Tunnel failure signaling procedures
A user plane function (UPF) receives, from a control plane function (CPF), a request to establish a layer 2 tunneling protocol (L2TP) tunnel for a first protocol data unit (PDU) session of a wireless device. The UPF sends, to the CPF, a message comprising a tunnel failure cause for the establishment of the L2TP tunnel for the first PDU session. The message indicating at least one of a L2TP tunnel failure of the L2TP tunnel, or a L2TP session failure associated with the L2TP tunnel.
1 . A method comprising:
receiving, by a user plane function (UPF) from a control plane function (CPF), a request to establish a layer 2 tunneling protocol (L2TP) tunnel between the UPF and an L2TP network server (LNS) for a first protocol data unit (PDU) session of a wireless device, wherein the UPF supports an L2TP service;
determining, by the UPF, a failure of the L2TP tunnel establishment; and
sending, by the UPF to the CPF and based on the determining, a message comprising a tunnel failure cause for the L2TP tunnel indicating:
an L2TP tunnel failure of the L2TP tunnel; and
that an L2TP access concentrator (LAC) and LNS pair connection between the UPF and the LNS does not exist;
wherein the UPF comprises the LAC.
2 . The method of claim 1 , wherein the CPF comprises a session management function (SMF).
3 . The method of claim 1 , wherein the L2TP tunnel is between the UPF and an L2TP server for the wireless device.
4 . The method of claim 1 , wherein the message further comprises a tunnel failure indication indicating a failed tunnel.
5 . The method of claim 1 , wherein the message further comprises an address of a tunnel server endpoint for a failed tunnel.
6 . The method of claim 1 , wherein the tunnel failure cause comprises an information element indicating at least one of:
a physical link failure of the tunnel;
a permanent failure of the tunnel;
a temporary failure of the tunnel; or
a tunnel session failure.
7 . The method of claim 1 , wherein the message further comprises a tunnel type comprising at least one of:
an L2TP tunnel version 2;
an L2TP tunnel version 3;
a generic routing encapsulation (GRE) tunnel;
an IP-in-IP tunnel; or
a GPRS tunnelling protocol (GTP) tunnel.
8 . A user plane function comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the user plane function (UPF) to:
receive, from a control plane function (CPF), a request to establish a layer 2 tunneling protocol (L2TP) tunnel between the UPF and an L2TP network server (LNS) for a first protocol data unit (PDU) session of a wireless device, wherein the UPF supports an L2TP service;
determine a failure of the L2TP tunnel establishment; and
send, to the CPF, a message comprising a tunnel failure cause for the L2TP tunnel indicating:
an L2TP tunnel failure of the L2TP tunnel; and
that an L2TP access concentrator (LAC) and LNS pair connection between the UPF and the LNS does not exist;
wherein the UPF comprises the LAC.
9 . The user plane function of claim 8 , wherein the CPF comprises a session management function (SMF).
10 . The user plane function of claim 8 , wherein the L2TP tunnel is between the UPF and an L2TP server for the wireless device.
11 . The user plane function of claim 8 , wherein the message further comprises a tunnel failure indication indicating a failed tunnel.
12 . The user plane function of claim 8 , wherein the message further comprises an address of a tunnel server endpoint for a failed tunnel.
13 . The user plane function of claim 8 , wherein the tunnel failure cause comprises an information element indicating at least one of:
a physical link failure of the tunnel;
a permanent failure of the tunnel;
a temporary failure of the tunnel; or
a tunnel session failure.
14 . The user plane function of claim 8 , wherein the message further comprises a tunnel type comprising at least one of:
an L2TP tunnel version 2;
an L2TP tunnel version 3;
a generic routing encapsulation (GRE) tunnel;
an IP-in-IP tunnel; or
a GPRS tunnelling protocol (GTP) tunnel.
15 . A non-transitory computer-readable medium storing instructions that, when executed by the one or more processors of a user plane function (UPF), cause the UPF to:
receive, from a control plane function (CPF), a request to establish a layer 2 tunneling protocol (L2TP) tunnel between the UPF and an L2TP network server (LNS) for a first protocol data unit (PDU) session of a wireless device, wherein the UPF supports an L2TP service;
determine a failure of the L2TP tunnel establishment; and
send, to the CPF, a message comprising a tunnel failure cause for the L2TP tunnel indicating:
an L2TP tunnel failure of the L2TP tunnel; and
that an L2TP access concentrator (LAC) and LNS pair connection between the UPF and the LNS does not exist;
wherein the UPF comprises the LAC.
16 . The non-transitory computer-readable medium of claim 15 , wherein the CPF comprises a session management function (SMF).
17 . The non-transitory computer-readable medium of claim 15 , wherein the L2TP tunnel is between the UPF and an L2TP server for the wireless device.
18 . The non-transitory computer-readable medium of claim 15 , wherein the message further comprises a tunnel failure indication indicating a failed tunnel.
19 . The non-transitory computer-readable medium of claim 15 , wherein the message further comprises an address of a tunnel server endpoint for a failed tunnel.
20 . The non-transitory computer-readable medium of claim 15 , wherein the tunnel failure cause comprises an information element indicating at least one of:
a physical link failure of the tunnel;
a permanent failure of the tunnel;
a temporary failure of the tunnel; or
a tunnel session failure.