Method for call establishment over a packet exchange network

摘要

The present invention provide a method for call establishment over a packet exchange network which is capable of saving the time required for a call establishment of the PPP by reducing redundant steps for authentication in a SIP call, and to reduce the incoming data amount. The present invention comprising the following steps. Step (a): The TE requests the PDSN for CHAP authentication. This message is received by the AT on behalf of the PDSN. Step (b): The AT requests the TE for the CHAP authentication on behalf of the PDSN, and the maximum packet size MRU receivable by the PTSN is transmitted to the TE. Step (c): The AT accepts the CHAP authentication on behalf of the PDSN. Step (d): The TE accepts the CHAP authentication and the MRU of the PDSN. This message is also received by the AT on behalf of the PDSN.