Method, apparatus, system, and device for managing a session corresponding to multiple session management function network elements

A method, comprising:

• receiving, by a first session management function network element, a request message from a second session management function network element, wherein the request message requests to establish a new branch of a session, and the session comprises an established branch corresponding to a first anchor user plane function network element managed by the second session management function network element;
• selecting, by the first session management function network element, a second anchor user plane function network element corresponding to the new branch of the session;
• selecting, by the first session management function network element, a branching point user plane function network element, wherein the branching point user plane function network element is connected with an access network element, the first anchor user plane function network element, and the second anchor user plane function network element;
• allocating, by the first session management function network element, internet protocol (IP) information of a terminal device to the new branch of the session based on the second anchor user plane function network element;
• and
• sending, by the first session management function network element, the IP information of the terminal device to the second session management function network element.

A method, comprising:

• receiving, by a first session management function network element, a request message from a second session management function network element, wherein the request message requests to establish a new branch of a session, and the session includes an established branch corresponding to a first anchor user plane function network element managed by the second session management function network element;
• selecting, by the first session management function network element, a second anchor user plane function network element corresponding to the new branch of the session;
• allocating, by the second anchor user plane function network element, tunnel information of the second anchor user plane function network element;
• sending, by the second anchor user plane function network element, the tunnel information of the second anchor user plane function network element to the first session management function network element;
• allocating, by the first session management function network element, internet protocol (IP) information of a terminal device to the new branch of the session based on the selected second anchor user plane function network element;
• and
• sending, by the first session management function network element, the IP information of the terminal device to the second session management function network element.

A system, comprising:

• a first session management function network element, configured to:
• receive a request message from a second session management function network element, wherein the request message requests to establish a new branch of a session, and the session includes an established branch corresponding to a first anchor user plane function network element managed by the second session management function network element;
• select a second anchor user plane function network element corresponding to the new branch of the session;
• allocate internet protocol (IP) information of a terminal device to the new branch of the session based on the selected second anchor user plane function network element;
• and
• send the IP information of the terminal device to the second session management function network element;
• and
• the second anchor user plane function network element, configured to allocate tunnel information of the second anchor user plane function network element, and to send the tunnel information of the second anchor user plane function network element to the first session management function network element.

A program product comprising executable instructions stored in a non-transitory readable storage medium, wherein the executable instructions, when executed by at least one processor of a first session management function network element, cause the first session management function network element to:

• receive a request message from a second session management function network element, wherein the request message requests to establish a new branch of a session, and the session includes an established branch corresponding to a first anchor user plane function network element managed by the second session management network element;
• select a second anchor user plane function network element corresponding to the new branch of the session;
• select a branching point user plane function network element, wherein the branching point user plane function network element is connected with an access network element, the first anchor user plane function network element, and the second anchor user plane function network element;
• allocate internet protocol (IP) information of a terminal device to the new branch of the session based on the selected second anchor user plane function network element;
• and
• send the IP information of the terminal device to the second session management function network element.