| 摘要 |
<p>A mobile station can be provided with necessary information of call state control functions, especially in case of roaming without expenditure when using a proxy call state control function (P-CSCF) acting as a border element and controlling local services and occasionally necessary resources within this network. According to a preferred embodiment the selected call state control function (CSCF) acts as a redirect server and redirects a session initiation protocol (SIP) request to another, especially an (CSCF).</p> |
