Patent Description:
Furthermore, the present invention relates to a broadband access network or telecommunications network for being operated comprising a plurality of central office points of delivery, wherein each one of the plurality of central office points of delivery comprises a transport functionality or service and has or is connected to an access functionality being realized by means of a plurality of access nodes that terminate physical subscriber lines serving end users of the telecommunications network, wherein, regarding a specific central office point of delivery, the respective transport functionality or service acts as an ingress router and/or an egress router to a wide area network domain.

Additionally, the present invention relates to a central office point of delivery for operating a broadband access network of a telecommunications network that comprises a plurality of central office points of delivery, wherein the central office point of delivery comprises a transport functionality or service and has or is connected to an access functionality being realized by means of a plurality of access nodes that terminate physical subscriber lines serving end users of the telecommunications network, wherein the transport functionality or service acts as an ingress router and/or an egress router to a wide area network domain.

Furthermore, the present invention relates to a program and a computer-readable medium for an operation of a broadband access network of a telecommunications network comprising a plurality of central office points of delivery.

The exchange of packetized information in broadband communication systems or telecommunications networks, both in fixed-line as in wireless communication systems (or fixed-line communication networks and mobile communication networks) has already grown dramatically and probably will also grow in the future due to the rapid spread of different data services in such communication networks.

In conventionally known architectures involving a plurality of central office points of delivery, such a plurality of central office points of delivery are typically designed such as to almost exclusively rely on backbone infrastructure nodes (or core infrastructure) for handling wide area network traffic, especially internet access traffic, i.e. regarding such wide area network traffic, a specific (considered) central office point of delivery typically acts as an ingress router and/or as an egress router, typically a label edge router, especially in case of an multiprotocol label switching network architecture of the wide area network domain.

This creates drawbacks or is inefficient, especially in case that more or a greater share of regional traffic, e.g. between two central office points of delivery, is to be handled.

With regard to conventionally known architectures, document <CIT> addresses the problem that "long haul" bonding or aggregation of communication links leads to slow transmission through the backbone network, and proposes termination of the bonded/aggregated connection by servers/concentrators before passing the traffic to the backbone. Document <CIT> describes a system for providing conditional bandwidth subscriptions to MPLS label switched paths (LSPs) and document <CIT> describes MPLS segment routing within a leaf/spine fabric. Document <CIT> describes a network including an Ethernet network and a plurality of MPLS networks interconnected by the Ethernet network, in which ethernet encapsulated LSP frames received from one of the MPLS networks at an ingress to the Ethernet network are mapped onto the paths at the ingress to the Ethernet network according to classification identifiers associated with the Ethernet encapsulated LSP frames.

An object of the present invention is to provide a technically simple, effective and cost effective solution for operating a broadband access network of a telecommunications network comprising a plurality of central office points of delivery, wherein each one of the plurality of central office points of delivery comprises a transport functionality or service and has or is connected to an access functionality being realized by means of a plurality of access nodes that terminate physical subscriber lines serving end users of the telecommunications network, wherein the transport functionality or service of a specific central office point of delivery handles and/or transports marked data packets - in a connection oriented manner in a wide area network domain - both as ingress router and/or as egress router, and as an identifier-based switch router functionality of or towards the wide area network domain. A further object of the present invention is to provide a corresponding broadband access network or telecommunications network, a corresponding central office point of delivery and a corresponding system according to the present invention.

The object of the present invention is achieved by a method according to claim <NUM>.

It is thereby advantageously possible according to the present invention to provide a solution such that traffic between different central office points of delivery does not necessarily be routed using a wide area network infrastructure, i.e. using one or a plurality of backbone infrastructure nodes (or core infrastructure) but it is advantageously possible according to the present invention that local traffic is able to be forwarded directly between different central office points of delivery, i.e. from one considered (or specific) central office point of delivery to another (especially neighboring) central office point of delivery. Especially, it is advantageously possible according to the present invention that such traffic, especially local traffic, is able to be routed along a chain of different central office points of delivery (i.e. their respective transport functionality or service), i.e. from a first central office point of delivery to a second central office point of delivery, via another (specific) central office point of delivery; hence the specific central office point of delivery receives marked data packets from the first central office point of delivery and transmits (or forwards) the marked data packets to the second central office point of delivery.

In conventionally known telecommunications networks, typically a certain number of central office points of delivery are provided in order to realize one of the main components of a broadband access network (of the telecommunications network). In addition to the broadband access network, the telecommunications network also comprises or is at least able to access or to be connected to backbone infrastructure nodes (or core infrastructure nodes) for handling wide area network traffic, especially internet access traffic, i.e. non-local traffic. Such backbone infrastructure nodes often provide a multiprotocol label switching functionality (especially in the form of label switch routers, LSRs) especially with regard to such non-local traffic, and the central office points of delivery act as ingress or egress routers, typically label edge routers. However, such an architecture also requires to involve the backbone infrastructure nodes (or core infrastructure nodes) in the handling of traffic that cannot be dealt with internally to a central office point of delivery.

According to the present invention, it is advantageously possible to route traffic among a plurality of different central office points of delivery - especially in case of rather local traffic - without the strict necessity to involve backbone infrastructure nodes (or core infrastructure) for traffic that involves a plurality of central office points of delivery (e.g. either between two adjacent central office points of delivery, or between two (first and second) central office points of delivery that are linked via another (specific) central office point of delivery).

Hence, according to the present invention, the operation of a broadband access network of a telecommunications network is addressed. The broadband access network comprises a plurality of central office points of delivery, and each one of the plurality of central office points of delivery comprises a transport functionality or service and has or is connected to an access functionality being realized by means of a plurality of access nodes that terminate physical subscriber lines serving end users of the telecommunications network. Regarding one considered (or, hereinafter also called 'specific') central office point of delivery, the respective transport functionality or service acts not only as an ingress router and/or an egress router to a wide area network domain that handles and/or transports marked data packets in a connection-oriented manner, but also provides an identifier-based switch router functionality - especially realized by means of an additional function, especially realized by means of a microservice - of or towards the wide area network domain. This means that marked data packets are able to be forwarded directly between, or among, central office points of delivery (or their respective transport functionalities or services), i.e. it is possible to route marked data packets from a first to a second of the plurality of central office points of delivery via the considered central office point of delivery (i.e. in a first step, the specific central office point of delivery receives marked data packets from the first central office point of delivery, and in a second step, transmits the marked data packets to a second central office point of delivery), or to route such marked data packets between two (especially adjacent) central office points of delivery.

According to the present invention, the wide area network domain especially comprises backbone infrastructure nodes (or core infrastructure nodes); however alternatively, the wide area network domain might also essentially consist of the plurality of central office points of delivery and their respective transport functionalities or services.

According to the present invention, it is especially advantageously possible that emergent traffic pattern are able to be served in a very efficient manner:.

Hence, according to the present invention, such drawbacks or inefficiencies, especially in case that more or a greater share of regional traffic is to be handled by the telecommunications network, are able to be either avoided or at least reduced.

According to the present invention, marked data packets (especially IP packets) are used or handled, within (or among the nodes of) the wide area network domain, in order to provide for a connection-oriented handling and/or transport of data packets within the wide area network domain, even though the wide area network domain corresponds to a connectionless network. The marked data packets are marked using an identifier that typically defines the path (through the wide area network domain) that the corresponding data packet is required to use or is transported along. According to the present invention, different implementations of such a marking or the use of such identifiers are able to be realized:.

The telecommunications network according to the present invention might be a fixed-line telecommunications network or a mobile communication network but could also have both aspects, i.e. parts of a fixed-line telecommunications network (or being a fixed-line telecommunications network in such parts) and parts of a mobile communication network (or being a mobile communication network in such parts); such networks are also known under the term fixed-mobile-convergence networks (FMC networks).

According to the present invention the wide area network domain is or corresponds to a multiprotocol label switching, MPLS, domain, wherein the transport functionality or service provides a label edge router functionality such that, regarding the specific central office point of delivery, the transport functionality or service acts as ingress router and/or as egress router of or towards the multiprotocol label switching, MPLS, domain, wherein furthermore the identifier-based switch router functionality acts as label switch router of or towards the multiprotocol label switching, MPLS, domain, wherein the marked data packets are or correspond to MPLS-labelled data packets, handled and/or transported by the multiprotocol label switching domain.

By means of using multiprotocol label switching in the wide area network domain, it is advantageously possible to provide the transport functionality or service of the plurality of central office points of delivery - with regard to the wide area network domain, i.e. northbound - with both the label edge router functionality (i.e. acting as ingress router and/or as egress router of or towards the (wide area network) multiprotocol label switching, MPLS, domain), and the label switch router functionality of or towards the (wide area network) multiprotocol label switching, MPLS, domain.

According to the present invention, the transport functionality or service corresponds to or comprises a switching fabric, wherein the switching fabric comprises at least one spine network node, wherein the at least one spine network node is part of the wide area network domain and acts as identifier-based switch router within the wide area network domain,
wherein especially corresponding spine network nodes of the first and second central office points of delivery likewise act as identifier-based switch router within the wide area network domain.

It is thereby advantageously possible according to the present invention that the telecommunications network and/or the broadband access network, and especially the plurality of central office points of delivery are able to be used more efficiently and more flexibly for transporting marked data packets. Especially, the spine network nodes (of the corresponding central office points of delivery) are especially fully redundant. Such spine network nodes are typically used for aggregation and connectivity for inner traffic within the respective central office point of delivery (so-called southbound traffic). But they are also able to act as label edge routers (LER) in or towards the wide area network domain, i.e. regarding northbound traffic. This means such spine network nodes (or, the transport functionality or service) host the full Internet routing table and put (or push) / remove (or pop) a respective identifier in the form of an MPLS-label, to/from the corresponding IP packets.

According to a further preferred embodiment of the present invention, the at least one spine network node is additionally part of a further network domain - especially a multiprotocol label switching, MPLS, domain - of or among components of the specific central office point of delivery,
wherein the at least one spine network node acts as identifier-based switch router within the further network domain (especially multiprotocol label switching, MPLS, domain).

It is thereby advantageously possible according to the present invention that also as part of the central office point of delivery, a connection-oriented handling of data packets is realized.

According to a further preferred embodiment of the present invention, the switching fabric of the specific central office point of delivery comprises, besides the at least one spine network node, a plurality of leaf network nodes, wherein the leaf network nodes especially provide an edge functionality or service and/or wherein the access nodes of the access functionality are especially connected, respectively, to at least two leaf network nodes of the plurality of leaf network nodes.

It is thereby advantageously possible that the central office points of delivery are especially built on or using a leaf/spine architecture.

According to a further preferred embodiment of the present invention, the corresponding transport functionality or service of each of the plurality of central office points of delivery are part of the wide area network domain, wherein especially a certain number of central office points of delivery are connected such as to be meshed, especially forming 3X3, or 4X4, or nXm meshes of central office points of delivery.

Thereby, it is advantageously possible to efficiently implement the method according to the present invention and to further increase the efficiency in handling user traffic. According to the present invention, nXm meshes correspond to n central office points of delivery (n and m being an integer, e.g. <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>), and each one of these n central office points of delivery is linked to each one of the other central office points of delivery.

According to a further embodiment of the present invention, by means of the corresponding transport functionality or service of each of the plurality of central office points of delivery, the central office points of delivery act a traffic forwarder, besides being an aggregation and service creation point.

Thereby, it is advantageously possible to easily and efficiently implement the inventive method.

Furthermore, according to a preferred embodiment of the present invention, the telecommunications network and/or the broadband access network additionally comprise one or a plurality of backbone identifier-based switch routers, wherein the backbone identifier-based switch routers are part of the wide area network domain, wherein at least one of the backbone identifier-based switch routers additionally comprise or is connected to at least one content delivery network and/or at least one local data center, wherein the at least one content delivery network especially provide for caching internet traffic and/or wherein the at least one local data center provide for storing data, especially sensitive data that should be refrained from being sent to the internet.

Thereby, it is advantageously possible to efficiently implement the method according to the present invention and to be able to additionally also use backbone identifier-based switch routers.

Furthermore, the present invention relates to a broadband access network or telecommunications network according to claim <NUM>.

Additionally, the present invention relates to a central office point of delivery according to claim <NUM>.

Still additionally, the present invention relates to a program comprising a computer readable program code which, when executed on a computer and/or on a network node of a telecommunications network or on a network node of a broadband access network and/or on a transport functionality or service of a central office point of delivery, or in part on the network node of the telecommunications network or in part on the network node of a broadband access network, or in part on the transport functionality or service of the central office point of delivery, causes the computer and/or the network node of the telecommunications network and/or the network node of the broadband access network and/or the transport functionality or service of the central office point of delivery to perform the inventive method.

Furthermore, the present invention relates to a computer-readable medium comprising instructions which when executed on a computer and/or on a network node of a telecommunications network or on a network node of a broadband access network and/or on a transport functionality or service of a central office point of delivery, or in part on the network node of the telecommunications network or in part on the network node of a broadband access network, or in part on the transport functionality or service of the central office point of delivery, causes the computer and/or the network node of the telecommunications network and/or the network node of the broadband access network and/or the transport functionality or service of the central office point of delivery to perform the inventive method.

The drawings described are only schematic and are nonlimiting.

Furthermore, the terms first, second, third and the like in the description and in the claims are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order; this is especially the case for the terms "first step", "second step", etc. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

In <FIG>, a telecommunications network <NUM> according to the present invention is schematically shown, having - preferably - at least a fixed line part. A mobile (or cellular) part might be present as well, as part of the telecommunications network <NUM>, but is not specifically illustrated in <FIG>. User equipment or client devices <NUM>, <NUM> are connected to the telecommunications network <NUM> by means of a (broadband) access network <NUM>. The telecommunications network <NUM> comprises, especially as part of the broadband access network <NUM>, at least one logical or physical central office point of delivery <NUM> that is preferably realized within a (mini) data center and that is especially handling different access requirements, especially different access possibilities, of the client devices <NUM>, <NUM> to network functionalities provided by the telecommunications network <NUM> or via the telecommunications network <NUM>. In addition, the telecommunications network <NUM> typically also comprises - besides the broadband access network <NUM> - a core network <NUM>. The client devices <NUM>, <NUM> are typically connected to the logical or physical central office point of delivery <NUM> by means of a customer premises equipment device <NUM>, <NUM>' or by means of a customer premises equipment functionality that might be built into or realized by the client devices <NUM>, <NUM>. The central office point of delivery <NUM> comprises a switching fabric <NUM> comprising a plurality of spine network nodes and a plurality of leaf network nodes which are not explicitly represented in <FIG>.

<FIG> schematically illustrates in greater detail three central office points of delivery comprising a certain number of components, entities and/or network nodes. The central office points of delivery are part of and/or connected to a wide area network domain <NUM> (that might be part of the core network and/or at least partly overlapping or be separated thereof). The wide area network domain <NUM> handles and/or transports marked data packets <NUM> in a connection-oriented manner. Specifically, <FIG> represents the case that marked data packets <NUM> are to be forwarded, by a specific central office point of delivery <NUM>, from a first central office point of delivery <NUM> and towards a second central office point of delivery <NUM>. This means that, in a first step, the specific central office point of delivery <NUM> receives marked data packets <NUM> from the first central office point of delivery <NUM>, and, in a second step, the specific central office point of delivery <NUM> transmits the marked data packets <NUM> to the second central office point of delivery <NUM>. The forwarding of the marked data packets <NUM> is performed - for each of the central office points of delivery <NUM>, <NUM>, <NUM> - by a transport functionality or service <NUM>. This transport functionality or service <NUM> is designated and represented, in <FIG>, by means of the same reference sign <NUM>; however, it is to be understood that the transport functionality or service <NUM> is especially specific to the respective central office point of delivery <NUM>, <NUM>, <NUM>. Likewise, as part of the respective transport functionality or service <NUM>, a first spine network node <NUM>, and a second spine network node <NUM> is schematically shown. Likewise, leaf network nodes <NUM>, <NUM>, <NUM>, <NUM> are schematically shown as part of the respective transport functionality or service <NUM> of the different central office points of delivery. In the exemplary embodiment shown in <FIG>, the marked data packets <NUM> are transmitted by the second spine network node <NUM> of the first central office point of delivery <NUM> to the first spine network node <NUM> of the specific central office point of delivery <NUM>, and from there forwarded to the first spine network node <NUM> of the second central office point of delivery <NUM>. Hence, the transport functionality or service <NUM> of the specific central office point of delivery <NUM>, does not only act as ingress router and/or as egress router with respect to the wide area network domain <NUM> but also provides an identifier-based switch router functionality of or towards the wide area network domain <NUM>. Thereby, the marked data packets are handled and/or transported in a connection-oriented manner.

According to the present invention, the wide area network domain <NUM> comprises nodes of the transport functionality or service <NUM> (the spine network nodes <NUM>, <NUM>) of the respective central office points of delivery <NUM>, <NUM>, <NUM>. The wide area network domain <NUM> is implemented using or according to multiprotocol label switching technology. Multiprotocol label switching solves inefficiencies in a connectionless IP network, where traditionally paths have to be decided for each and every data packet. Multiprotocol label switching instead uses pre-determined paths (Label Switch Paths) within an IP network across several hops. This better reflects real traffic patterns, which know a specific source (e.g. Netflix peering point at DE-CIX), a destination (e.g. and end user in Munich) as well as sensible network connectivity in-between. And the sensible network connectivity is not coined by "any hop is fine" (from Frankfurt to Munich via Japan and the U. ) but more like the real geographic stretch along sufficient network capacity. Multiprotocol label switching is a highway-like connection-oriented functionality in a connectionless IP network. Hence MPLS is often considered as OSI <NUM> layer (between network and data link layers).

According to the present invention, the transport functionality or service <NUM> - i.e. the spine network nodes <NUM>, <NUM> of the respective central office points of delivery - not only act as ingress and/or egress router of the wide area network domain <NUM> but also as identifier-based switch router functionality (label switch router (LSR) according to multiprotocol label switching parlance). Typically, label switch routers are the heart of an MPLS network or multiprotocol label switching network domain as such routers are able to quickly route (marked) data packets <NUM> without having to check tables or do routing calculations, which would add to the send/receive time of data. The gatekeepers for the MPLS network (domain) (or wide area network domain <NUM>) are the label edge router (or ingress label switch routers). On ingress (of a data packet), such label edge routers add a label (or an identifier information) to each and every IP packet-independent of the actual protocol used (TCP, UDP,. ); on egress, such label edge router remove the respective label (or identifier information) from the data packet. This label (or this identifier information) is the information used by the label switch routers (identifier-based switch router functionality) to do their fast forwarding along the established paths (especially label switch paths.

In <FIG>, a central office point of delivery - or, rather, the specific central office point of delivery <NUM> - is schematically shown. The (specific) central office point of delivery <NUM> comprises, as part of its transport functionality or service <NUM> (or realized by its transport functionality or service <NUM>) a further network domain <NUM>, which is a further multiprotocol label switching, MPLS, domain. The further network domain <NUM> is a network domain of or among components of the specific central office point of delivery <NUM>. The at least one spine network node <NUM>, <NUM> acts as identifier-based switch router within the further network domain <NUM> (multiprotocol label switching, MPLS, domain <NUM>).

<FIG> schematically illustrates two embodiments showing, respectively, a plurality of central office points of delivery being connected or meshed. In representation on the left hand of <FIG>, three central office points of delivery <NUM>, <NUM>, <NUM> form a mesh of central office points of delivery (3x3 mesh), and on the right hand side of <FIG>, four central office points of delivery <NUM>, <NUM>, <NUM>, <NUM> form a mesh of central office points of delivery (4x4 mesh). Especially, on the right hand side of <FIG>, a forwarding path of marked data packets <NUM> is schematically shown between the specific central office point of delivery <NUM> as well as the first central office point of delivery <NUM> and the second central office point of delivery <NUM>. As can be seen from the <FIG>, it is advantageously possible according to the present invention to realize the broadband access network <NUM> without necessarily relying on backbone infrastructure nodes (or core infrastructure) - only the transport functionalities or services of the respective central office points of delivery are meshed or connected with each other (by means of connecting adjacent central office points of delivery), and wide area traffic is nevertheless able to be routed or forwarded. Hence, by means of the transport functionality or service <NUM> (or the spine network nodes <NUM>, <NUM>) also receives the label switch router functionality (or identifier-based switch router functionality) - especially by means of an additional function, especially realized by means of a microservice -, the backbone infrastructure nodes (or core infrastructure) are able to be taken out. The spine network nodes <NUM>, <NUM> are provided with the label switch router functionality (or identifier-based switch router functionality);
Typically, spine network nodes <NUM>, <NUM> (not shown in <FIG>) have a switching capacity of <NUM>-<NUM> times as they need to serve their own central office point of delivery <NUM>, <NUM>, <NUM>, <NUM>. The limiting factor are typically the large buffers (to host the Internet routing tables). However, these buffers are not needed for the label switch router functionality (or identifier-based switch router functionality); hence, a typical spine network node <NUM>, <NUM> normally has sufficient capacity to also provide the label switch router functionality (or identifier-based switch router functionality). The spine network nodes <NUM>, <NUM> are, hence, enabled to forward traffic (i.e. marked data packets) also from outside of the (specific) central office point of delivery <NUM> which is facilitated by means of meshing (or linking, especially directly linking or connecting) different central office points of delivery <NUM>, <NUM>, <NUM>, <NUM> together, especially with respect to adjacent central office points of delivery.

In addition to the two embodiments shown in <FIG>, further embodiment, especially nxm meshes (wherein n and m are integers) are possible and preferred according to the present invention. Hence, besides being an aggregation and service creation point, a central office point of delivery <NUM> is also a traffic forwarder.

Claim 1:
Method for operating a broadband access network (<NUM>) of a telecommunications network (<NUM>) comprising a plurality of central office points of delivery (<NUM>, <NUM>, <NUM>, <NUM>),
wherein each one of the plurality of central office points of delivery (<NUM>, <NUM>, <NUM>, <NUM>) comprises a transport functionality or service (<NUM>) and has or is connected to an access functionality being realized by means of a plurality of access nodes that terminate physical subscriber lines serving end users of the telecommunications network (<NUM>),
wherein, regarding a specific central office point of delivery (<NUM>), the respective transport functionality or service (<NUM>) acts as an ingress router and/or an egress router to a wide area network domain (<NUM>), wherein the wide area network domain (<NUM>) is or corresponds to a multiprotocol label switching, MPLS, domain (<NUM>),
wherein the wide area network domain (<NUM>) handles and/or transports marked data packets (<NUM>) in a connection oriented manner, wherein the marked data packets (<NUM>) are or correspond to MPLS-labelled data packets (<NUM>),
characterized in that the transport functionality or service (<NUM>) corresponds to or comprises a switching fabric (<NUM>) with a leaf/spine architecture, wherein the switching fabric (<NUM>) comprises at least one spine network node (<NUM>, <NUM>), wherein the at least one spine network node (<NUM>, <NUM>) is part of the wide area network domain (<NUM>) and acts as identifier-based switch router within the wide area network domain (<NUM>), and wherein, in order to operate the broadband access network (<NUM>) for providing the access functionality associated with the plurality of central office points of delivery (<NUM>, <NUM>, <NUM>, <NUM>), the at least one spine network node (<NUM>, <NUM>) of the specific central office point of delivery (<NUM>), in addition to acting as ingress router and/or as egress router, acts as label switch router providing an identifier-based switch router functionality of or towards the wide area network domain (<NUM>) such that:
-- in a first step, the specific central office point of delivery (<NUM>) receives marked data packets (<NUM>) from a first central office point of delivery (<NUM>), and
-- in a second step, transmits the marked data packets (<NUM>) to a second central office point of delivery (<NUM>).