FIELD: information technology.
SUBSTANCE: present invention relates to data transfer networks. A communication session request message (S1) is sent. In response to the session request message, additional information is extracted and included in the session request message (from S2 to S8). A communication session (S12) is established based on information in the resultant session request message. The communication session can be established between first and second devices (102, 104) using Session initiation protocol (SIP). The additional information contains brief information, from which complete information can successively be determined using the second device (104), after the session has been established. Complete information is stored on a mail server (114) and brief information, separate from the complete information, is stored in a data base (112).Brief information in data base (112) is synchronised (S5, S6) with complete information in mail server (114). Brief information is extracted (S4, S6) from the data base (112) for inclusion (S8) in the additional information, so as to provide the second device (104) with the possibility of successive extraction (Q1, Q2) of complete information from the mail server (114), related to the brief information.
EFFECT: more functional capabilities when using SIP.
27 cl, 7 dwg
