Lawful interception for VoIP calls in IP based networks

• US 20040202295A1
• Filed: 07/25/2003
• Published: 10/14/2004
• Est. Priority Date: 08/08/2002
• Status: Abandoned Application

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Gorges, Thomas, Shen, Yuzhong
• Application Number:
  US10/626,596
• Publication Number:
  US 20040202295A1
• Time in Patent Office: Days
• US Class Current: 379/112.01
• CPC Class Codes: H04L 63/306 intercepting packet switched data communications, e.g. Web, Internet or IMS communications
• CPC Class Codes: H04L 65/1079 of unsolicited session attempts, e.g. SPIT
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04M 3/2281 Call monitoring, e.g. for law enforcement purposes; Call tracing; Detection or prevention of malicious calls
• CPC Class Codes: H04M 3/42221 Conversation recording systems at the subscriber's set H04M1/656
• CPC Class Codes: 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
• CPC Class Codes: H04W 12/80 Arrangements enabling lawful interception [LI]

Abstract

The lawful interception device to monitor media streams of two IP parties includes an SIP (Session Initiation Protocol) proxy server or an MGC (Media Gateway Controller) to detect information in the signalling information being transmitted between the two IP (Internet Protocol) parties and to generate instructions out of the detected signalling information for instructing an RTP (Real-time Transport Protocol) proxy server to create channels to bypass a media stream to be intercepted via an intermediate storage medium. Due to adaptation of connection parameters in the SDP part of the SIP messages sent to the IP parties the interception is transparent to the IP parties.

Claims

1. Lawful interception device including an SIP (Session Initiation Protocol) proxy server or an MGC (Media Gateway Controller) to detect information in the signalling information being transmitted between two IP (Internet Protocol) parties and to generate instructions out of the detected signalling information for instructing an RTP (Real-time Transport Protocol) proxy server to create channels to bypass a media stream to be intercepted via an intermediate storage medium.

2. SIP interception proxy server to detect information in the signalling information being transmitted between two IP (Internet Protocol) parties and to generate instructions out of the detected signalling information for instructing an RTP (Real-time Transport Protocol) proxy server to create channels to bypass a media stream to be intercepted via an intermediate storage medium.

3. Interception MGC to detect information in the signalling information being transmitted between two IP (Internet Protocol) parties and to generate instructions out of the detected signalling information for instructing an RTP (Real-time Transport Protocol) proxy server to create channels to bypass a media stream to be intercepted via an intermediate storage medium.

4. Method for performing SIP signaling for a media stream, including the following steps:

receiving an SIP invite message of a first IP party,

adapting at least one connection parameter in the SDP (Session Description Protocol) of the received SIP invite message,

transmitting the adapted SIP invite message to a second IP party,

receiving an SIP response message of the second IP party,

adapting at least one connection parameter in the SDP (Session Description Protocol) of the received SIP response message,

transmitting the adapted SIP response message to the first IP party.

5. Method according to claim 4, wherein at least one connection parameter includes information about a bypass channel, an address, or a port.

6. Method according to claim 4, wherein the connection parameters sent to both IP parties differ from each other.

7. Computer program for performing at least part of the steps of the method according to claim 4, including the following steps:

adapting at least one connection parameter in the SDP (Session Description Protocol) of the received SIP invite message,

adapting at least one connection parameter in the SDP (Session Description Protocol) of the received SIP response message.