The telecommunications market is changing and it makes that telecommunications operators search for a way to offer new and attractive services for its users. This is even more important when the mobile networks infrastructure update process is considered. Latin-American operators are planning to introduce 3G networks technology on the region. However, these changes imply great inversions too. This paper presents a proposal to offer services based on Session Initiation Protocol (SIP) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> with a low cost platform based on market tendencies adopting initiatives as 3GPP IP Multimedia Subsystem (IMS).