Patent ID: 8924718

Claim:
A method, comprising: performing, by a telecommunications monitoring system: identifying a Security Association (SA) between a User Equipment (UE) and a Proxy Call Session Control Function (P-CSCF) of an Internet Protocol (IP) Multimedia Subsystem (IMS) over a Gm interface during a registration procedure wherein identifying the SA includes identifying a first SA pair and a second SA pair, wherein the first SA pair includes: (a) a UE client SPI value and UE IP address and (b) a UE server SPI value and UE IP address, and wherein the second SA pair includes (a) a P-CSCF client SPI value and P-CSCF IP address and (b) a P-CSCF server SPI value and P-CSCF IP address; correlating the SA with a ciphering key (CK) exchanged between the P-CSCF and a Serving CSCF (S-CSCF) of the IMS over an Mw interface during the registration procedure; and storing an indication of the correlated SA and CK in a deciphering record.