a plurality of signal processing units that are disposed for a plurality of channels thereof, respectively, each configured to perform data processing on data transmitted via a corresponding one of said plurality of channels;

a device alarm monitoring control unit configured to monitor occurrence of a failure in said plurality of signal processing units;

a failure-occurrence-data generating unit configured to generate failure occurrence data on a channel by channel basis including failure occurrence data about a channel corresponding to one of said plurality of signal processing units in which a failure has occurred based on failure occurrence information notified thereto by said device alarm monitoring control unit;

a packet assembling unit configured to packetize said failure occurrence data so as to generate failure occurrence packet data;

a packet transmitting unit configured to transmit the failure occurrence packet data generated by said packet assembling unit to said other gateway apparatus which is disposed opposite to said gateway apparatus;

a packet receiving unit configured to receive failure occurrence packet data transmitted thereto from said other gateway apparatus which is disposed opposite to said gateway apparatus;

a packet disassembling unit configured to disassemble the failure occurrence packet data received by said packet receiving unit so as to extract failure occurrence data;

a failure-occurrence-data analysis unit configured to analyze the failure occurrence data extracted by said packet disassembling unit so as to determine if a channel of said other gateway apparatus in which a failure has occurred corresponds to which channel of said gateway apparatus; and

a failure occurrence information output unit configured to notify failure occurrence information provided on a channel by channel basis to a local station side based on an analysis result obtained by said failure-occurrence-data analysis unit.