| 摘要 |
PURPOSE: A time synchronization system between an SGSN(Serving GPRS Support Node) and a GGSN(Gateway GPRS Support Node) and a method therefor are provided to execute fault monitoring and NTP(Network Time Protocol) server changing, when a fault occurs in an NTP server, so that the time synchronization can be guaranteed till the restoration of the fault. CONSTITUTION: A GGSN monitors whether a fault occurs in an NTP server. If a fault occurs in the NTP server, the GGSN transmits an NTP server change request packet to a plurality of SGSNs in order to make an NTP server change request(S601). Each SGSN, in response to the NTP server change request packet received from the GGSN, transmits an NTP server change response packet, changes NTP servers according to the NTP server change request, and makes a time synchronization with the GGSN through time distributed from the changed NTP server(S602). The GGSN, receiving the NTP server change response packets from the SGSNs, confirms that the SGSN have changed NTP servers(S603). |
