Abstract: A method in a telecommunication system for monitoring a communication by a Law Enforcement Monitoring Facility (LEMF). The LEMF sends a request for monitoring of a first party to a Call Session Control Function (CSCF) in a service domain of the telecommunication system. When the CSCF detects a SIP session event due to a setup of a media-flow connection between the monitored party and a second party, the CSCF sends Interception Related Information (IRI) toward the LEMF, and sends a resource setup message to a Multimedia Resource Function (MRF), also in the service domain. A Gateway GPRS Support Node (GGSN) routes the Communication Content (CC) to the MRF. The MRF copies the CC and routes one copy back to the GGSN and routes the other copy to the LEMF via a Delivery Function utilizing a SIP session with the LEMF.

Abstract: The present invention relates to a method for monitoring in a telecommunication system. The system comprises a service domain that handles session control and a bearer domain used for transportation of media flow. A request for monitoring of a first party (A) is received by a Call Session Control Function (CSCF) in the service domain. The method comprises the following further steps: —A SIP session event is detected by the Call 10 Session Control Function (CSCF) due to a set-up of a media-flow connection between the monitored party (A) and a second party (B). —A resource set-up message (SIP1) is sent via an interface (Mr) from the Call Session Control Function (CSCF) to a Multimedia Resource Function (MRF) in the service domain. —A SIP transaction is established between the Multimedia Resource Function (MRF) and a third Delivery Function (DF3). —A SIP session is established between the third Delivery Function (DF3) and a Law Enforcement Monitoring Facility (LEMF).