Method and nodes for handling a UE which roams into a visited network

Abstract

The embodiments herein relate to a method performed by a control plane node (303) for handling a UE (101) which roams into a visited network (100a). At least the network in which the control plane node (303) is comprised is a MSC network. The control plane node (303) transmits a create chain request message to a service chain controller (305). The create chain request message is a request to create a chain of UPF nodes (308) that user plane packets to or from the UE (101) should traverse. The control plane node (303) receives a create chain response message from the service chain controller (305). The create chain response message indicates that the requested chain has been created.

Claims

1. A method performed by a control plane node for handling a user equipment (UE) that roams into a visited network, wherein the control plane node is comprised in a first network, the first network being one of the visited network and a home network, wherein the first network in which the control plane node is comprised is a Mobile Service Chaining (MSC) network, the method comprising: after determining that the UE roams into the visited network, transmitting a create chain request message to a service chain controller, wherein the create chain request message is a request to create a chain of User Plane Function (UPF) nodes for processing user plane packets to or from the UE, and the create chain request message comprises an identity of the UE; and receiving from the service chain controller a create chain response message that is responsive to the create chain request message, wherein the create chain response message indicates that the requested chain has been created and wherein the create chain response message comprises information that indicates at least one of an address and an identifier of a user plane edge point in the first network in which the control plane node is comprised.

2. The method according to claim 1, further comprising: transmitting a create session request message a second network which the control plane node is not comprised in, wherein the create session request message comprises at least one of the address and identifier of the user plane edge point; and receiving a create session response message from the second network which the control plane node is not comprised in.

3. The method according to claim 1, further comprising: receiving a create session request message from a second network which the control plane node is not comprised in; and transmitting a create session response message to the second network which the control plane node is not comprised in.

4. The method according to claim 2, wherein the create session request message is General packet radio service Tunneling Protocol message.

5. The method according to claim 2, wherein the create session request message comprises information indicating a user plane edge point which the home network shall use for downlink traffic to the UE.

6. The method according to claim 2, wherein the create session request message is based on 3GPP EPC when the visited network is unaware of which type the home network is.

7. The method according to claim 1, wherein the control plane node is comprised in the visited network, and wherein the method further comprises: selecting the user plane edge point in the visited network from a plurality of possible user plane edge points.

8. The method according to claim 1, wherein the control plane node is comprised in the visited network, and wherein the method further comprises: transmitting information indicating a plurality of possible user plane edge points in the visited network to the home network for selection of the user plane edge point.

9. The method according to claim 1, wherein the control plane node is comprised in the home network, and wherein the method further comprises: transmitting an update location identity (ID) request message to an address advertisement node, wherein the update location ID request message comprises information indicating at least one of an user plane edge point of the visited network and an user plane edge point of the home network; and receiving an update location ID response message from the address advertisement node.

10. The method according to claim 1, wherein the control plane node is comprised in the home network, and the method further comprises allocating an address to the UE.

11. The method according to claim 10, wherein the allocation of the address is coordinated with an address advertisement node.

12. The method according to claim 1, wherein the address of the user plane edge point is an Internet Protocol(IP) address and the identifier is a Tunnel Endpoint Identifier.

13. The method according to claim 1, wherein the control plane node comprises information indicating that the home network is one of: an MSC network and a Third Generation Partnership Project Evolved Packet Core network.

14. A control plane node for handling a user equipment (UE) which roams into a visited network, wherein the control plane node is comprised in a first network, the first network being one of the visited network and a home network, wherein the first network in which the control plane node is comprised is a Mobile Service Chaining (MSC) network, the control plane node comprising: a memory; and a processor coupled to the memory, wherein the control plane node is configured to: transmit a create chain request message to a service chain controller when the UE roams into the visited network, wherein the create chain request message is a request to create a chain of User Plane Function (UPF) nodes for processing user plane packets to or from the UE, and wherein the create chain request message comprises an identity of the UE; receive a create chain response message from the service chain controller, wherein the create chain response message indicates that the requested chain has been created and wherein the create chain response message comprises information which indicates at least one of an address and an identifier of a user plane edge point in the first network in which the control plane node is comprised; transmit a create session request message to a second network which the control plane node is not comprised in, wherein the create session request message comprises at least one of the address and identifier of the user plane edge point; and receive a create session response message from the second network which the control plane node is not comprised in.

15. The control plane node according to claim 14, being further configured to: receive a create session request message from a second network which the control plane node is not comprised in; and to transmit a create session response message to the second network which the control plane node is not comprised in.

16. The control plane node according to claim 14, wherein the create session request message is General packet radio service Tunneling Protocol message.

17. The control plane node according to claim 14, wherein the create session request message comprises information indicating a user plane edge point.

18. The control plane node according to claim 14, wherein the create session request message is based on 3GPP EPC.

19. The control plane node according to claim 14, wherein the control plane node is comprised in the visited network, and wherein the control plane node is further configured to: select the user plane edge point in the visited network from a plurality of possible user plane edge points.

20. The control plane node according to claim 14, wherein the control plane node is comprised in the visited network, and wherein the control plane node is further configured to: transmit information indicating a plurality of possible user plane edge points in the visited network to the home network for selection of the user plane edge point.

21. The control plane node according to claim 14, wherein the control plane node is comprised in the home network, and wherein the control plane node is further configured to: transmit an update location identity (ID) request message to an address advertisement node, wherein the update location ID request message comprises information indicating at least one of an edge point of the visited network and an edge point of the home network; and to receive an update location ID response message from the address advertisement node.

22. The control plane node according to claim 14, being further configured to: allocate an address to the UE.

23. The control plane node according to claim 22, wherein the allocation of the address is coordinated with an address advertisement node.

24. The control plane node according to claim 14, wherein the address of the user plane edge point is an Internet Protocol, IP, address and the identifier is a Tunnel Endpoint Identifier, TEID.

25. The control plane node according to claim 14, wherein the control plane node comprises information about which type the home network is.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The embodiments herein will now be further described in more detail in the following detailed description by reference to the appended drawings illustrating the embodiments and in which:

(2) FIG. 1 is a schematic block diagram illustrating an example of a home-routed roaming architecture.

(3) FIGS. 2a and 2b are signaling diagrams illustrating an example of an initial attach.

(4) FIG. 3 is a schematic block diagram illustrating embodiments of a communications system.

(5) FIG. 4 is a schematic block diagram illustrating embodiments of a communications system in a non-roaming scenario.

(6) FIG. 5a, 5b, 5c are schematic block diagrams illustrating embodiments of a communications system.

(7) FIG. 6 is a schematic block diagram illustrating embodiments of a communications system.

(8) FIG. 7 is a schematic block diagram illustrating embodiments of a communications system.

(9) FIG. 8a, 8b are signaling diagrams illustrating embodiments of a method.

(10) FIG. 9 is a signaling diagram illustrating embodiments of a method.

(11) FIG. 10 is a signaling diagram illustrating embodiments of a method.

(12) FIG. 11 is a schematic block diagram illustrating embodiments of a communications system.

(13) FIG. 12a, 12b are signaling diagrams illustrating embodiments of a method where both the home network and the visited network are based on MSC.

(14) FIG. 13 is a signaling diagram illustrating embodiments of a method where the home network is based on MSC and the visited network is a legacy EPC network.

(15) FIG. 14 is a schematic block diagram illustrating embodiment of conversion of a payload.

(16) FIG. 15 is a signaling diagram illustrating embodiments of a method where the visited network is based on MSC and the home network is a legacy EPC network.

(17) FIG. 16 is a flow chart illustrating embodiments of a method performed by a control plane node.

(18) FIG. 17 is a schematic block diagram illustrating embodiments of a control plane node.

(19) FIG. 18 is a flow chart illustrating embodiments of a method performed by a service chain controller.

(20) FIG. 19 is a schematic block diagram illustrating embodiments of a service chain controller.

(21) FIG. 20 is a flow chart illustrating embodiments of a method performed by a user plane edge point.

(22) FIG. 21 is a schematic block diagram illustrating embodiments of a user plane edge point.

(23) The drawings are not necessarily to scale and the dimensions of certain features may have been exaggerated for the sake of clarity. Emphasis is instead placed upon illustrating the principle of the embodiments herein.

DETAILED DESCRIPTION

(24) As mentioned above, there is a need for a new mobile core network architecture. For the new mobile core network architecture, some terms needs to be defined.

(25) A service chain may be defined as a sequence of service functions that user plane packets traverse. Using other words, a service chaining solution uses SDN technology to intelligently chain service functions so that traffic from each subscriber only traverses a particular set of service functions as defined by the policy for that particular subscriber. This solution can also be used to apply service chaining policies to operator/user defined services. For example, an operator can configure a service chaining policy such that only web traffic is sent to a content optimization service.

(26) FIG. 3 illustrates an example of a communications system 300 implementing MSC. Mobile Service Chaining, abbreviated MSC may be described as the ability of the network to combine service chaining with mobility handling.

(27) The MSC architecture is divided into a control plane, a user plane and a management plane. The UE 101 communicates with the control and user plane via one or more accesses. An access node is exemplified with a RAN node 105 in FIG. 3, but the concept is equally applicable to all accesses including fixed access. The RAN node 105 may be for example a BS, a NodeB, an eNB, a RNC or any other element capable to communicate with the UE 101.

(28) The UE 101 may be a device by which a subscriber may access services offered by an operator's network and services outside operator's network to which the operator's radio access network and core network provide access, e.g. access to the Internet. The UE 101 may be any device, mobile or stationary, enabled to communicate in the communications network, for instance but not limited to e.g. user equipment, mobile phone, smart phone, sensors, meters, vehicles, household appliances, medical appliances, media players, cameras, Machine to Machine (M2M) device, Device to Device (D2D) device, Internet of Things (IoT) device or any type of consumer electronic, for instance but not limited to television, radio, lighting arrangements, tablet computer, laptop or Personal Computer (PC). The UE 101 may be portable, pocket storable, hand held, computer comprised, or vehicle mounted devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another device or a server.

(29) The control plane comprises all control plane logic, allowing for a strict separation between control and user plane. The control plane comprises a control plane node 303. The control plane node 303 may comprise the control plane parts of the following legacy node functions: MME 108. PCRF 125. SGW 110. PGW 113.

(30) Examples of interfaces that are terminated in the control plane nodes are: S1-AP, S1-MME, S6a, Rx, S8 (possibly also Gx if a separate PCRF 125 is required). The control plane node 303 may be referred to as e.g. a Session Manager (SM).

(31) The control plane using the MSC architecture may further comprise a service chain controller 305 which may act as a control and user plane (e.g. SDN) controller and which may select a User Plane Function (UPF) node 308, configures Forwarding Elements (FE) 313 executes handovers. The service chain controller 305 may be referred to as a Mobile Service Chain Controller (MoSCC).

(32) The term legacy mentioned above refers to something that is based on older, outdated protocols. For example, a legacy network may be a 3GPP EPC network in relation to a MSC network. A legacy node may be a node which is comprised in a legacy network.

(33) The user plane may contain three types of function nodes: FE 313, UPF nodes 308 and address advertisement node 310.

(34) The term user plane edge point 308, 310 may be used to refer to any of the UPF node 308 and the address advertisement node 310. The user plane edge point 308, 310 may be referred to as a user plane edge node, a user plane edge module, a user plane edge unit or a user plane edge function. The user plane edge point 308, 310 may be a user plane entry point or a user plane exit point of the visited network 100a or the home network 100b. A user plane entry point may also be referred to as a user plane ingress point and a user plane exit point may also be referred to as a user plane egress point.

(35) An FE 313 forwards each packet to one of its ports based on rules it has received from the control plane node 303. An FE 313 may forward a packet through one or more UPF nodes 308. An FE 313 is only concerned with the actual forwarding; it does not classify or modify a packet.

(36) A UPF node 308 processes user plane packets. The processing may include altering the packet's payload and/or packet header. UPF nodes 308 are not expected to know topological information regarding the chain, including which other UPF nodes 308 are in the chain and how to reach them. A UPF node 308 may serve multiple UEs 101, and may keep context per UE. A UPF node 308 handles a collection of flows.

(37) The address advertisement node 310 enables an anchorless network; i.e. a network without a mobility anchor point. An address advertisement node 310 advertises a range of addresses/prefixes towards an outer network. The address may be e.g. an IP address. This may be Internet or an operator-internal network. A single IP address/prefix may be advertised by multiple IAPs. If the IP address of a specific device is advertised by multiple IAPs, then packets for that device can enter the network via any of those IAPs. Similarly, an anchored approach can be achieved by allowing only a single Internet Protocol (IP) Advertisement Point (IAP) to advertise the IP address for that device. The address advertisement node 310 may be referred to as an IAP.

(38) The control plane may comprise a Location Registry (LR) 315 (not shown in FIG. 3, but in FIG. 4). This is a table of entries, where each entry is a mapping from UE IP address/prefix to UE IDentifier (ID) and current UE location. The may be encoded as a BS ID. When a UE 101 moves from one RAN node 105 to another, the control plane ensures that a BS ID in the LR is updated with the new location. The BS ID is an example of a location identity (location ID) which indicates the identity of the RAN node 105 which serves the UE 101. The location identity may also be referred to as an eNB ID. An address advertisement node 310 may be only used for downlink packets. For each downlink packet, the address advertisement node 310 does: 1) Query the LR based on the destination IP address of the packet in order to retrieve device ID and location ID; 2) Tag the packet with an identity. The identity may be at least one of an UE ID and a location ID such as e.g. a BS ID; The UE ID may be an optional ID to transmit in step 2). 3) Forward the packet to an FE 313. Note that the LR can be implemented in an optimized and distributed fashion. E.g. the IAP query may be performed towards an IAP-internal cache.

(39) A FE 313 forward packets to different UPF nodes 308 and RAN nodes 105 according to which service chain the packets need to traverse and where the corresponding UEs 101 are located. Such information may be added to the packet as tags by the classifiers. A classifier (CL) is a UPF node 308 that determines which service chain a packet takes based on the packet header and rules it has received from the control plane node 303. A CL may change the packet's header, e.g. adding a tag to indicate which service chain the packet traverses. A CL may contact the control plane node 303 when a packet cannot be classified, or it may drop such packet. A CL may be a downlink or uplink CL.

(40) Tags are logically expressed with a name/value pair. A packet may have one or more tags. There are multiple ways to carry tags in packets. In certain cases, an existing protocol element can act as tag value; e.g. an IP address can acts as UE ID.

(41) Putting it all together, an uplink packet would traverse the RAN node 105 and one or more Fes 313. Each FE 313 may forward the packet via one or more UPF nodes 308. Similarly, a downlink packet would traverse the address advertisement node 310, one or more FEs 313 and a RAN node 105. In both uplink and downlink, at least one UPF node 308 may act as a CL.

(42) It should be noted that the communication links in the communications system illustrated in FIG. 3 may be of any suitable kind including either a wired or wireless link. The link may use any suitable protocol depending on type and level of layer (e.g. as indicated by the Open Systems Interconnection (OSI) model) as understood by the person skilled in the art.

(43) FIG. 4 is another example of the communications system 300 implementing MSC. The RAN node 105 is exemplified with an eNB 105 in FIG. 4. The UE 101 illustrated in FIG. 4 is not roaming, i.e. it is in its home network 100b. In such example, the LR 315 may hold the location, i.e. the base station 101, to which the UE 101 is currently connected. FIG. 4 further illustrates two UPFs 308 (UPF1 and UPF2) in the uplink direction, and two UPFs 308 (UPF1 and UPF2) in the downlink direction. FIG. 4 illustrates a Classifier-Uplink (CL-UL) 320a which is a classifier in the uplink direction and a Classifier-Downlink (CL-DL) 320b which is a classifier in the downlink direction. As mentioned earlier, a classifier is a type of UPF that determines which service chain a packet takes based on the packet header and rules it has received from the control plane node 303. The CL-UL 320a in the uplink direction is located between the eNB 105 and the UPFs 308. The CL-DL 320b in the downlink direction is located between the UPFs 308 and the IAP 310. The IAP 310 is in the downlink direction and is connected to the LR 315.

(44) The MSC architecture may be organized in different ways such as e.g. the following three scenarios: 1. The visited network 100a is based on MSC and the home network 100b is a legacy EPC network. 2. Both the visited network 100a and home network 100b are based on MSC. 3. The visited network 100a is a legacy EPC network and the home network 100b is based on MSC.

(45) These three scenarios are illustrated in FIGS. 5a, 5b and 5c. FIG. 5a illustrates scenario 1 where the visited network 100a is based on MSC and the home network 100b is a legacy EPC network (not using MSC). FIG. 5b illustrates scenario 2 where both the visited network 100a and home network 100b are based on MSC. FIG. 5c illustrates scenario 3 where the visited network 100a is a legacy EPC network and the home network 100b is based on MSC. Only some of the nodes in the MSC network in FIG. 3 and the legacy EPC network in FIG. 1 are illustrated in FIGS. 5a, 5b and 5c for the sake of simplicity. However, the networks illustrated in FIGS. 5a, 5b and 5c may comprise any of the nodes illustrated in FIGS. 1 and 3. The dotted box around the UPF node 308 and the address advertisement node 310 indicates the user plane edge point 308, 310 which may be used to refer to any of the UPF node 308 and the address advertisement node 310.

(46) Scenario 1 is also illustrated in FIG. 6, where the home network is a legacy EPC network and the visited network 100a is based on MSC and when a UE 101 is roaming in to the visited network 100a. Scenario 2 is also illustrated in FIG. 7, where both the home network 100b and the visited network 100a are based on MSC and when a UE 101 is roaming in to the visited network 100a. In scenario 2, both the home network 100b and the visited network 100a may have their own UPFs 308. The RAN node 105 is exemplified with an eNB 105 in FIG. 7. In FIG. 7, only the home network 100b comprises the IAP 310 and the LR 315. In the home network 100b, there are two UPFs 308 (UPF3 and UPF4) in the uplink and two UPFs 308 (UPF3 and UPF4) in the downlink. The downlink of the home network 100b also comprises a CL-DL 320b, an IAP 310 and a LR 315. The visited network 100a which is visited by the UE 101 comprises two UPFs 308 (UPF1 and UPF2) and a CL-UL 320a in the uplink and two UPFs 308 (UPF1 and UPF2) and a CL-DL 320b in the downlink.

(47) When the UE 101 roams in a communication system based on MSC, the visited network 100a is unaware about the home network architecture; it could be Mobile Service Chained or a legacy PGW. In the situation where the home network 100b is based on MSC, the LR 315 cannot contain (base station) location information because the home network 100b does not know the location of the UE 101 in the visited network 100a. In order to ease migration to the Mobile Service Chaining architecture the different architectures have to be able to co-exist. With the embodiments herein, roaming is supported in the Mobile Service Chaining architecture, in addition to letting the Mobile Service Chaining architecture co-exist with legacy networks in roaming cases.

(48) The three scenarios will now each be described in more detail.

(49) Scenario 1: Visited Network 100a is Based on MSC, Home Network 100b is Legacy EPC

(50) FIG. 8a and FIG. 8b show a UE 101 attaching to the visited network 100a for the first time. FIG. 8a comprises steps 801-815 and FIG. 8b comprises steps 816-824. Such attach may be referred to as an IMSI Attach. The visited network 100a is based on MSC and the home network 100b is based on EPC. The RAN node 105 is exemplified with an eNB 105 in FIGS. 8a and 8b. When the UE 101 is in a visiting network 100a, e.g. a VPLMN, which applies MSC, then special treatment is needed to ensure backwards compatibility with the home network 100b, e.g. HPLMN, applying EPC, described in box 809. The Database (DB) 123 in FIG. 8 is the same as the HSS 123 in the home network 100b. In FIG. 8, the control plane node 303 is represented by a SM, the service chain controller 305 is represented by a MoSCC and the address advertisement node 310 is represented by an IAP. To differentiate between the IAPB, the IAP 310 located in the visited network 100a is denoted IAP and the IAP located in the home network is denoted IAP. The method in FIG. 8 comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(51) Step 801

(52) This step is seen in FIG. 8a. This step corresponds to step 201 in FIG. 2a. The UE 101 transmits an attach request message to the eNB 105.

(53) Step 802

(54) This step is seen in FIG. 8a. The eNB 105 transmits an initial UE message to the SM 303.

(55) Step 803

(56) This step is seen in FIG. 8a. If no UE context for the UE 101 exists anywhere in the network, if the Attach Request (sent in step 801) was not integrity protected, or if the check of the integrity failed, then authentication and NAS security setup to activate integrity protection and NAS ciphering may be executed. This step involves the UE 101, the SM 303 and the DB 123.

(57) Step 804

(58) This step is seen in FIG. 8a. The SM 303 may send an identity request message to the UE 101, and the UE 101 sends an identity response message to the Sm 303. The identity response message comprises the identity (e.g. the IMSI) of the UE 101.

(59) Step 805

(60) This step is seen in FIG. 8a. The SM 303 may send the ME Identity Check Request message to an EIR 130. The EIR 130 may respond to the Sm 303 with an ME Identity Check Ack (Result) message.

(61) Step 806

(62) This step is seen in FIG. 8a. The SM 303 may send an Update Location Request message to the DB 123.

(63) Step 807

(64) This step is seen in FIG. 8a. The DB 123 may acknowledge the Update Location message by sending an Update Location Ack message to the SM 303.

(65) Step 808

(66) This step is seen in FIG. 8a. The SM 303 applies local policies.

(67) Step 809

(68) This step is seen in FIG. 8a. This step is described in more detail in FIG. 9 below.

(69) Step 810

(70) This step is seen in FIG. 8a. The SM 303 sends a create session request message to the PGW 113 in the home network 100b. With the create session request message, information which indicates where downlink data should be sent to, i.e. a user plane edge point such as the IAP 310. The request message may for example comprise at least one of the address of the IAP 310 and the identity of the IAP 310.

(71) Step 811

(72) This step is seen in FIG. 8a. The PGW 113 allocates an IP address to the roaming UE 101.

(73) Step 812

(74) This step is seen in FIG. 8a. The PGW 113 sends a create session response message to the SM 303.

(75) Step 813

(76) This step is seen in FIG. 8a. The PGW 113 may send the first downlink data to the IAP 310 (if no handover).

(77) Step 814

(78) This step is seen in FIG. 8a. The IAP 310 may send a payload notification to the SM 303.

(79) Step 815

(80) This step is seen in FIG. 8a. The SM 303 sends an initial context (attach accept), setup request to the eNB 105.

(81) Step 816

(82) This step is seen in FIG. 8b. This step corresponds to step 229 in FIG. 2b. The eNB 105 sends an RRC Connection Reconfiguration message to the UE 101.

(83) Step 817

(84) This step is seen in FIG. 8b. This step corresponds to step 230 in FIG. 2b. The UE 101 sends the RRC Connection Reconfiguration Complete message to the eNB 105.

(85) Step 818

(86) This step is seen in FIG. 8b. The eNB 105 sends the Initial Context Response message to the SM 303.

(87) Step 819

(88) This step is seen in FIG. 8b. This step corresponds to step 232 in FIG. 2b. The UE 101 sends a Direct Transfer message to the eNB 105.

(89) Step 820

(90) This step is seen in FIG. 8b. The eNB 105 sends a Uplink (UL) NAS Transport message to the SM 303. This message may indicate that the attach has been completed.

(91) Step 821

(92) This step is seen in FIG. 8b. This step illustrates when there is pending Downlink (DL) payload waiting to be transmitted to the UE 101. This step is described in detail with reference to FIG. 10 below.

(93) Step 822

(94) The UE 101 may send first uplink data to the PGW 113 in the home network 100b. The first uplink data may go via at least one UPF 308 on its way to the PGW 113.

(95) Step 823

(96) The PGW 113 may send first downlink data to the UE 101. The first downlink data may go via the IAP 310 and at least one UPF 308 on its way to the UE 101.

(97) Step 809 in FIG. 8a is illustrated in more detail in FIG. 9. In particular, FIG. 9 illustrates the IMSI Attach to the VPLMN using the MSC concept. The method in FIG. 9 comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(98) Step 901

(99) The SM 303 sends a create chain request message to the MoSCC 305.

(100) Step 902

(101) The MoSCC 305 sends instructions to the UPF 308 to start to prepare to serve UE 101. The instructions may comprise the UE ID or the UE IP address may be used as a key. The UPFs 308 are configured to serve this UE 101. The instructions may be sent in a message referred to as create mobile service chain request.

(102) In addition to the instructions in step 902, the MoSCC 305 in the visited network 100a may send a user plane edge point setup request message to the IAP 310 in the visited network 100a (not illustrated in FIG. 9, but it is illustrated in step 1203 in FIG. 12a). The user plane edge point setup request message is a request to setup and prepare the user plane edge point 308, 310. The IAP 310 will setup the GTP and handle the S8-U plane.

(103) Step 903

(104) The UPF 308 prepares to serve the UE 101 and sends a confirmation to the MoSCC 305 to confirm that they are prepared to serve the UE 101. The confirmation may be sent in a message referred to as create mobile service chain response.

(105) The IAP 310 in the visited network 100a may also send a user plane edge point setup response message to the MoSCC 305 in the visited network 100a (this step is not illustrated in FIG. 9, but it is illustrated in step 1204 in FIG. 12a). Information about IP address and Tunnel Endpoint IDentifier (TEID) associated with the UE 101 is comprised in the response message. The user plane edge point setup response message indicates that the user plane edge point has been setup.

(106) Step 904

(107) The MoSCC 305 sends a create chain response message to the SM 303. With this response message, the SM 303 knows that the chain has been created. The create chain response message may comprises information which indicates the at least one of the address and identifier of the user plane edge point 308, 310 in the network in which the SM 303 is comprised and which the user plane packets should travers in the created chain. The user plane edge point 308, 310 may be at least one of an IAP 310 or one or more UPFS 308.

(108) Step 822 in FIG. 8b will now be described in more detail. FIG. 10 illustrates step 822 in more detail and illustrates downlink traffic for a UE 101 in connected mode using the Mobile Service Chaining concept. In FIG. 10, the SM 303 and the LR 315 are co-located in one node. The RAN node 105 is exemplified with an eNB 105 in FIG. 10. The method illustrated in FIG. 10 comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(109) Step 1001

(110) Downlink data to be delivered to and address (e.g. the IP address of the UE 101) is received at the IAP 310. The IAP 310 may check if the IP address of the UE 101 is included in an already existing service chain.

(111) Step 1002

(112) The IAP 310 sends a payload notification message to the MoSCC 305. The payload notification informs the MoSCC 305 about that there is downlink data to be delivered to an address, e.g. the IP address of the UE 101. The IAP 310 is located in the downlink direction.

(113) Step 1003

(114) The IAP 310 buffers the downlink data.

(115) Step 1004

(116) The MoSCC 305 sends a payload notification message to the SM/LR 303, 315. The payload notification transmitted to the SM/LR 303, 315 may comprise a request for the location of the UE 101.

(117) Step 1005

(118) The SM/LR 303, 315 sends a modify bearer request message to the MoSCC 305. The modify bearer request message may comprise the address of the UE 101 which was requested in step 1004.

(119) Step 1006

(120) The MoSCC 305 may send a Service Start Trigger message to the UPF 308. The service start trigger message may comprise the identity of the UE 101.

(121) Step 1007

(122) The MoSCC 305 may send an Update eNB ID Request message to the IAP 310. The Update eNB ID request message may comprise the address of the eNB 105 for the payload. The address may be seen as a tag.

(123) Step 1008

(124) The IAP 310 may send an Update eNB ID Response to the MoSCC 305 which acknowledges the receipt of the request message in step 1007.

(125) Step 1009

(126) The MoSCC 305 sends a Modify Bearer Response message to the SM, LR 303, 315 which is a response to the request message in step 1005.

(127) Step 1010

(128) The first downlink data is transmitted from the IAP 310 to the UE 101.

(129) Scenario 2: Home Network 100b and Visited Network 100a are Both Based on MSC

(130) FIG. 11 illustrates an example when both the home network 100b and the visited network 100a are based on MSC, i.e. scenario 2. The RAN node 105 is exemplified with an eNB 105 in FIG. 11. In FIG. 11, both the visited network 100a and the home network 100b may have their own UPFs 308. The LR query in the visited network 100a will result in a location ID such as e.g. a BS ID. The IAP 310 is configured to receive packets from the home network 100b. It is not publicly announcing IP addresses from the home network 100b. The home network 100b may do its own classification of incoming roaming packets. The LR query will not result in a location ID in the home network 100b, but in a user plane edge point to at the visited network 100a (called IAP 310 in FIG. 11). The user plane edge point 308, 310 may be an entry point or an exit point. In home-routed roaming, the UE 101 will have an IP address from the home network 100b.

(131) In the roaming case, the home network 100b does not know the location of the UE 101 in the visited network 100a. The home network 100b only knows that this is a roaming case. To solve this, the LR 315 of the home network 100b does not store a location but a user plane edge point 308, 310 in the visited network 100a. This user plane edge point 308, 310 is denoted with IAP 310 in the FIG. 11. The actual value of such user plane edge point 308, 310 in the LR 315 may be an IP address, a Domain Name Server (DNS) name of the IAP 310, etc. When the packet traverses the classifier(s) 320 and UPF(s) 308 in the home network 100b, the packet does not carry a tag with a location ID such as e.g. a BS ID as described earlier, but a tag with the user plane edge point 308, 310 in the visited network 100a. At the end of the chain in the home network 100b this user plane edge point 308, 310 may be used to forward to the correct visited network 100a.

(132) The IAP 310 user plane edge point 308, 310 may be similar to an ordinary IAP 310 in the non-roaming case. One difference may be that no IP address range is announced outwards. Only a lookup is made to the LR 315 (in the visited network 100a), in order to find out the actual location of the UE 101. The rest of the procedure is as described above.

(133) Multiple IAP instances may be involved in a roaming scenario between a particular visited network 100a and a particular home network 100b. Exactly which IAP 310 instance to use for this UE 101 may be based on pre-configuration or dynamic negotiation when the UE 101 attaches. It is also possible that multiple IAP 310 instances are used for a single UE 101. Depending on aspects like network topology or real-time load balancing a particular IAP 310 instance is chosen.

(134) The IAP 310 is the user plane edge point 308, 310 (e.g. an entry point) in the downlink direction. Similarly, in the uplink, a user plane edge point 308, 310 (e.g. an entry point) is needed. In general, a UPF 308 in the home network 100b may be the uplink user plane edge point 308, 310 (e.g. an entry point). In the example FIG. 11, this UPF 308 is an uplink classifier 320a.

(135) FIGS. 12a and 12b are signaling diagrams illustrating an example of the initial attach where both the home network 100b and the visited network 100a are based on MSC (scenario 1). In FIG. 12a and FIG. 12b, the control plane node 303 is represented by a SM, the service chain controller 305 is represented by a MoSCC and the address advertisement node 310 is represented by an IAP 310. FIG. 12a comprises steps 1201-1209 and FIG. 12b comprises steps 1210-1215.

(136) The Create Session procedure between the home network 100b and the visited network 100a is GTP based in order to be backwards compatible. Although not shown in FIGS. 12a and 12b, there might be a capability exchange between the different networks 100a, 100b opening up for other ways to establish the connection between the visited network 100a and the home network 100. It might also be negotiated between operators in the Service Level Agreement (SLA), and then configured in the SM 303, based on the PLMN, which architecture to use. If it is known from the capability information that both networks are based on MSC, then the Create Session Request does not need to be GTP-based. FIGS. 12a and 12b use the example where the Create Session Request is GTP-based.

(137) The method exemplified in FIGS. 12a and 12b comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(138) Step 1201

(139) This step is seen in FIG. 12a. The SM 303 in the visited network 100a has local policies. The local policies may be roaming policies regarding QoS, the amount of bandwidth that is allowed for the roaming subscriber(s) so that the SLA is not broken. If no PCRF exist, then these QoS limits also need to be set, e.g. they are set locally. In some embodiments, either step 1207 is performed or step 1208 is performed. In other embodiments, both steps 1207 and 1208 are performed.

(140) Step 1202

(141) This step is seen in FIG. 12a. The SM 303 in the visited network 100a sends a create chain request message to the MoSCC 305 in the visited network 100a.

(142) Step 1203

(143) This step is seen in FIG. 12a. The MoSCC 305 in the visited network 100a sends a user plane edge point setup request message to the IAP 310 in the visited network 100a. The user plane edge point setup request message is a request to setup and prepare the user plane edge point 308, 310. The IAP 310 will setup the GTP and handle the S8-U plane.

(144) The MoSCC 305 may also send instructions to the UPF 308 to prepare for serving the UE 101. A UPF 308 may be configured with some information about the UE 101 in order to perform its task (e.g. a bandwidth limiter UPF needs to get configured with the max bandwidth of this particular UE 101). This step is not illustrated in FIG. 12, but it is illustrated in step 902 FIG. 9. In some embodiments, the instructions to the UPF 308 to prepare for serving the UE 101 is sent together with the user plane edge point setup request message. In other embodiments, the instruction to prepare and the user plane edge point setup request message are separate messages.

(145) Step 1204

(146) This step is seen in FIG. 12a. The IAP 310 in the visited network 100a sends a user plane edge point setup response message to the MoSCC 305 in the visited network 100a. Information about IP address and TEID associated with the UE 101 is comprised in the response message. The user plane edge point setup response message indicates that the user plane edge point has been setup.

(147) The MoSCC 305 may also send a response to the instructions to the UPF 308 to prepare for serving the UE 101. This step is not illustrated in FIG. 12, but it is illustrated in step 903 in FIG. 9. In some embodiments, the response to the instructions to the UPF 308 to prepare for serving the UE 101 is sent together with the user plane edge point setup response message. In other embodiments, the response to instructions to prepare and the user plane edge point setup response message are separate messages.

(148) Step 1205

(149) This step is seen in FIG. 12a. The MoSCC 305 in the visited network 100a sends a create chain response message to the SM 303 in the visited network 100a. The create chain response message is a response to the request message in step 1202. The response message comprises the information about IP address and TEID associated with the user plane edge point 308, 310. In other words, information (e.g. IP address) for the UPF 308 in the visited network 100a that will receive downlink data from the home network 100b.

(150) Step 1206

(151) This step is seen in FIG. 12a. The SM 303 in the visited network 100a sends a create session request message to the SM 303 in the home network 100b. Information about the IP address and TEID associated with the UE 101 is included in the Create Session Request message towards the home network 100b.

(152) Either the visited network 100a selects the user plane edge point 308, 310 (in that case only a single edge point is sent in step 1206), or the visited network 100a sends multiple possible user plane edge points 308, 310 to the home network 100b in step 1206 (in that case the home network 100b selects the user plane edge point 308, 310).

(153) Step 1207

(154) This step is seen in FIG. 12a. This step is performed if there is an external PCRF 125. The dotted arrow indicates that this is an optional step. A PCEF initiated IP-CAN Session Establishment/Modification procedure takes place between the SM 303 in the home network 100b and the PCRF 125 in the home network 100b. If there is no external PCRF 125, this procedure in step 1207 is handled inside the SM 303.

(155) Step 1208

(156) This step is seen in FIG. 12a. The SM 303 in the home network 100b applies local policies.

(157) Step 1209

(158) This step is seen in FIG. 12a. The SM 303 in the home network 100b allocates an IP address for the UE 101. The IP address may be allocated using a local IP address pool.

(159) The allocation of the IP address may be coordinated with the IAP 310 in the home network 100b. The IP address which is allocated in step 1209 is the is the UE IP Address for this PDN Connection. This IP address may be referred to as an End User Address.

(160) Step 1210

(161) This step is seen in FIG. 12b. The SM 303 in the home network 100b sends a create chain request message to the MoSCC 305 in the home network 100b. The MoSCC 305 in the home network 100b creates the chain as requested.

(162) Step 1211

(163) This step is seen in FIG. 12b. The MoSCC 305 in the home network 100b sends instructions to the UPF 308 in the home network 100b to prepare to serve the UE 101. These instructions may be transmitted in a message which may be referred to as a create mobile service chain request message.

(164) The UPFs 308 are configured to serve this UE 101. The UE ID or UE IP address may be used as key. The egress, peer UPF 308 in the chain is configured to handle S8-U, IP Address and TEID information is sent back to the SM 303.

(165) Step 1212

(166) This step is seen in FIG. 12b. The UPF 308 in the home network 100b sends a confirmation to the MoSCC 305 in the home network 100b of that the UPF 308 is now prepared to serve the UE 101. The confirmation may be transmitted in a message which may be referred to as a create mobile service chain response message.

(167) Step 1213

(168) This step is seen in FIG. 12b. The MoSCC 305 in the home network 100b sends a Create Chain Response message to the SM 303 in the home network 100b. This response message is a response to the request message in step 1210. The response message comprises information which indicates that the chain has been created.

(169) Step 1214

(170) This step is seen in FIG. 12b. The SM 303 in the in the home network 100b sends a create session response message to the SM 303 in the visited network 100a. The response message is a response to the request message in step 1206 which is seen in FIG. 12a.

(171) Step 1215

(172) This step is seen in FIG. 12b. The SM 303 in the visited network 100a applies local policies.

(173) Step 1216

(174) Payload is transmitted to the UE 101 which roams into the visited network 100a. The payload is transmitted via the IAP 310 in the home network 100b, the UPF 308 in the home network 100b, the IAP 310 in the visited network, the UPF 308 in the visited network and the SM 303 in the visited network 100a before reaching the UE 101.

(175) Finding Uplink and Downlink User Plane Edge Points

(176) How to find that uplink user plane edge point (e.g. an entry point) can be performed in a similar way as in today's EPC architecture. 3GPP TS 23.401, V13.2.0, Chapter 4.3.8.1, regarding Roaming setup using the S8 interface reads:

(177) The PDN GW domain name shall be constructed and resolved by the method described in 3GPP TS 29.303, which takes into account any value received in the APN-OI Replacement field for home routed traffic. Otherwise, or when the resolution of the above PDN GW domain name fails, the PDN GW domain name shall be constructed by the serving node using the method specified in Annex A of 3GPP TS 23.060 and clause 9 of 3GPP TS 23.003. If the Domain Name Service function provides a list of PDN GW addresses, one PDN GW address is selected from this list. If the selected PDN GW cannot be used, e.g. due to an error, then another PDN GW is selected from the list. The specific interaction between the MME/SGSN and the Domain Name Service function may include functionality to allow for the retrieval or provision of additional information regarding the PDN GW capabilities (e.g. whether the PDN GW supports PMIP-based or GTP-based S5/S8, or both).

(178) With the above information the visited network 100a knows the PGW 113 address in the home network 100b and the Create Session Request procedure can be started.

(179) Finding the user plane edge point 308, 310 (e.g. the entry point) in the other direction; i.e. finding the IAP 310 in the visited network 100a by the home network 100b can be performed in a similar way. With the difference that, due to the anchorless concept, one out of many IAPs 310 can be chosen on a per-packet basis. This is different from the current EPC's PGW 113 selection mechanism where is PGW 113 is selected one upon PDN connection setup. Several options are possible: If the visited network 100a is aware that the home network 100b is based on MSC (see previous section), then it may inform in the Create Session Request which IAP 310, or set of IAP's 310, the home network 100b shall use for downlink traffic. If a set of IAP's 310 is provided, then the home network 100b may be allowed to pick any of those for downlink traffic. The selection may be made one, or may even be made on a per-packet basis just as in the basic mobile service chaining concept. If the visited network 100a is not aware of the home network 100b being based on MSC or not, then the Create Session Request sent by the VPLMN would be a Create Session Request as if the visited network 100a would be based on legacy EPC. In other words, the visited network 100a acts as if it would be legacy EPC. This brings us to scenario 2 in the next section.
Scenario 3: Home Network 100b is Based on MSC and Visited Network 100a is Legacy EPC

(180) What has not been described in the previous scenario is how the user plane traffic is carried between the home network 100b and the visited network 100a. Assuming that the visited network 100a in the previous scenario is legacy EPC. This brings us to scenario 2. In such scenario, the user plane traffic to/from the visited network 100a will be GTP-based. FIG. 13 shows an example of an initial attach for scenario 2. In FIG. 13, the visited network 100a which is a legacy EPC network comprises a SGW 110. The SGW 110 is an entity which needs to be visible for roaming cases and migration. The signaling flows are valid for a visiting UE 101 using a SGW 110 in the visited network 100a. FIG. 13 illustrates an example of a signaling flow for scenario 2 during an initial attach. The method exemplified in FIG. 12 comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(181) Step 1301

(182) The SGW 110 in the visited network 100a sends a create session request message to the SM 303 in the home network 100b.

(183) Step 1302

(184) This step corresponds to step 1207 in FIG. 12a. This step is performed if there is an external PCRF 125. The dotted arrow indicates that this is an optional step. A PCEF initiated IP-CAN Session Establishment/Modification procedure takes place between the SM 303 in the home network 100b and the PCRF 125 in the home network 100b. If there is no external PCRF 125, this procedure in step 1302 is handled inside the SM 303.

(185) Step 1303

(186) This step corresponds to step 1208 in FIG. 12a. The SM 303 in the home network 100b applies local policies.

(187) Step 1304

(188) This step corresponds to step 1209 in FIG. 12a. The SM 303 in the home network 100b allocates an IP address. The IP address may be allocated using a local IP address pool. The allocation of the IP address may be coordinated with the IAP 310 in the home network 100b.

(189) Step 1305

(190) This step corresponds to step 1210 in FIG. 12b. The SM 303 in the home network 100b sends a create chain request message to the MoSCC 305 in the home network 100b. The MoSCC 305 in the home network 100b creates the chain as requested.

(191) Step 1306

(192) This step corresponds to step 1211 in FIG. 12b. The MoSCC 305 in the home network 100b sends instructions to the UPF 308 in the home network 100b to prepare to serve the UE 101. These instructions may be transmitted in a message which may be referred to as a create mobile service chain request message.

(193) The UPFs 308 are configured to serve this UE 101. The UE ID or UE IP address may be used as key. The egress, peer UPF 308 in the chain is configured to handle S8-U, IP Address and TEID information is sent back to the SM 303.

(194) Step 1307

(195) This step corresponds to step 1212 in FIG. 12b. The UPF 308 in the home network 100b sends a confirmation to the MoSCC 305 in the home network 100b of that the UPF 308 is now prepared to serve the UE 101. The confirmation may be transmitted in a message which may be referred to as a create mobile service chain response message.

(196) Step 1308

(197) This step corresponds to step 1213 in FIG. 12b. The MoSCC 305 in the home network 100b sends a Create Chain Response message to the SM 303 in the home network 100b. This response message is a response to the request message in step 1305. The response message comprises information which indicates that the chain has been created.

(198) Step 1309

(199) The SM 303 in the home network 100b sends a create session response message to the SGW 110 in the visited network 100a. This response message is a response to the request message in step 1301.

(200) Step 1310

(201) Downlink payload is sent via the IAP 310 and UPFs 308 in the home network 100b to the SGW 110 in the visited network 100a for further transmission to the UE 101 which visits the visited network 100a.

(202) Note that one of the UPFs 308 in FIG. 13 need to cater for the GTP communication (similar to S8-U). In the uplink, a UPF 308 in the home network 100b may need to convert the incoming GTP-U packets to an encapsulation for MSC. This can be performed by a special UPF 380 dedicated for this purpose. This UPF 308 may be denoted as the CL-UL in FIGS. 7 and 11. The converter and the CL may be the same UPF or they may be different UPFs. The task of this classifier may be to strip the GTP-U header from the incoming packet, to classify the packet, such that a new service-chaining header can be added to the packet. FIG. 14 illustrates an example of the re-mapping of a BS-ID TAG to a GTP unique identifier. The payload enters the IAP 310 in the home network 100b which is based on MSC. The IAP 310 in the home network 100b applies a BS-ID tag (e.g. xxx.yyy.zzz) to the payload. The BS-ID tag (e.g. xxx.yyy.zzz) may be seen as a MSC specific tag. The BS-ID tag (e.g. xxx.yyy.zzz) is transmitted to the UPF 308 in the home network 100b. The packet arrives in the GTP UPF in the home network (step 1401). The IP-CAN Session (e.g. 1.2.3.4) is defined by the GTP UPF (step 1402). The GTP-TEID (e.g. 12345678) is retrieved by the GTP UPF (step 1403). The GTP-TEID may be allocated during the Create Session Procedure. The packet is forwarded from the GTP UPF in the home network 100b to the IAP or SGW 110 in the visited network 100a (step 1404). The packet is identified by the GTP UPF IP address (e.g. 1.2.3.4) and the unique GTP-TEID (e.g. 12345678).

(203) Similarly, in the downlink, a UPF 308 in the home network 100b may need to convert outgoing packets to GTP-U packets.

(204) FIG. 15 illustrates an example of an initial attach where the visited network 100a is based on MSC and the home network 100b is a legacy EPC network, i.e. scenario 1. The signaling flow in FIG. 15 is valid for a visitor using a PGW function in its home network 100b. The method exemplified in FIG. 15 comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(205) Step 1501

(206) This step corresponds to step 1201 in FIG. 12a. The SM 303 in the visited network 100a applies local policies.

(207) Step 1502

(208) This step corresponds to step 1202 in FIG. 12b. The SM 303 in the home network 100b sends a create chain request message to the MoSCC 305 in the home network 100b. The MoSCC 305 in the home network 100b creates the chain as requested.

(209) Step 1503

(210) This step corresponds to step 1203 in FIG. 12a. The MoSCC 305 in the home network 100b sends instructions to the UPF 308 in the home network 100b to prepare to serve the UE 101. These instructions may be transmitted in a message which may be referred to as a create mobile service chain request message. Similar to as described in step 902 in FIG. 9 and step 1203 in FIG. 12a, the MoSCC 305 may also send a user plane edge point setup request message (not illustrated in FIG. 15).

(211) The UPFs 308 are configured to serve this UE 101. The UE ID or UE IP address may be used as key. The egress, peer UPF 308 in the chain is configured to handle S8-U, IP Address and TEID information is sent back to the SM 303.

(212) Step 1504

(213) This step corresponds to step 1204 in FIG. 12a. The UPF 308 in the home network 100b sends a confirmation to the MoSCC 305 in the home network 100b of that the UPF 308 is now prepared to serve the UE 101. The confirmation may be transmitted in a message which may be referred to as a create mobile service chain response message. Similar to as described in step 903 in FIG. 9 and step 1204 in FIG. 12a, the MoSCC 305 may also send a user plane edge point setup response message (not illustrated in FIG. 15).

(214) Step 1505

(215) This step corresponds to step 1205 in FIG. 12b. The MoSCC 305 in the home network 100b sends a Create Chain Response message to the SM 303 in the home network 100b. This response message is a response to the request message in step 1502. The response message comprises information which indicates that the chain has been created.

(216) Step 1506

(217) The SM 303 in the visited network 100a sends a create session request message to the PGW 113 in the home network 100b.

(218) Step 1507

(219) PGW 113 in the home network 100b creates the requested session and allocates an IP address. The IP address may be allocated using a local IP address pool. The allocation of the IP address may be coordinated with the IAP 310 in the visited network 100a.

(220) Step 1508

(221) The SM 303 in the visited network 100a sends a create session response message to the PGW 113 in the home network 100b. This response message is a response to the request message in step 1506.

(222) Step 1509

(223) The PGW 113 in the home network 100b may send the payload to SM 303 in the visited network via the IAP 310 and the UPF 308 in the visited network 100a.

(224) This scenario 3 is the opposite of scenario 2. In the uplink, a UPF 308 in the visited network 100a will need to convert the outgoing packets to GTP-U packets. In the downlink, a UPF 308 in the visited network 100a needs to be able to receive GTP-U packets and convert them to an encapsulation for MSC. The same solution as described in the previous scenario 2 can be re-used here.

(225) The method described above will now be described seen from the perspective of the control plane node 303. FIG. 16 is a flowchart describing the present method performed by the control plane node 303 for handling a UE 101 which roams into a visited network 100a. The control plane node 303 is comprised in the visited network 100a or in a home network 100b. At least the network in which the control plane node 303 is comprised is a MSC network. The visited network 100a may comprise a SGW when the visited network 100a is a 3GPP EPC network and when the home network 100b is a MSC network and comprises the control plane node 303. The home network 100b may comprise a PGW when the home network 100b is a 3GPP EPC network and when the visited network 100a is a MSC network and comprises the control plane node 303. The visited network 100a may be a MSC network and the home network 100b may be a 3GPP EPC network, or the visited network 100a may be the 3GPP EPC network and the home network 100b may be the MSC network, or both the visited network 100a and the home network 100b may be MSC networks.

(226) The method exemplified in FIG. 16 comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(227) Step 1601

(228) This step corresponds to step 901 in FIG. 9, step 1201 in FIG. 12a, step 1210 in FIG. 12b, step 1305 in FIG. 13 and step 1502 in FIG. 15. When the UE 101 roams into the visited network 100a, the control plane node 303 transmits a create chain request message to a service chain controller 305. The create chain request message is a request to create a chain of UPF nodes 308 that user plane packets to or from the UE 101 should traverse. The create chain request message comprises an identity of the UE 101. The control plane node 303 may comprise information about which type the home network 100b is. The type of the home network 100b may be MSC or 3GPP EPC.

(229) Step 1602

(230) This step corresponds to step 904 in FIG. 9, step 1205 in FIG. 12a, step 1213 in FIG. 12b, step 1308 in FIG. 13 and step 1505 in FIG. 15. The control plane node 303 receives a create chain response message from the service chain controller 305. The create chain response message indicates that the requested chain has been created. The create chain response message comprises information which indicates at least one of an address and an identifier of a user plane edge point 308, 310 in the network in which the control plane node 303 is comprised and which the user plane packets should travers in the created chain. The address of the user plane edge point 308, 310 may be an IP address and the identifier is a TEID.

(231) Step 1603

(232) This step corresponds to step 1206 in FIG. 12a and step 1506 in FIG. 15. The control plane node 303 may transmit a create session request message to the network which the control plane node 303 is not comprised in. The create session request message comprises at least one of the address and identifier of the user plane edge point 308, 310.

(233) The create session request message may be GTP based if the control plane node 303 knows that either the visited network 100a or the home network 100b are 3GPP EPC networks.

(234) The create session request message may comprise information indicating an user plane edge point 308, 310 which the home network 100b shall use for downlink traffic to the UE 101 when the visited network 100a knows that the home network 100b is a MSC network.

(235) The create session request message may be based on 3GPP EPC when the visited network 100a is unaware of which type the home network 100b is.

(236) Step 1604

(237) This step corresponds to step 1214 in FIG. 12b and step 1508 in FIG. 15. The control plane node 303 may receive a create session response message from the network which the control plane node 303 is not comprised in.

(238) Step 1605

(239) This step corresponds to step 1206 in FIG. 12a and step 1301 in FIG. 13. The control plane node 303 may receive a create session request message from the network which the control plane node 303 is not comprised in.

(240) The create session request message may be GTP based if the control plane node 303 knows that either the visited network 100a or the home network 100b are 3GPP EPC networks.

(241) The create session request message may comprise information indicating an user plane edge point 308, 310 which the home network 100b shall use for downlink traffic to the UE 101 when the visited network 100a knows that the home network 100b is a MSC network.

(242) The create session request message may be based on 3GPP EPC when the visited network 100a is unaware of which type the home network 100b is.

(243) Step 1606

(244) This step corresponds to step 1214 in FIG. 12b and step 1309 in FIG. 13. The control plane node 303 may transmit a create session response message to the network which the control plane node 303 is not comprised in.

(245) Step 1607

(246) When the control plane node 303 is comprised in the visited network 100a which is a MSC network, the control plane node 303 may select the user plane edge point 308, 310 in the visited network 100a from a plurality of possible user plane edge points 308, 310.

(247) Step 1608

(248) When the control plane node 303 is comprised in the visited network 100a which is a MSC network and the home network 100b is also a MSC network, the control plane node 303 may transmit information indicating a plurality of possible user plane edge points 308, 310 in the visited network 100a to the home network 100b for selection of the user plane edge point 308, 310.

(249) Step 1609

(250) This step corresponds to step 1007 in FIG. 10. When the control plane node 303 is comprised in the home network 100b which is a MSC network, the control plane node 303 may transmit an update location ID request message to an address advertisement node 310. The update location ID request message comprises information indicating at least one of a user plane edge point of the visited network 100a and a user plane edge point of the home network 100b.

(251) Step 1610

(252) This step corresponds to step 1008 in FIG. 10. This step is performed after step 1609. The control plane node 303 may receive an update location ID response message from the address advertisement node 310.

(253) Step 1611

(254) This step corresponds to step 1209 in FIG. 12a and step 1304 in FIG. 13. When the control plane node 303 is comprised in the home network 100b, the control plane node 303 may allocate an address to the UE 101. The allocation of the address may be coordinated with an address advertisement node 310.

(255) To perform the method steps shown in FIG. 16 for handling a UE 101, which roams into a visited network 100a, the control plane node 303 comprises an arrangement as shown in FIG. 17.

(256) To perform the method steps shown in FIG. 17 for handling a UE 101, which roams into a visited network 100a, the control plane node 303 is adapted to, e.g. by means of a first transmitting module 1701, transmit a create chain request message to a service chain controller 305 when the UE 101 roams into the visited network 100a. The create chain request message is a request to create a chain of UPF nodes 308 that user plane packets to or from the UE 101 should traverse. The create chain request message comprises an identity of the UE 101. The first transmitting module 1701 may also be referred to as a first transmitting unit, a first transmitting means, a first transmitting circuit, first means for transmitting, first output unit etc. The first transmitting module 1701 may be a transmitter, a transceiver etc. The first transmitting module 1701 may be a wireless transmitter of the control plane node 303 of a wireless or fixed communications system.

(257) The control plane node 303 is adapted to, e.g. by means of a first receiving module 1703, receive a create chain response message from the service chain controller 305. The create chain response message indicates that the requested chain has been created. The create chain response message comprises information which indicates at least one of an address and an identifier of a user plane edge point 308, 310 in the network in which the control plane node 303 is comprised and which the user plane packets should travers in the created chain. The first receiving module 1703 may also be referred to as a first receiving unit, a first receiving means, a first receiving circuit, first means for receiving, first input unit etc. The first receiving module 1703 may be a receiver, a transceiver etc. The first receiving module 1703 may be a wireless receiver of the control plane node 303 of a wireless or fixed communications system.

(258) The control plane node 303 may be adapted to, e.g. by means of the first transmitting module 1701, transmit a create session request message to the network which the control plane node 303 is not comprised in. The create session request message may comprise at least one of the address and identifier of the user plane edge point 308, 310. The address of the user plane edge point 308, 310 may be an IP address and the identifier is a TEID. The create session request message may be GTP based if the control plane node 303 knows that either the visited network 100a or the home network 100b are 3GPP EPC networks. The create session request message may comprise information indicating an user plane edge point 308, 310 which the home network 100b shall use for downlink traffic to the UE 101 when the visited network 100a knows that the home network 100b is a MSC network. The create session request message may be based on 3GPP EPC when the visited network 100a is unaware of which type the home network 100b is.

(259) The control plane node 303 may be adapted to, e.g. by means of the first receiving module 1703, receive a create session response message from the network which the control plane node 303 is not comprised in.

(260) The control plane node 303 may be adapted to, e.g. by means of the first receiving module 1703, receive a create session request message from the network which the control plane node 303 is not comprised in.

(261) The control plane node 303 may be adapted to, e.g. by means of the first transmitting module 1701, transmit a create session response message to the network which the control plane node 303 is not comprised in.

(262) When the control plane node 303 is comprised in the visited network 100a which is a MSC network, the control plane node 303 may be further adapted to, e.g. by means of a first selecting module 1705, select the user plane edge point 308, 310 in the visited network 100a from a plurality of possible user plane edge points 308, 310. The first selecting module 1705 may also be referred to as a first selecting unit, a first selecting means, a first selecting circuit, first means for selecting etc. The first selecting module 1705 may be a first processor 1707 of the control plane node 303.

(263) When the control plane node 303 is comprised in the visited network 100a which is a MSC network and the home network 100b is also a MSC network, the control plane node 303 may be further adapted to, e.g. by means of the first transmitting module 1701, transmit information indicating a plurality of possible user plane edge points 308, 310 in the visited network 100a to the home network 100b for selection of the user plane edge point 308, 310.

(264) When the control plane node 303 is comprised in the home network 100b which is a MSC network, the control plane node 303 may be further adapted to, e.g. by means of the first transmitting module 1701, transmit an update location ID request message to an address advertisement node 310. The update location ID request message may comprise information indicating at least one of an edge point of the visited network 100a and an edge point of the home network 100b.

(265) The control plane node 303 may be further adapted to, e.g. by means of the first receiving module 1703, receive an update location ID response message from the address advertisement node 310.

(266) The control plane node 303 may be adapted to, e.g. by means of a first allocating module 1710, allocate an address to the UE 101 when the control plane node 303 is comprised in the home network 100b. The allocation of the address may be coordinated with an address advertisement node 310. The first allocating module 1710 may also be referred to as a first allocating unit, a first allocating means, a first allocating circuit, first means for allocating etc. The first allocating module 1710 may be the first processor 1707 of the control plane node 303.

(267) The control plane node 303 may comprise information about which type the home network 100b. The type of the home network 100b may be MSC or 3GPP EPC.

(268) The visited network 100a may comprise a SGW when the visited network 100a is a 3GPP EPC network and when the home network 100b is a MSC network and comprises the control plane node 303. The home network 100b may comprise a PGW when the home network 100b is a 3GPP EPC network and when the visited network 100a is a MSC network and comprises the control plane node 303. The visited network 100a may be a MSC network and the home network 100b may be a 3GPP EPC network, or the visited network 100a may be the 3GPP EPC network and the home network 100b may be the MSC network, or both the visited network 100a and the home network 100b may be MSC networks.

(269) The control plane node 303 may further comprise a first memory 1715 comprising one or more memory units. The memory 1715 is arranged to be used to store data, received data streams, power level measurements, request messages, response messages, information about created chains, information which identifies a user plane edge point, location ID, threshold values, time periods, information about type of network (e.g. MSC or 3GPP EPC), configurations, schedulings, and applications to perform the methods herein when being executed in the control plane node 303. The first memory 1715 comprises instructions executable by the first processor 1707.

(270) Those skilled in the art will also appreciate that the first transmitting module 1701, the first receiving module 1703, the first selecting module 1705 and the first allocating module 1710 described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in a memory, that when executed by the one or more processors such as the first processor 1707 perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

(271) In some embodiments, a first computer program may comprise instructions which, when executed on at least one processor (e.g. the first processor 1707), cause the at least one processor to carry out the method steps in FIG. 16. A first carrier may comprise the first computer program, and the first carrier is one of an electronic signal, optical signal, radio signal or computer readable storage medium.

(272) The method described above will now be described seen from the perspective of the service chain controller 305. FIG. 18 is a flowchart describing the present method performed by the service chain controller 305 for handling a UE 101 which roams into a visited network 100a. The service chain controller 305 is comprised in the visited network 100a or in the home network 100b. At least the network in which the service chain controller 305 is comprised is a MSC network. The method exemplified in FIG. 18 comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(273) Step 1801

(274) This step corresponds to step 901 in FIG. 9, step 1201 in FIG. 12a, step 1210 in FIG. 12b, step 1305 in FIG. 13 and step 1502 in FIG. 15. When the UE 101 roams into the visited network 100a, the service chain controller 305 receives a create chain request message from a control plane node 303. The create chain request message is a request to create a chain of UPF nodes 308 that user plane packets to or from the UE 101 should traverse. The create chain request message comprises an identity of the UE 101.

(275) Step 1802

(276) The service chain controller 305 creates the requested chain of UPF nodes 308.

(277) Step 1803

(278) The service chain controller 305 determines a user plane edge point 308, 310 in the network which the control plane node 303 is comprised and which the user plane packets should travers.

(279) Step 1804

(280) This step corresponds to step 902 in FIG. 9, step 1203 in FIG. 12a, step 1211 in FIG. 12b, step 1306 in FIG. 13 and step 1503 in FIG. 15. The service chain controller 305 transmits, to the determined user plane edge point 308, 310, instructions to prepare to serve the UE 101 and the identity of the UE 101.

(281) Step 1805

(282) This step corresponds to step 903 in FIG. 9, step 1204 in FIG. 12a, step 1212 in FIG. 12b, step 1307 in FIG. 13 and step 1504 in FIG. 15. The service chain controller 305 receives, from the user plane edge point 308, 310, a confirmation of that the user plane edge point 308, 310 in the chain is prepared to serve the UE 101 and information indicating at least one of an address and identifier of the user plane edge point 308, 310 in the network which the control plane node 303 is comprised and which the user plane packets should travers.

(283) Step 1806

(284) This step corresponds to step 904 in FIG. 9, step 1205 in FIG. 12a, step 1213 in FIG. 12b, step 1308 in FIG. 13 and step 1505 in FIG. 15. The service chain controller 305 transmits a create chain response message to the control plane node 303. The create chain response message indicates that the requested chain has been created. The create chain response message comprises information which indicates the at least one of the address and identifier of the user plane edge point 308, 310 in the network in which the control plane node 303 is comprised and which the user plane packets should travers in the created chain.

(285) The visited network 100a may comprise a SGW when the visited network 100a is a 3GPP EPC network and when the home network 100b is a MSC network and comprises the control plane node 303. The home network 100b may comprise a PGW when the home network 100b is a 3GPP EPC network and when the visited network 100a is a MSC network and comprises the control plane node 303. The visited network 100a may be a MSC network and the home network 100b may be a 3GPP EPC, network, or the visited network 100a may be the 3GPP EPC network and the home network 100b may be the MSC network, or both the visited network 100a and the home network 100b may be MSC networks.

(286) To perform the method steps shown in FIG. 18 for handling a UE 101, which roams into a visited network 100a, the service chain controller 305 comprises an arrangement as shown in FIG. 19. The service chain controller 305 is comprised in the visited network 100a or in a home network 100b. At least the network in which the service chain controller 305 is comprised is a MSC network.

(287) To perform the method steps shown in FIG. 17 for handling a UE 101, which roams into a visited network 100a, the service chain controller 305 is adapted to, e.g. by means of a second receiving module 1901, when the UE 101 roams into the visited network 100a, receive a create chain request message from a control plane node 303. The create chain request message is a request to create a chain of UPF nodes 308 that user plane packets to or from the UE 101 should traverse and wherein the create chain request message comprises an identity of the UE 101. The second receiving module 1901 may also be referred to as a second receiving unit, a second receiving means, a second receiving circuit, second means for receiving, first input unit etc. The second receiving module 1901 may be a receiver, a transceiver etc. The second receiving module 1901 may be a wireless receiver of the service chain controller 305 of a wireless or fixed communications system.

(288) The service chain controller 305 is adapted to, e.g. by means of a second creating module 1904, create the requested chain of UPF nodes 308. The second creating module 1904 may be a second processor 1907 of the service chain controller 305. The second creating module 1904 may also be referred to as a second creating unit, a second creating means, a second creating circuit, second means for creating etc. The second creating module 1904 may be a second processor 1907 of the service chain controller 305.

(289) The service chain controller 305 is adapted to, e.g. by means of a second determining module 1910, determine a user plane edge point 308, 310 in the network which the control plane node 303 is comprised and which the user plane packets should travers.

(290) The second determining module 1910 may also be referred to as a second determining unit, a second determining means, a second determining circuit, second means for determining etc. The second determining module 1910 may be the second processor 1907 of the service chain controller 305.

(291) The service chain controller 305 is adapted to, e.g. by means of a second transmitting module 1913, transmit, to the determined user plane edge point 308, 310, instructions to prepare to serve the UE 101 and the identity of the UE 101. The second transmitting module 1913 may also be referred to as a second transmitting unit, a second transmitting means, a second transmitting circuit, second means for transmitting, second output unit etc. The second transmitting module 1913 may be a transmitter, a transceiver etc. The second transmitting module 1913 may be a wireless transmitter of the service chain controller 305 of a wireless or fixed communications system.

(292) The service chain controller 305 is adapted to, e.g. by means of the second receiving module 1901, receive, from the user plane edge point 308, 310, a confirmation of that the user plane edge point 308, 310 in the chain is prepared to serve the UE 101 and information indicating at least one of an address and identifier of the user plane edge point 308, 310 in the network which the control plane node 303 is comprised and which the user plane packets should travers; and to The service chain controller 305 is adapted to, e.g. by means of the second transmitting module 1913, transmit a create chain response message to the control plane node 303. The create chain response message indicates that the requested chain has been created. The create chain response message comprises information which indicates the at least one of the address and identifier of the user plane edge point 308, 310 in the network in which the control plane node 303 is comprised and which the user plane packets should travers in the created chain.

(293) The visited network 100a may comprise a SGW when the visited network 100a is a 3GPP EPC network and when the home network 100b is a MSC network and comprises the control plane node 303. The home network 100b may comprise a PGW when the home network 100b is a 3GPP EPC network and when the visited network 100a is a MSC network and comprises the control plane node 303. The visited network 100a may be a MSC network and the home network 100b may be a 3GPP EPC network, or the visited network 100a may be the 3GPP EPC network and the home network 100b may be the MSC network, or both the visited network 100a and the home network 100b may be MSC networks.

(294) The service chain controller 305 may further comprise a second memory 1915 comprising one or more memory units. The second memory 1915 is arranged to be used to store data, received data streams, power level measurements, request messages, response messages, information about created chains, information which identifies a user plane edge point, location ID, threshold values, time periods, information about type of network (e.g. MSC or 3GPP EPC), configurations, schedulings, and applications to perform the methods herein when being executed in the service chain controller 305. The second memory 1915 comprises instructions executable by the second processor 1907.

(295) Those skilled in the art will also appreciate that the second receiving module 1901, the second creating module 1904, the second determining module 1910 and the second transmitting module 1913 described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in a memory, that when executed by the one or more processors such as the second processor 1907 perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single ASIC, or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a SoC.

(296) In some embodiments, a second computer program may comprise instructions which, when executed on at least one processor (e.g. the second processor 1907), cause the at least one processor to carry out the method steps in FIG. 18. A second carrier may comprise the second computer program, and the second carrier is one of an electronic signal, optical signal, radio signal or computer readable storage medium.

(297) The method described above will now be described seen from the perspective of the user plane edge point 308, 310. FIG. 20 is a flowchart describing the present method performed by the user plane edge point 308, 310 for handling a UE 101 which roams into a visited network 100a. The user plane edge point 308, 310 is comprised in the visited network 100a or in a home network 100b. At least the network in which the user plane edge point 308, 310 is comprised is a MSC network. The user plane edge point 308, 310 may be an address advertisement node 310 or a UPF node 308. The address advertisement node 310 may be an IAP or an IAP. The method exemplified in FIG. 20 comprises at least some of the following steps, which steps may be performed in any suitable order than described below:

(298) Step 2001

(299) This step corresponds to step 902 in FIG. 9, step 1203 in FIG. 12a, step 1211 in FIG. 12b, step 1306 in FIG. 13 and step 1503 in FIG. 15. The user plane edge point 308, 310 receives, from a service chain controller 305, instructions to prepare to serve the UE 101. The instructions comprise the identity of the UE 101.

(300) Step 2002

(301) This step corresponds to step 903 in FIG. 9, step 1204 in FIG. 12a, step 1212 in FIG. 12b, step 1307 in FIG. 13 and step 1504 in FIG. 15. The user plane edge point 308, 310 transmits, to the service chain controller 305, a confirmation of that the user plane edge point 308, 310 is prepared to serve the UE 101 and information indicating at least one of an address and identifier of the user plane edge point 308, 310 in the visited network 100a which the user plane packets should travers.

(302) Step 2003

(303) This step corresponds to steps 1402, 1403 and 1404 in FIG. 14. The user plane edge point 308, 310 may be comprised in the home network 100b which is a MSC network. The user plane edge point 308, 310 may convert a GTP-U uplink packet to an MSC user plane uplink packet.

(304) Step 2004

(305) This step corresponds to steps 1402, 1403 and 1404 in FIG. 14. The user plane edge point 308, 310 may be comprised in the home network 100b which is a MSC network. The user plane edge point 308, 310 may convert a MSC user plane downlink packet to a GTP-U downlink packet.

(306) Step 2005

(307) This step corresponds to steps 1402, 1403 and 1404 in FIG. 14. The user plane edge point 308, 310 may be comprised in the visited network 100a which is a MSC network. The user plane edge point 308, 310 may convert a MSC user plane uplink packet to a GTP-U uplink packet.

(308) Step 2006

(309) This step corresponds to steps 1402, 1403 and 1404 in FIG. 14. The user plane edge point 308, 310 may be comprised in the visited network 100a which is a MSC network. The user plane edge point 308, 310 may convert a GTP-U downlink packet to an MSC user plane downlink packet.

(310) To perform the method steps shown in FIG. 20 for handling a UE 101, which roams into a visited network 100a, the user plane edge point 308, 310 comprises an arrangement as shown in FIG. 21. The user plane edge point 308, 310 is comprised in the visited network 100a or in a home network 100b. At least the network in which the user plane edge point 308, 310 is comprised is a MSC network. The user plane edge point 308, 310 may be an address advertisement node 310 or a UPF node 308.

(311) To perform the method steps shown in FIG. 20 for handling a UE 101, which roams into a visited network 100a, the user plane edge point 308, 310 is adapted to, e.g. by a third receiving module 2101, receive from a service chain controller 305, instructions to prepare to serve the UE 101. The instructions comprise the identity of the UE 101. The third receiving module 2101 may also be referred to as a third receiving unit, a third receiving means, a third receiving circuit, third means for receiving, third input unit etc. The third receiving module 2101 may be a receiver, a transceiver etc. The third receiving module 2101 may be a wireless receiver of the user plane edge point 308, 310 of a wireless or fixed communications system.

(312) The user plane edge point 308, 310 is adapted to, e.g. by means of a third transmitting module 2103, transmit, to the service chain controller 305, a confirmation of that the user plane edge point 308, 310 is prepared to serve the UE 101 and information indicating at least one of an address and identifier of the user plane edge point 308, 310 in the visited network 100a which the user plane packets should travers. The third transmitting module 2103 may also be referred to as a third transmitting unit, a third transmitting means, a third transmitting circuit, third means for transmitting, third output unit etc. The third transmitting module 2103 may be a transmitter, a transceiver etc. The third transmitting module 2103 may be a wireless transmitter of the user plane edge point 308, 310 of a wireless or fixed communications system.

(313) The user plane edge point 308, 310 may be comprised in the home network 100b which is a MSC network. The user plane edge point 308, 310 may be further adapted to, e.g. by means of a third converting module 2105, convert a GTP-U uplink packet to an MSC user plane uplink packet. The third converting module 2105 may also be referred to as a third converting unit, a third converting means, a third converting circuit, third means for converting etc. The third converting module 2105 may be a third processor 2108 of the user plane edge point 308, 310.

(314) The user plane edge point 308, 310 may be adapted to, e.g. by means of the third converting module 2105, convert a MSC user plane downlink packet to a GTP-U downlink packet.

(315) The user plane edge point 308, 310 may be comprised in the visited network 100a which is a MSC network. The user plane edge point 308, 310 may be adapted to, e.g. by means of the third converting module 2105, convert a MSC user plane uplink packet to a GTP-U, uplink packet. The user plane edge point 308, 310 may be adapted to, e.g. by means of the third converting module 2105, convert a GTP-U downlink packet to an MSC user plane downlink packet.

(316) The user plane edge point 308, 310 may further comprise a third memory 2110 comprising one or more memory units. The third memory 2110 is arranged to be used to store data, received data streams, power level measurements, request messages, response messages, information about created chains, information which identifies a user plane edge point, location ID, threshold values, time periods, information about type of network (e.g. MSC or 3GPP EPC), configurations, schedulings, and applications to perform the methods herein when being executed in the user plane edge point 308, 310. The third memory 2108 comprises instructions executable by the third processor 2108.

(317) Those skilled in the art will also appreciate that the third receiving module 2101, the third transmitting module 2103 and the third converting module 2105 described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in a memory, that when executed by the one or more processors such as the third processor 2108 perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single ASIC, or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a SoC.

(318) In some embodiments, a third computer program may comprise instructions which, when executed on at least one processor (e.g. the third processor 2108), cause the at least one processor to carry out the method steps in FIG. 20. A third carrier may comprise the third computer program, and the third carrier is one of an electronic signal, optical signal, radio signal or computer readable storage medium.

(319) The present mechanism for handling a UE 101 which roams into a visited network 100a may be implemented through one or more processors, such as a first processor 1707 in the control plane node arrangement depicted in FIG. 17, a second processor 1907 in the service chain controller arrangement in FIG. 19 and a third processor 2108 in the user plane edge point arrangement depicted in FIG. 21, together with computer program code for performing the functions of the embodiments herein. The processor may be for example a Digital Signal Processor (DSP), ASIC processor, Field-programmable gate array (FPGA) processor or micro processor. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into at least one of the control plane node 303, the service chain controller 305 and the user plane edge point 308, 310. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code can furthermore be provided as pure program code on a server and downloaded to at least one of the control plane node 303, the service chain controller 305 and the user plane edge point 308, 310.

(320) The embodiments herein are not limited to the above described embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be taken as limiting the scope of the embodiments, which is defined by the appending claims.

(321) It should be emphasized that the term comprises/comprising when used in this specification is taken to specify the presence of stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. It should also be noted that the words a or an preceding an element do not exclude the presence of a plurality of such elements.

(322) The term configured to used herein may also be referred to as arranged to, adapted to, capable of or operative to.

(323) It should also be emphasized that the steps of the methods defined in the appended claims may, without departing from the embodiments herein, be performed in another order than the order in which they appear in the claims.