Universal Mobile Telecommunications System (UMTS) as a 3rd generation network with its architecture belong to the next generation networks concept. The model for multimedia session parameters control described in this work is based on the UMTS architecture, especially on the IP Multimedia Subsystem (IMS) architecture and Session Initiation Protocol (SIP). Multimedia services can be approached through IMS by variety of different access terminals from different access networks. The end user should also be able to specify his preferences about the service. Inside this work the 3rd generation network architecture was analyzed, with emphasis on standards for session description and session control. Based on the analysis the model for session parameters control was proposed. Proposed model deals with the problem of multi terminal access to the multimedia service with an ability of an end user preferences specification. Special attention was given to the multimedia session parameters that specify streaming of multimedia content. The model is built from several function entities that enable description of user preferences and terminal capabilities, and selection of appropriate multimedia service. The model consists of the following entities: client, final client profile creation process, service profiles, and matching process. The model enables the end user to choose a client profile, and send it to the SIP proxy server by use of client’s SIP user agent. The final client profile is made inside the final client profile process based on parameters from subscriber profile and received client profile. The matching process determines a set of potential service parameters based on parameters from service profile and final client profile. Most appropriate service is selected and sent to the end user after the end user approves the set of potential service parameters. SIP was used as the main signalization protocol inside the model. Model function entities were mapped to IMS entities, implemented and verified on the prototype application inside the laboratory testbed.