Sx protocol extension to support node PDR

1. A method performed by a first network node configured as control plane function (CPF), the first network node is coupled, via an Sx interface, to a second network node configured as user plane function (UPF), the method comprising:

transmitting a request message associated with a Packet Detection Rule (PDR) to the second network node via the Sx interface, wherein

the PDR is applicable to more than one Sx session,

the request message includes an information element (IE),

the IE contains indication information indicating that the PDR is applicable to the more than one Sx session,

the indication information includes a group session identifier identifying two or more Sx sessions to which the PDR is applicable or the indication information indicates that the PDR is applicable to all Sx sessions associated with the second network node; and

receiving a response message, from the second network node, indicating whether the transmitted request message is accepted or not by the second network node for applying the PDR.

2. The method according to claim 1 , wherein the PDR is a node PDR, and the request message is an Sx node PDR management request message.

3. The method according to claim 2 , wherein the Sx node PDR management request message indicates at least one of:

a node PDR is to be added;

an information element (IE) of a node PDR is to be modified; and

a node PDR is to be removed.

4. The method according to claim 2 , wherein the node PDR includes a node PDR identifier IE

identifying the node PDR.

5. The method according to claim 4 , wherein the indication information includes the flag indicating that PDR is applicable to all Sx sessions associated with the second network node.

6. The method according to claim 4 , wherein the first network node transmits the Sx node PDR management request message associated with the node PDR in any one or more of the following procedures:

a node PDR management request procedure, to indicate to which Sx sessions the node PDR is applicable;

a session establishment request procedure, to indicate if the Sx session to be established is included in said two or more Sx sessions identified by the group session identifier; and

Sx session modification request procedure, to indicate a modification of the group session identifier of the node PDR applicable to the Sx session to be modified.

7. The method according to claim 2 , wherein the node PDR includes:

a precedence IE identifying a precedence of the node PDR.

8. A method performed by a second network node configured as user plane function (UPF), the second network node is coupled, via an Sx interface, to a first network node configured as control plane function (CPF), the method comprising:

receiving a message associated with a first Packet Detection Rule (PDR) from the first network node via the Sx interface, wherein

the first PDR is applicable to more than one Sx session,

the message includes an information element (IE),

the IE contains indication information indicating that the first PDR is applicable to more than one Sx session, and

the indication information includes a group session identifier identifying two or more Sx sessions to which the first PDR is applicable or the indication information indicates that first PDR is applicable to all Sx sessions associated with the second network node, and

said two or more Sx sessions include a first Sx session;

receiving a packet;

performing Sx session look-up to identify an Sx session to which the received packet corresponds, wherein the identified Sx session is the first Sx session;

determining that a group of one or more PDRs is applicable to the first Sx session, wherein the group of one or more PDRs includes the first PDR; and

applying the first PDR.

9. The method according to claim 8 , wherein the first PDR is a node PDR, and the message is an Sx node PDR management request message.

10. The method according to claim 9 , wherein the method further comprising:

according to the Sx node PDR management request message, performing at least one of:

adding a node PDR;

modifying an information element (IE) of a node PDR; and

removing a node PDR.

11. The method according to claim 9 , wherein the node PDR includes a node PDR identifier

identifying the node PDR.

12. The method according to claim 11 , wherein the indication information includes the flag indicating that first PDR is applicable to all Sx sessions associated with the second network node.

13. The method according to claim 9 , wherein the node PDR includes:

a precedence IE identifying a precedence of the node PDR.

14. The method according to claim 9 , the method further comprising:

selecting from the group of one or more PDRs the first PDR matching to the received packet together with a session level PDR in decreasing order of precedence, wherein the session level PDR includes IE identifying an Sx session.

15. The method according to claim 14 , wherein the precedence of each of the one or more PDRs is higher than the precedence of the session level PDR.

16. The method according to claim 9 , the method further comprising:

transmitting to the first network node an Sx node PDR management response message indicating whether the Sx node PDR management request message is accepted or rejected.

17. A first network node configured as control plane function (CPF), the first network node is coupled, via an Sx interface, to a second network node configured as user plane function (UPF), the first network node comprising:

at least one processor; and

a non-transitory computer readable medium coupled to the at least one processor, the non-transitory computer readable medium storing instructions executable by the at least one processor, whereby the first network node is configured to:

transmit a message associated with a Packet Detection Rule (PDR) to the second network node via the Sx interface, wherein

the PDR is applicable to more than one Sx session,

the message includes an information element (IE),

the IE contains indication information indicating that the PDR is applicable to the more than one Sx session, and

the indication information includes a group session identifier identifying two or more Sx sessions to which the PDR is applicable or the indication information indicates that the PDR is applicable to all Sx sessions associated with the second network node, and

the first network node is further configured to receive a response message, from the second network node, indicating whether the transmitted message is accepted or not by the second network node for applying the PDR.

18. A second network node configured as user plane function (UPF), the second network node is coupled, via an Sx interface, to a first network node configured as control plane function (CPF), the second network node comprising:

at least one processor; and

a non-transitory computer readable medium coupled to the at least one processor, the non-transitory computer readable medium storing instructions executable by the at least one processor, whereby the second network node is configured to:

receive a message associated with a first Packet Detection Rule (PDR) from the first network node via the Sx interface, wherein

the first PDR is applicable to more than one Sx session,

the message includes an information element (IE),

the IE contains indication information indicating that the first PDR is applicable to more than one Sx session, and

the indication information includes a group session identifier identifying two or more Sx sessions to which the first PDR is applicable or the indication information indicates that first PDR is applicable to all Sx sessions associated with the second network node, and

said two or more Sx sessions include a first Sx session;

receive a packet;

perform Sx session look-up to identify an Sx session to which the received packet corresponds, wherein the identified Sx session is the first Sx session;

determine that a group of one or more PDRs is applicable to the first Sx session, wherein the group of one or more PDRs includes the first PDR; and

apply the first PDR.