-Adresse an die Router-ID, die in den Link-NLRI enthalten ist, zu binden, und konfiguriert ist, um die Bindung der IP-Adresse und der Router-ID, die in den Link-NLRI enthalten ist, zu speichern.
 
6. Computerprogrammprodukt, umfassend Programmcodeabschnitte, die, wenn sie auf einer oder mehreren Rechenvorrichtungen ausgeführt werden, bewirken, dass die eine oder die mehreren Rechenvorrichtungen alle Schritte eines Verfahrens nach einem der Ansprüche 1 bis 5 durchführen.
 
7. BGP-LS-Knoten (209-3) in einem optischen Netzwerk (206) zur Unterstützung der Bereitstellung einer Verbindung über ein Datenkommunikationsnetz, DCN, (208) des optischen Netzwerks (206) zwischen zwei Paketnetzinseln (204a, 204b), der BGP-LS-Knoten (209-3) umfassend:

• eine Herstellungskomponente (901), die konfiguriert ist, um eine Border Gateway Protocol-Link State-Verbindung, BGP-LS-Verbindung, über das DCN (208) mit einem ersten Randknoten (EN1) herzustellen, wobei sich der erste Randknoten (EN1) in mindestens einer der beiden Paketnetzinseln befindet,

• eine Konfigurationskomponente (902), die konfiguriert ist, um die Internetprotokolladresse, IP-Adresse, einer Generalized Multiprotocol Label Switching User-to-Network Interface, GMPLS-UNI, in dem ersten Randknoten (EN1) als die IP-Adresse eines BGP-LS-Nachbarn zu konfigurieren; und

• eine Verbindungskomponente (903), die konfiguriert ist, um den BGP-LS-Knoten (209-3) mit dem ersten Randknoten (EN1) über eine Verbindung, die durch das DCN (208) bereitgestellt wird, zu verbinden,

dadurch gekennzeichnet, dass der BGP-LS-Knoten (209-3) dafür angepasst ist, von dem ersten Randknoten (EN1) Link-Network Layer Reachability Information, Link-NLRIs, zu empfangen, und ferner dafür konzipiert ist, die Link-NLRIs zu einem zweiten Randknoten (EN2) weiterzuleiten, wobei das Verteilen der Link-NLRIs von dem ersten Randknoten (EN1) an den zweiten Randknoten (EN2) einer Richtlinienkonfiguration in dem BGP-LS-Knoten (209-3)in dem optischen Netzwerk (206) unterliegt.


 


Revendications

1. Procédé de prise en charge de fourniture d'une connexion via un réseau de communication de données, DCN (208), d'un réseau optique (206) entre un premier îlot de réseau par paquets (204a) et un deuxième îlot de réseau par paquets (204b), dans lequel le premier îlot de réseau par paquets (204b) et le deuxième îlot de réseau par paquets (204a) sont connectés au réseau optique (206) au moyen d'une interface utilisateur-réseau à commutation multiprotocole généralisée par étiquette, GMPLS UNI (207a, 207b), respectivement, le procédé comprenant :

• l'établissement d'une connexion d'état de liaison à protocole de passerelle frontière, BGP-LS, via le DCN (208) entre un premier nœud de bord (EN1) du premier îlot de réseau par paquets (204b) et un nœud BGP-LS (209-3) dans le réseau optique (206), et

• l'établissement d'une connexion BGP-LS via le DCN (208) entre un deuxième nœud de bord (EN2) du deuxième îlot de réseau par paquets (204a) et le nœud BGP-LS (209-3) dans le réseau optique (206),

dans lequel l'étape d'établissement de la connexion BGP-LS via le DCN (208) entre le premier nœud de bord (EN1) du premier îlot de réseau par paquets et le nœud BGP-LS (209-3) dans le réseau optique (206) comprend :

• la configuration, dans le premier nœud de bord (EN1), de l'adresse de protocole Internet, IP, du nœud BGP-LS (209-3) dans le réseau optique (206) ;

• la configuration, dans le nœud BGP-LS (209-3) dans le réseau optique (206), de l'adresse IP de la GMPLS UNI dans le premier nœud de bord (EN1) en guise d'adresse IP du voisin de BGP-LS ; et

• l'établissement, par le DCN (208), de la connexion entre le premier nœud de bord (EN1) et le nœud BGP-LS (209-3) dans le réseau optique (206) ;

caractérisé par la distribution, via la connexion établie entre le premier nœud de bord (EN1) et le deuxième nœud de bord (EN2), d'informations d'accessibilité de couche réseau, NLRI, de liaison qui sont soumises à une configuration de politique dans le nœud BGP-LS (209-3) dans le réseau optique (206).


 
2. Procédé selon la revendication 1, dans lequel en cas de DCN routé (208), la connexion fournie par le DCN (208) est basée sur un tunnel d'encapsulation de routage générique, GRE.
 
3. Procédé selon la revendication 1, dans lequel le nœud BGP-LS (209-3) est colocalisé avec un nœud central ou un contrôleur dans le réseau optique (206).
 
4. Procédé selon la revendication 1, dans lequel

• chaque NLRI de liaison comprend une identification, ID, de routeur de l'un parmi les premier et deuxième nœuds de bord (EN1, EN2) dans un champ de descripteurs de nœuds locaux,

• la NLRI de liaison comprend en outre l'adresse IP de la GMPLS UNI dans l'un parmi le premier et le deuxième nœud de bord (EN1, EN2) dans un champ de descripteurs de liaison,

• la NLRI de liaison est étendue pour transporter une référence à l'adresse IP de la GMPLS UNI dans celui parmi le premier et le deuxième nœud de bord (EN1, EN2),

• la référence est une valeur prédéterminée dans le champ d'ID de protocole de la NLRI de liaison.


 
5. Procédé selon la revendication 4, dans lequel au moins l'un des premier et deuxième îlots de réseau par paquets comprend un contrôleur de système de gestion réseau, NMS, ou de réseautage défini par logiciel, SDN, et dans lequel le contrôleur NMS ou SDN est configuré pour reconnaître la valeur prédéterminée et associer l'adresse IP à l'ID de routeur comprise dans la NLRI de liaison et est configuré pour stocker l'association de l'adresse IP et de l'ID de routeur comprise dans la NLRI de liaison.
 
6. Produit programme informatique comprenant des parties de code de programme qui, lorsqu'elles sont exécutées sur un ou plusieurs dispositifs informatiques, amènent le ou les dispositifs informatiques à mettre en œuvre toutes les étapes d'un procédé selon l'une quelconque des revendications 1 à 5.
 
7. Nœud BGP-LS (209-3) dans un réseau optique (206) pour prendre en charge la fourniture d'une connexion via un réseau de communication de données, DCN (208), du réseau optique (206) entre deux îlots de réseau par paquets (204a, 204b), le nœud BGP-LS (209-3) comprenant :

• un composant d'établissement (901) configuré pour établir une connexion d'état de liaison à protocole de passerelle frontière, BGP-LS, via le DCN (208) avec un premier nœud de bord (EN1), dans lequel le premier nœud de bord (EN1) est dans au moins l'un des deux îlots de réseau par paquets,

• un composant de configuration (902) configuré pour configurer l'adresse de protocole Internet, IP, d'une interface utilisateur-réseau à commutation multiprotocole généralisée par étiquette, GMPLS UNI, dans le premier nœud de bord (EN1) en guise d'adresse IP d'un voisin de BGP-LS ; et

• un composant de connexion (903) configuré pour connecter le nœud BGP-LS (209-3) au premier nœud de bord (EN1) via une connexion fournie par le DCN (208),

caractérisé en ce que le nœud BGP-LS (209-3) est conçu pour recevoir du premier nœud de bord (EN1) des informations d'accessibilité de couche réseau, NLRI, de liaison et conçu en outre pour acheminer les NLRI de liaison vers un deuxième nœud de bord (EN2), dans lequel la distribution des NLRI de liaison depuis le premier nœud de bord (EN1) vers le deuxième nœud de bord (EN2) est soumise à une configuration de politique dans le nœud BGP-LS (209-3) dans le réseau optique (206).


 




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Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description




Non-patent literature cited in the description