# US 9,521,203 B2 · Communication session processing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,521,203 B2 - Document ID: US9521203B2 - Status: Granted - Kind: B2 - Application number: 14/850,761 - Filed: 2015-09-10 - Published: 2016-03-10 - Granted: 2016-12-13 - Earliest claimed: 2011-07-11 - Assignees: Metaswitch Networks Ltd. - Applicants: Metaswitch Networks Ltd - Inventors: Oliver James Carter; Christopher Richard Gibbs; Oliver Fairless Nicolson; Phillip James Springett - Web page: https://patentgrep.com/patent/US9521203B2 ## CPC - H04L 65/1104: Session initiation protocol [SIP] - H04L 9/0631: {Substitution permutation network [SPN], i.e. cipher composed of a number of stages or rounds each involving linear and nonlinear transformations, e.g. AES algorithms} - H04L 65/104: {in the network} - H04L 65/1043: Gateway controllers, e.g. media gateway control protocol [MGCP] controllers - H04L 65/80: Responding to QoS - H04L 67/146: Markers for unambiguous identification of a particular session, e.g. session cookie or URL-encoding - H04M 7/006: {Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer (H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42)} - H04L 63/0428: {wherein the data content is protected, e.g. by encrypting or encapsulating the payload} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) ## Abstract Measures for use in processing communication sessions in a telecommunications network are provided. Each communication session has a signaling path spanning a plurality of devices including one or more intermediate network devices and at least two endpoint devices, the signaling path comprising a plurality of signaling segments, each segment being between two devices in the plurality of devices. A first signaling message, comprising a first identifier associated with the communication session, is received via a first signaling segment for a communication session. At least part of the first identifier is transformed using a deterministic encryption algorithm to generate a second identifier. A second signaling message, comprising the second identifier, is transmitted via a second signaling segment for the communication session to associate the second identifier with the communication session. ## Claims ### Claim 1 A method of processing communication sessions in a telecommunications network, each communication session having a signaling path spanning a plurality of devices including one or more intermediate network devices and at least two endpoint devices, the signaling path comprising a plurality of signaling segments, each segment being between two devices in the plurality of devices, the method comprising: receiving, via a first signaling segment for a communication session, a first signaling message comprising a first identifier associated with the communication session; transforming at least part of the first identifier using a deterministic encryption algorithm to generate a second identifier; and transmitting, via a second signaling segment for the communication session, a second signaling message comprising the second identifier to associate the second identifier with the communication session. ### Claim 2 (depends on 1) The method of claim 1, wherein the first signaling message comprises a first communication session setup signaling message for the communication session and the second signaling message comprises a second communication session setup signaling message for the communication session. ### Claim 3 (depends on 1) The method of claim 1, further comprising: receiving a third signaling message comprising the first identifier; transforming at least part of the first identifier from the third signaling message using the deterministic encryption algorithm to generate the second identifier associated with the communication session; and transmitting a fourth signaling message comprising the second identifier generated by the transformation of at least part of the first identifier from the third signaling message. ### Claim 4 (depends on 3) The method of claim 3, wherein the third signaling message comprises a first quality reporting signaling message for the communication session and is received via the first signaling segment, and the fourth signaling message comprises a second quality reporting signaling message and is transmitted via the second signaling segment. ### Claim 5 (depends on 4) The method of claim 4, wherein the first quality reporting signaling message is received during the communication session. ### Claim 6 (depends on 4) The method of claim 4, wherein the first quality reporting signaling message is received after termination of the communication session. ### Claim 7 (depends on 1) The method of claim 1, wherein the first identifier is received at an intermediate network device, the method further comprising: determining that the received first identifier does not comprise at least a portion identifying the intermediate network device, wherein the transforming of at least part of the first identifier is carried out in response to the determination. ### Claim 8 (depends on 1) The method of claim 1, further comprising: receiving a third signaling message comprising the second identifier; transforming at least part of the second identifier from the third signaling message using an inverse of the deterministic encryption algorithm to generate the first identifier associated with the communication session; and transmitting a fourth signaling message comprising the first identifier generated from the transformation of at least part of the second identifier from the third signaling message. ### Claim 9 (depends on 8) The method of claim 8, wherein the third signaling message comprises a first quality reporting signaling message for the communication session and is received via the second signaling segment, and the fourth signaling message comprises a second quality reporting signaling message and is transmitted via the first signaling segment. ### Claim 10 (depends on 8) The method of claim 8, wherein the second identifier is received at an intermediate network device, the method further comprising: determining that the received second identifier comprises at least a portion identifying the intermediate network device, wherein the transforming of at least part of the second identifier is carried out in response to the determination. ### Claim 11 (depends on 1) The method of claim 1, wherein the first signaling message comprises a first quality reporting signaling message for the communication session and the second signaling message comprises a second quality reporting signaling message for the communication session. ### Claim 12 (depends on 1) The method of claim 1, further comprising detecting that the first signaling message is of a communication session quality reporting type, wherein the transformation is carried out in response to the detection. ### Claim 13 (depends on 1) The method of claim 1, wherein the first identifier includes a portion comprising a network address for at least one device in the signaling path of the communication session. ### Claim 14 (depends on 13) The method of claim 13, wherein the at least one device comprises an endpoint device, and the first signaling message is generated by the endpoint device. ### Claim 15 (depends on 13) The method of claim 13, wherein the at least one device comprises a softswitch, and the first signaling message is generated by the softswitch. ### Claim 16 (depends on 1) The method of claim 1, wherein the communication session comprises a Session Initiation Protocol (SIP) communication session, the first and second signaling messages comprise first and second SIP signaling messages, and the first and second identifiers are session identifiers contained in respective session identifier fields of the first and second SIP signaling messages. ### Claim 17 (depends on 16) The method of claim 16, wherein the first and second signaling messages comprise one or more of: SIP INVITE messages, SIP SUBSCRIBE messages, SIP REFER messages, SIP NOTIFY messages, and SIP PUBLISH messages. ### Claim 18 (depends on 1) The method of claim 1, wherein the transformation of the first identifier is carried out by a session border controller located between the first and second signaling segments, the transformation is applied to the entire contents of the first identifier and the result of the transformation is added as a prefix to a network address of the session border controller to form the second identifier. ### Claim 19 (depends on 1) The method of claim 1, wherein the deterministic encryption algorithm comprises one of Advanced Encryption Standard™ and Rivest Cipher 4™. ### Claim 20 A session border controller for processing communication sessions in a telecommunications network, each communication session having a signaling path spanning a plurality of devices including one or more session border controllers, a softswitch and at least two endpoint devices, the signaling path comprising a first signaling segment located between one of the endpoint devices and the session border controller, and a second signaling segment located between the session border controller and the softswitch, the session border controller comprising: a first interface configured to receive, via the first signaling segment for a communication session, a first signaling message comprising a first identifier associated with the communication session; a processor configured to transform at least part of the first identifier using a deterministic encryption algorithm to generate a second identifier; and a second interface configured to transmit, via the second signaling segment for the communication session, a second signaling message comprising the second identifier to associate the second identifier with the communication session. ### Claim 21 A computer program product comprising a non-transitory computer-readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerized device to perform a method for processing communication sessions in a telecommunications network, each communication session having a signaling path spanning a plurality of devices including one or more intermediate network devices and at least two endpoint devices, the signaling path comprising a plurality of signaling segments, each segment being between two devices in the plurality of devices, the method comprising: receiving, via a first signaling segment for a communication session, a first signaling message comprising a first identifier associated with the communication session; transforming at least part of the first identifier using a deterministic encryption algorithm to generate a second identifier; and transmitting, via a second signaling segment for the communication session, a second signaling message comprising the second identifier to associate the second identifier with the communication session.