US 12,192,251 B2
Proxy-call session control function (P-CSCF)
Nassereddine Sabeur, Bellevue, WA (US); Saqib Badar, Bellevue, WA (US); Shujaur Mufti, Snoqualmie, WA (US); Joel Arends, Renton, WA (US); and Subramania Kaushik, Bellevue, WA (US)
Assigned to T-Mobile USA, Inc., Bellevue, WA (US)
Filed by T-Mobile USA, Inc., Bellevue, WA (US)
Filed on Oct. 13, 2021, as Appl. No. 17/500,845.
Prior Publication US 2023/0115970 A1, Apr. 13, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 65/1069 (2022.01); H04L 41/0654 (2022.01); H04L 65/1073 (2022.01)
CPC H04L 65/1069 (2013.01) [H04L 41/0654 (2013.01); H04L 65/1073 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of providing a data traffic session, the method comprising:
receiving, by a unified data management function (UDM), a proxy-call session control function (P-CSCF) restoration indication over a single N70 interface extending directly between the UDM and a serving-call session control function (S-CSCF);
based on at least receiving the SIP message, transmitting, by the UDM, the P-CSCF restoration indication to a session management function (SMF) responsive to receiving the P-CSCF restoration indication over the single N70 interface;
based on at least receiving the P-CSCF restoration indication, sending, from the SMF to a user equipment (UE), an internet protocol (IP) messaging system (IMS) Packet Data Network (PDN) connection release message instructing the UE to release registration with a first P-CSCF and re-register with a second P-CSCF that is different than the first P-CSCF;
receiving an indication, by an application server (AS), that the UE is registered with the second P-CSCF; and
based on at least receiving a session initiation message, establishing the data traffic session for the UE with the second P-CSCF.